American martens can live for up to 17 years in captivity. Although martens in the wild probably do not live as long as those in captivity, wild females are still able to breed at the age of 12 years.
Range lifespan
Status: captivity: 17 (high) years.
Average lifespan
Status: captivity: 17.0 years.
Martes americana is found primarily in mature, northern forests. These animals are closely associated with lodgepole pine, Douglas fir, spruce, and mixed harwood forests. They tend to be found in structurally complex, mature forests, and can occur at all elevations where such habitat exists. They den in hollow trees, crevices, or vacant ground burrows.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: taiga ; forest
American martens, Martes americana, are found in the northern reaches of North America. The species is present from Newfoundland and Nova Scotia west to Alaska and south into sections of the rocky mountain range and California. Martens are found sporadically in parts of New York state, Michigan, Minnesota, Maine, and Wisconsin. Although populations were greater in the southeastern portion of the species range in Colonial times, loss of forest habitat in these areas has restricted their range. Programs for reintroduction of these animals in Minnesota and Ontario may help populations to recover.
Biogeographic Regions: nearctic (Native )
Martes americana is an opportunistic feeder. The diet consists primarily of small mammals, including squirrels and rodents. Occasionally birds, fruit, nuts, insects, and carrion are eaten as well. American martens usually kill their prey with a quick, powerful bite to the back of the prey animal's neck. American martens sometimes have fast-paced chases in trees with a favorite prey item, red squirrels.
Animal Foods: birds; mammals; amphibians; reptiles; eggs; carrion ; insects
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: carnivore (Eats terrestrial vertebrates)
As predators, American martens may have significant impact on prey populations, helping to structure the forest community.
Marten pelts are very valuable and are taken in controlled hunts.
Positive Impacts: body parts are source of valuable material
Male American martens measure 360 to 450 mm, with the tail adding 150 to 230 mm more. Weights of males range between 470 and 1,300 g. Females are slightly smaller and lighter, with head-body lengths between 320 and 400 mm, and tails measuring 135 to 200 mm. Females weigh betweeen 280 and 850 g.
The fur is long and shiny. The head is gray, legs and tail are very dark brown or black, the chest has a cream colored patch, and the back is light brown.
American martens are long, slender animals. Eyes are large and ears are cat-like. Claws are sharp and curved.
Range mass: 280 to 1,300 g.
Range length: 320 to 450 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Average basal metabolic rate: 3.579 W.
Predators have not been reported for American martens. However, it is likely that young martens may be vulnerable to large carnivores like wolves or owls.
This species could possibly be considered a pest, in that it reduces the population of game species such as squirrels and rabbits. However, they live in areas that are usually sparsely populated by humans and are not likely to impacts humans.
Collection of pelts has reduced populations in many parts of the species range. The destruction of coniferous forest habitat has also led to decreased numbers. In spite of these threats, American martens are not considered endangered.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
American martens have complex means of communication. In addition to the scent marking so common in Mustelidae, they use vocalizations (huffs, chuckles, and screams). Physical contact is important between mates as well as between mothers and their offspring. The role of visual cues in communication has not been reported, but in many Mustelids, body postures play an important role in communication. It is likely that these animals are similar to other members of their family in this respect.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Mating has been described as polygynous. During estrus, females use scent marks to advertize their sexual condition. Courtship between males and females can be quite protracted, and involves tumbling, playing and wrestling. In captivity, females reportedly exhibit between 1 and 4 periods of sexual receptivity, each of which lasts from 1 to 4 days. These occur at 6 to 17 day intervals throughout the breeding season.
Mating System: polygynous
The breeding season occurs from June to August. Implantation of the fertilized eggs is delayed, and does not take place until February. Although the total period of pregancy is between 220 and 275 days, after implantation in the uterine lining, the embryos develop for only 28 days. The 1 to 5 blind young (kits) are born in late March or early April in dens lined with dried plant material.
The young grow quickly. Eyes open by the age of 39 days. Young martens are weaned after 42 days. Full size is reached very quickly, around 3.5 months after birth. Sexual maturity is reached at 15 to 24 months of age.
Breeding interval: Females may breed four times in a season at 6-17 day intervals. Breeding season occurs once per year.
Breeding season: Breeding season is in June to August.
Range number of offspring: 1 to 5.
Average number of offspring: 2.6.
Range gestation period: 220 to 275 days.
Average weaning age: 42 days.
Range age at sexual or reproductive maturity (female): 15 to 24 months.
Range age at sexual or reproductive maturity (male): 15 to 24 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous ; delayed implantation
Average birth mass: 30 g.
Average number of offspring: 3.
Information on the parental behavior of these animals is not readily available. However, as mammals, we know that the female nurses her offspring and provides them with protection and a home for the first part of their lives. Even though the role of males in parental care is not clear,adult males and females have been seen together with immature animals, presumably their offspring. Although American martens are larely solitary, it is still possible that males have some association with their offspring during rearing.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The direct effects of fire on American marten are likely minimal. Reviews suggest that medium to large mammals are typically mobile enough to avoid fire, though mortality may result from large, fast-moving fires [108,114,130]. Biologists in southeastern Manitoba documented a juvenile American marten male and a juvenile female surviving a 160,000-acre (65,000 ha) mixed-severity wildfire in May. Neither animal appeared to be burned by the fire [139]. Following an extensive but low-severity fire in central Alaska, a trapper observed American marten tracks amid smoldering ground after early autumn snowfalls [88].
Because American marten kits are largely immobile until approximately 12 to15 weeks old [187,188] and both ground and arboreal denning structures may be destroyed by fire, kits may be vulnerable to mortality during spring fires (review by [68]).
Diseases: American marten host several internal and external parasites, including helminths, fleas (Siphonaptera), and ticks (Ixodida) (review by ([165]). American marten in central Ontario carried both toxoplasmosis and Aleutian disease, but neither affliction was suspected to cause significant mortality [166]. High American marten mortality in Newfoundland was caused by encephalitis [59].
Sources of Mortality: American marten are susceptible to predation and mortality from other natural causes. Trapping pressure causes high mortality in some areas.
Predators: American marten are vulnerable to predation from raptors and other carnivores. Some authors suggest that the threat of predation may be an important factor shaping American marten habitat preferences, a hypothesis inferred from their avoidance of open areas and from behavioral observations of the Eurasian pine marten (Martes martes) (review by [28]).
Specific predators vary by geographic region. In Newfoundland, red foxes (Vulpes vulpes) were the most frequent predator, though coyote (Canis latrans) and other American marten were also responsible for some deaths [80]. In deciduous forests in northeastern British Columbia, most predation was attributed to raptors [132]. Of 18 American marten killed by predators in northeastern Oregon, 8 were killed by bobcats (Lynx rufus), 4 by raptors, 4 by other American marten, and 2 by coyotes. Throughout the distribution of American marten, other predators include the great horned owl (Bubo virginianus), bald eagle (Haliaeetus leucocephalus), golden eagle (Aquila chrysaetos), Canada lynx (L. canadensis), mountain lion (Puma concolor) (reviews by [38,166]), fisher (M. pennanti) [139,142], wolverine (Gulo gulo), grizzly bear (Ursus arctos horribilis), American black bear (U. americanus), and gray wolf (C. lupus) [178]. In northeastern Oregon, most predation (67%) occurred between May and August, and no predation occurred between December and February [20].
Other sources of mortality: Trapping is a major source of mortality in some areas. In east-central Alaska, 72% of observed mortality was from trapping [150]. Of 28 deaths of known cause in western Quebec, 16 resulted from commercial trapping, and 12 were from natural causes including injury (6), predation (4), starvation (1), and disease (1) [135]. In Newfoundland, 75% of the human-caused mortality was incidental from snares set for snowshoe hares; the remaining 25% was from traps intended for American marten. Natural mortality accounted for 28% of American marten deaths [80]. American marten mortality may be biased towards certain segments of the population; in north-central Maine there was "substantial" predation mortality of transient females [85]. In Newfoundland trapping deaths were biased towards males and juveniles [80].
Other sources of mortality include drowning [168], starvation [59,80,168], exposure [20], choking, and infections associated with injury [80]. During live trapping, high mortality may occur if individuals become wet in cold weather (review by [38]). Several chemical contaminants (PCBs, DDT, mercury, chlordane, mirex, dierldrin) are carried by American marten, though there is no conclusive evidence of harmful effects (review by ([165]).
Survival rates: Survival rates vary by geographic region, exposure to trapping, habitat quality, and age. In an unharvested population in northeastern Oregon, the probability of survival of American marten ≥9 months old was 0.55 for 1 year, 0.37 for 2 years, 0.22 for 3 years, and 0.15 for 4 years. The mean annual probability of survival was 0.63 for 4 years [20]. In a harvested population in east-central Alaska, annual adult survival rates ranged from 0.51 to 0.83 over 3 years of study. Juvenile survival rates were lower, ranging from 0.26 to 0.50 [150]. In Newfoundland, annual adult survival was 0.83. Survival of juveniles from October to April was 0.76 in a protected population, but 0.51 in areas open to snaring and trapping [80]. In western Quebec, natural mortality rates were higher in clearcut areas than in unlogged areas [135].
Life span: American marten in captivity may live for 15 years. The oldest individual documented in a wild population was 14.5 years old (review by [28]).
American marten populations exhibit several characteristics that may inhibit recovery from large-scale disturbances such as fire; these characteristics include generally low population density, low reproductive rates, delayed maturity, and the geographic isolation of some populations (see Management Considerations).
Some sources suggest that prescribed fire may be an appropriate tool for managing forests for American marten [2,114,124], though, as of this writing (2010), no studies had directly studied this topic. The authors of one study caution against using fire as a management tool in the taiga of Alaska, after documenting several population characteristics that suggested recently burned forest may act as a population sink [88] (see Wildfire Case Study 2). The effects of wildfire on American marten depend on several factors, including fire severity ([94,94], reviews by [103,161]), fire pattern [103,161], fire size [22,94,96], time since fire [8,65,94,96,103,139], characteristics of regenerating vegetation [103,161], and local site characteristics ([94,96,161,178], review by [28]) (see Indirect Fire Effects for more information). It is likely the effects of prescribed fire depend on similar factors.
This section summarizes some of the topics to consider before using prescribed fire in areas occupied by American marten, including potential impacts on American marten and a synthesis of fire characteristics that would minimize negative impacts. There is also a brief mention of fire surrogate treatments.
Potential Impacts: As is the case with fire in general [108,114,130], the likelihood of American marten mortality due to prescribed fire is low, with the possible exception of kits if prescribed fires are conducted in the spring denning season (review by [68]). One review reports that mammalian predators such as the American marten have such large home ranges that prescribed fire treatments would likely represent a minimal proportion of their home range [114].
Prescribed fire has the potential to consume denning and resting structures as well as reduce canopy cover, though one source suggests that prescribed fire's impact on protective cover is likely to be negligible [114]. Management recommendations for American marten in British Columbia include avoiding practices such as windrowing and burning, stump removal, or severe broadcast burning because such practices consume woody debris [105]. Suggestions for protecting woody structures include wetting them or burning in moist conditions [70,114] raking debris away from their bases [48,114,175] or applying fire retardant at bases of snags [114]. Downed woody structures or herbaceous vegetation may provide adequate cover in place of canopy cover following prescribed fire; such resource use by American marten has been reported following wildfire ([23,109,123,178], review by [28]), insect outbreaks [126], or logging [81]. For information on wildlife habitat and preservation during and after fires, including information on managing for structures used by American marten, see Brown and Bright [15].
As is the case with wildfire (see Fire effects on food), it is difficult to make broad generalizations about the potential impacts of prescribed fire on American marten food resources due to regional diet preferences and prey habitat variability (see Food Habits). It is likely that prescribed fire will increase the abundance of some food items and decrease the abundance of others. One review suggests that prescribed fire would likely increase the short-term quantity of food available [114]. Within 4 years of a mixed-severity prescribed fire in central Alaska, researchers observed "diggings" of yellow-cheeked voles, a preferred American marten prey item in the area [124]. However, Pilliod and others [130] summarize cases where small mammal populations declined following thinning treatments that included prescribed fire.
Fire characteristics: There are several aspects of prescribed fire to consider when attempting to produce conditions favorable to American marten, including fire season, size, severity, and burn pattern. Fire season is important because American marten kits may be vulnerable to mortality from prescribed fires conducted during the denning season, which begins in late March or April (review by [136]). Several sources recommend small prescribed fires ([91,161], reviews by [22,96]) because small disturbed areas usually require less time to reestablish cover and food than large areas (review by [96]) or may create abundant edge habitat, favored for foraging in some areas [91]. Small fires may also decrease the risk of habitat fragmentation, which is generally thought to negatively affect American marten ([75,80,81,116,180], review by [27]). Johnson and others [88] suggest that large fires with few unburned inclusions would be colonized more slowly than small or patchy fires that may be closer to source populations in unburned forest. Low-severity fires may also be ideal if they maintain canopy cover (review by [96]), though one source suggests fires of variable severity may offer a diversity of resources [161]. Burn pattern is also an important consideration. Unburned inclusions are highly used cover types in areas burned by wildfire [43,53,109,155,161,178] (see Fire effects on cover). Proximity of residual forest may also be important [58,91], particularly if it impacts the ability of American marten to colonize burned areas [2,123]. One source suggests that fires with irregular perimeters are highly beneficial to American marten in Alaska because burn edges are often a center of activity [161]. To minimize the negative impacts of prescribed fires on American marten in south-central Yukon, treatments that leave pockets of mature forest, protect old-growth communities, and allow enough intact forest to allow for immigration and emigration are suggested [2].
Other fire-related treatments: Though the information is sparse and/or indirect, as of this writing (2010), there was some commentary on the impacts of fire-surrogate treatments on American marten. Mechanical fuels reduction treatments in northeastern Oregon led to changes in small mammal populations, including general decreases in populations of northern red-backed voles, red squirrels, and snowshoe hares. Though American marten food habits were not studied, the authors noted that American marten avoided all treated areas [17].
Though details are lacking, managers from central Alaska observed more winter tracks of American marten in quaking aspen stands regenerating after felling compared to stands burned by severe prescribed fire. Both treatments occurred 2 to 6 years previously and top-killed most quaking aspen. Debris was removed from sites where felling occurred. At the time of sampling, both treatment areas had 30,000 stems/ha [122].
Fire is a natural disturbance shaping plant communities across the range of the American marten, including plant communities in Alaska [24,65,150,178], Wisconsin [63,186], Montana [23,181], Idaho [93,96], Washington [94], California [111,159], Northwest Territories [131], , Yukon [3,155], Ontario [1], Manitoba [140,141], and British Columbia [6,106]. American marten occur in plant communities with a wide range of FIRE REGIMES, including FIRE REGIMES characterized by low-severity (e.g., California redwood; Great Lakes maple-basswood), mixed-severity (e.g., California mixed evergreen; Douglas-fir (cold)), or stand-replacement (e.g., Pacific Northwest spruce-fir; persistent lodgepole pine) fire. Return intervals may be either short (e.g., Sierra Nevada lodgepole pine; ponderosa pine (Northern and Central Rockies)) or long (e.g., western redcedar; northern hardwoods-spruce; beech-maple).
The Fire Regime Table summarizes characteristics of FIRE REGIMES for vegetation communities in which American marten may occur. Follow the links in the table to documents that provide more detailed information on these FIRE REGIMES. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find FIRE REGIMES".
American marten also occur in geographic areas not covered by the Fire Regime Table, including a variety of boreal plant communities in Alaska and Canada. On the Kenai Peninsula, mean fire-return intervals ranged from 400 to 600 years for white spruce forest and averaged 79 years for black spruce forest (review by [8]). The boreal white spruce-black spruce biogeoclimatic zone in northeastern British Columbia experienced historic stand-replacing fires approximately every 100 years. Most fires were large (>2,500 acres (1,000 ha)), leaving small amounts of unburned forest (review by [132]). A mean fire-return interval of 69 years was estimated for boreal white spruce forests in Wood Buffalo National Park, Alberta [102]. In the interior taiga of Alaska, black spruce-paper birch/bog blueberry-bog Labrador tea (V. uliginosum-Ledum groenlandicum) and black spruce/bog blueberry-bog Labrador tea/Schreber's moss (Pleurozium schreberi) vegetation types had fire return intervals of less than 100 years [56]. From fire scar data, a mean fire-return interval of 40.4 years was calculated for the jack pine-black spruce/bog Labrador tea/reindeer lichen (Cladonia spp.) vegetation type occupying north-facing slopes and depressions of the Athabasca Plains of northeastern Alberta and northwestern Saskatchewan [33].
Fire regime change: Climate change may have important implications for FIRE REGIMES in areas where American marten occur. One author suggested that fire frequency on the Kenai Peninsula may be increasing in response to warmer summer temperatures, causing a potential decline in suitable American marten habitat [8]. There is some concern that fire exclusion has increased fuel loads, altering historical FIRE REGIMES and resulting in severe fires that could negatively impact American marten habitat (review by [96]). However, since fire regime characteristics across the distribution of American marten are variable, it is difficult to say how representative this assertion is for all American marten habitats.
American marten are opportunistic predators, influenced by local and seasonal abundance and availability of potential prey (review by [136]). They require about 80 kcal/day while at rest, the equivalent of about 3 voles (Microtus, Myodes, and Phenacomys spp.) (review by ([165]). Voles dominate diets throughout the American marten's geographic range (review by [136]), though larger prey—particularly snowshoe hares [42,139,142]—may be important, particularly in winter [61,148]. Red-backed voles (Myodes spp.) are generally taken in proportion to their availability, while meadow voles (Microtus spp.) are taken in excess of their availability in most areas. Deer mice (Peromyscus maniculatus) and shrews (Soricidae) are generally eaten less than expected, but may be important food items in areas lacking alternative prey species (review by [28]). Birds were the most important prey item in terms of frequency and volume on the Queen Charlotte Islands, British Columbia [118]. Fish may be important in coastal areas [9,118]. See Martin [112] for a review of American marten feeding ecology, including a summary of 22 studies on food use. For additional information on specific food items consumed by American marten, see the following sources: Alaska [9,29,88,109,123], Maine [61,158], Wyoming [30,76], Montana [181], Idaho [94,96,110], California [74,111,152,190], Oregon [16], Labrador [151], Northwest Territories [49,115,131], Ontario [42,58,169,171], Manitoba [139,142], and British Columbia [6,118].
Habitat preferences of dominant prey items are extremely variable. Red-backed voles prefer coniferous forests, where they are associated with large-diameter logs and understory cover. Meadow voles (Microtus spp.) occupy herbaceous and shrubby meadows. Red and Douglas's squirrels are largely restricted to coniferous forests in cone-producing stages, especially late-successional stages, though red squirrels may occur in deciduous forests in the eastern United States. Snowshoe hares generally prefer dense coniferous forest, dense early-seral shrubs, and swamps. Yellow-cheeked voles, important prey in Alaska, are variously reported to have wide habitat tolerances, be restricted to postfire seres, or be associated with lightly burned forest (review by [28]). Population dynamics of prey species may influence prey selection [9,131,151,169]. For more information on habitat associations of potential American marten prey, see the following FEIS reviews: snowshoe hare, red squirrel, northern red-backed vole, meadow vole, and deer mouse.
American marten diet may shift seasonally [6,16,29,58,96,111,115,148,152,181,190] or annually [29,74,115,131,151]. In general, diet is more diverse in summer than winter, with summer diets containing more fruit, other vegetation, and insects. Diet is generally more diverse in the eastern and southern parts of American marten's distribution compared to the western part (review by [136]), though there is high diversity in the Pacific states. American marten exhibit the least diet diversity in the subarctic, though diversity may also be low in areas where the diet is dominated by large prey species (e.g., snowshoe hares or red squirrels) (review by [112]).
American marten may be important seed dispersers; seeds generally pass through the animal intact, and seeds are likely germinable [183]. One study from Chichagof Island, southeast Alaska, found that Alaska blueberry (Vaccinium alaskensis) and ovalleaf huckleberry (V. ovalifolium) seeds had higher germination rates after passing through the gut of American marten compared to seeds that dropped from the parent plant. Analyses of American marten movement and seed passage rates suggested that American marten could disperse seeds long distances; 54% of the distances analyzed were >0.3 mile (0.5 km) [83].
American marten foraging is often associated with woody debris [1,23,30,45,76,133,139,148,149,178], clumps of small trees [45,76,110,139], or the bases of large trees [139,148], because these structure often offer subnivean access [1,23,30,45,76,139,142,148,149,178] or are preferred microhabitats of favored prey species [1,40,110,149]. Subnivean hunting may be more common than surface hunting in winter [30,37,76]. In Grand Teton National Park, evidence of successful above-snow hunting was limited to one observation; 77% of 75 foraging investigations involved American marten descending to subnivean levels, with access typically gained via a cavity in a the snow formed below a partially fallen tree [37].
In southeastern Manitoba, foraging individuals often stopped or circled the roots of fallen trees, logs, coverts of young conifers, or the snow-laden branches of larger trees. American marten stopped 2.2 times/km, dug holes in the snow cover 1.0 time/km, and climbed 1 tree/10 km of trail while foraging [139,142]. In Wyoming, prey were frequently captured in association with large (diameter >15 inches (38 cm)) dead, fallen trees protruding out of the snow. American marten would follow downed trees below the snow's surface to extensive snow-free galleries formed by snow-covered vegetation and fallen trees near ground level [40].
In western Montana, American marten traveled a zigzag course that covered all down logs and windfalls in a large area and ultimately covered "every inch of an area one-tenth to one-fifth acre in size." In areas without downed logs, such as small openings and brushy swamps, individuals tunneled and dug through the snow every few inches [77]. In northeastern California, foraging American marten followed well-traveled routes that appeared to be nonrandom. Their travel pattern while hunting was a weaving or zigzag pattern that investigated all structures (e.g., logs, stumps, tree bases) within a given area [152]. In Grand Teton National Park, most investigation sites (83%) were below the snow surface, and 75% of the investigations were in areas that had >25% canopy cover. Subnivean investigations were usually under forest cover (89% of observations), with the rest occurring in an ecotone between forest and meadow. Entry below the snow surface was usually via a cavity in the snow formed by a fallen tree or sapling. Most sites (88.4%) were associated with fallen trees or saplings, and movement under the snow appeared to be within a network of fallen trees [76].
Several studies report that American marten prefer to hunt in areas with canopy cover and avoid hunting in open areas lacking cover [30,53,73,74,86,94,96,152,159]. In the northern Sierra Nevada, American marten preferred stands with 40% to 60% canopy closure at foraging sites and avoided stands with <30% canopy closure [159]. In Grand Teton National Park, mean canopy cover at foraging sites was 28.9%, with 75% of foraging investigations in areas that had >25% canopy cover [76]. Foraging in open areas has been documented in some areas. In western Montana, American marten hunted in small grassy openings within the forest [181]. In southeastern Manitoba, American marten sometimes hunted in moderately open black spruce-tamarack bogs up to 650 feet (200 m) wide in winter [139,142]. American marten use of open areas is often associated with a specific food resource or with adequate cover nearby. Vernam [178] suggested that American marten may use open areas regenerating after fire to forage on abundant summer berry crops. In northeastern California, logged areas were avoided in winter but used for foraging in summer if they were adjacent to dense stands of intact forest, contained slash, and had some canopy cover [152]. In logged areas in northern Maine, hunting activity was associated with uncut and partially cut stands and not with regenerating clearcuts [162].
Several studies suggest that American marten forage in edge habitat between forested and open areas [29,76,77,86,152,159,181]. In Montana, American marten foraged along edges between regenerating and mature lodgepole pine forest [77] and between large grassy meadows and forest [181]. In Grand Teton National Park, 11% of subnivean foraging investigations occurred in an ecotone between forest and meadow [76]. In southern British Columbia, American marten activity was concentrated in forests adjacent to openings creating by logging [86]. In south-central Alaska, American marten foraged in black spruce woodlands, particularly where this cover type interfaced with other forest types and sedge (Carex spp.) meadows [29]. In the northern Sierra Nevada, American marten hunted primarily beneath dense forest canopy near meadow edges or in riparian lodgepole pine forests with lush herbaceous cover [159].
Not all reports indicate that edges provide suitable foraging habitat for American marten. Winter travel patterns of foraging American marten in Idaho and Wyoming were more linear along edges between intact forest and clearcuts than in the forest interior, suggesting that edge habitat did not provide suitable foraging opportunities in the study areas [81].
Other features associated with American marten foraging include riparian areas [23,86,152,159,178], squirrel middens [149,159], and garbage dumps [152]. American marten in central British Columbia avoided wetlands and cover types that were xeric or in young seral stages while foraging in winter [106].
Denning sites provide protection from predators, inclement weather, and thermal stress (reviews by [18,28]).
Denning structures: American marten use a variety of structures for natal and maternal denning. Natal den structures include the cavities of live trees [18], snags [18,37,76,147,182], logs [18,76,147], stumps, woody debris piles [6], root wads [6,18], red squirrel middens [18], and rock piles [18,147]. In southern Wyoming, 3 natal dens were in snags averaging 26 inches (66 cm) DBH. In northeastern Oregon most tree cavity natal dens were in grand fir (84%), with 30% of the cavity trees alive. Trees averaged 33 inches (83 cm) DBH and were 75 feet (23 m) tall. Most of the hollow logs used as dens were grand fir, averaging 79 feet (24 m) long and 29 inches (73 cm) in diameter at the largest end. All logs had hollow chambers. Those chambers that could be measured averaged 8 to 10 inches (20-25 cm) in diameter inside. Underground natal dens were in rocky areas, under root wads, or under red squirrel middens. Natal dens were described as more secure than resting sites; they were dry, insulated, and inaccessible to predators other than other American marten [18]. In Grand Teton National Park, "nesting" sites were in hollow narrowleaf cottonwoods (Populus angustifolia) (7 standing and 1 fallen). The cavity at one nesting site was 33 feet (10 m) above the ground, and the entrance hole was 7 inches (18 cm) in diameter. Den height in standing trees ranged from 10 to 33 feet (3-10 m) above the ground. Mean DBH of 7 denning trees was 31 inches (79 cm) [76].
Maternal den structures include the branches, cavities or broken tops of live trees [89,106,147,154,187,188], snags [89,147,154], rock piles [32,58], logs [58,147,187,188], witch's brooms [106], and red squirrel nests or middens [147]. Five maternal dens in south-central Oregon were in large live or dead standing trees >29 inches (73 cm) DBH [89]. In northern Wisconsin, 6 of 7 maternal dens were in standing trees >20 inches (50 cm) DBH; no underground structures were used, and no association with coarse woody debris was found [63]. In northwestern Maine, 5 of 6 maternal dens were in hollow northern whitecedar logs or in mature northern whitecedar trees (DBH ranging from 20 to 30 inches (40-70 cm)); the remaining den was in a mature sugar maple [187,188]. In southern Wyoming, the mean diameter of 17 log maternal dens was 21 inches (53 cm), and 26 maternal dens were in snags averaging 22 inches (55 cm) DBH [147].
Structures (% of total) used as natal and maternal dens of female American marten in southern Wyoming. Adapted from [147]. Structure Natal dens (n=18) Maternal dens (n=97) Log 6 18 Snag 17 27 Live tree 0 2 Rock 11 31 Red squirrel nest 0 4 Artificial log* 11 4 Red squirrel midden 56 12 Other** 0 3 *Logs from old cabins or slash piles.Use of denning structures may be influenced by availability. A study comparing denning sites in Oregon and Washington reported that structures varied by study area; females chose to den more often in coarse woody debris and slash in Oregon and in live trees and snags in Washington, which the authors attributed to availability. Trees used for denning were larger than what was generally available, with 90% and 76% of denning trees >20 inches (50 cm) DBH in Washington and Oregon, respectively [143].
Structures used by American marten for maternal denning in Oregon and Washington (% of total in parentheses) [143] Structure Oregon Washington Live tree 6 (19) 14 (54) Snag 5 (16) 8 (31) Single log- bole 10 (32) 1 (4) Logging slash 9 (29) 2 (8) Rock 0 1(4) Animal burrow 1 (3) 0 Total 31 26Denning habitat characteristics: Few studies describe in detail the habitat characteristics at American marten den sites, likely because few studies locate enough dens to make associations clear. In southern Wyoming, where researchers identified 18 natal dens and 97 maternity dens, structural characteristics associated with late-successional forests were important for den sites selected by females. For maternal dens, predictive models identified the number of red squirrel middens as the most important selection variable, followed by number of snags 10 to 15 inches (20-40 cm) DBH, number of snags ≥16 inches (41 cm) DBH, and number of hard logs ≥16 inches (41 cm) in diameter. For natal dens, number of middens, number of Engelmann spruce and subalpine fir >10 inches (20 cm) DBH, and number of hard logs ≥16 inches (41 cm) in diameter were the most important selection variables. Canopy cover was not significantly different at den sites compared to random sites, averaging 67.4% at natal dens, 58.2% at maternal dens, and 58.2% at random sites. The authors suggest that female American marten may be more selective in choosing natal dens than maternal dens, though this hypothesis was not tested [147]. On Vancouver Island, British Columbia, 7 natal dens were found in 30- to 40-year-old second-growth forest [6]. In the Northwest Territories, one female denned and produced young within an area burned 21 years previously [103].
American marten select rest sites based on their potential for thermal cover, protection from predators, and subnivean access in winter (review by [28]).
Rest site structures: American marten use a variety of structures for resting, including live tree platforms [18,23,53,154,176], canopies [8,63,162,182], or cavities [18,23,53], snags [8,30,43,53,89,106,111,152,154,176], witch's broom structures resulting from dwarf mistletoe (Arceuthobium spp.) or fungal infection [18,23,30,37,125,182,187,188], red squirrel nests [23,24,43], red or Douglas's squirrel (T. douglasii) middens [8,24,53,139,143,178], logs [8,25,43,63,111,113,154,162,176,182], stumps [25,63,106,111,113,143,162], slash [18,30,53,63,89,143,152,154] or log [23,37,152] piles, tree root masses [30,37,58,63,89,106,139,143], shrubs [8,154], underground burrows [8,18,24,36,63,143,176], rock or boulder piles [25,37,43,53,58,63,143,154,176,182], roadside debris [143], and human structures [74,143]. Resting site structure varies by season, with higher use of arboreal structures in summer and groundlevel, subnivean structures in winter [18,23,36,37,63,111,162].
In northeastern Oregon, tree platforms were the most common resting site, and 77% of platforms were sheltered by 100% canopy cover. Type of resting site structure varied by tree species, with most platforms in Engelmann spruce and subalpine fir and most cavities in grand fir and western larch. Most hollow logs were also grand fir and western larch. Most (67%) of the cavity trees were dead. Rest site structure varied seasonally. In summer, most resting sites were tree platforms. In winter, most resting sites were located under the snow and were associated with horizontal structures, usually logs or slash piles. At least 75% of the subnivean resting sites had evidence of red squirrel middens. Use of cavities as resting sites peaked in April and from November to December [18].
Structures used as resting sites by American marten in northeastern Oregon over 5 years (adapted from [18]) Structure Percent of total resting sites (n=1,184) Tree platform* 43 Tree cavity 23 Subnivean 23 Hollow log 6 Underground 3 Slash pile 1 *Tree platforms include horizontal branches and/or structures associated with broom rust, dwarf mistletoe, or clumps of lichen (Bryoria spp.).In northwestern Montana, DBH of live and dead trees used as resting sites for American marten ranged from 2 to 28 inches (5-71 cm). Total canopy cover ranged from 17% to 82% [23]. Data from northeastern Oregon also show that trees with a wide range of characteristics were used as resting sites [18].
Average tree characteristics (SD) of resting sites used by American marten in northeastern Oregon (adapted from [18]) Characteristic Tree platformsSelection of resting site structure may be influenced by availability. A study comparing resting sites in the eastern Cascade Range of central Oregon to the western Cascade Range of Washington reported that structures varied by study area, with slash piles used most often in Oregon and live trees used most often in Washington. Slash piles were 4 times more abundant in Oregon than in Washington [143].
American marten often reuse resting sites [24,25,37,53,111,113,162,182]. In southeastern Wyoming, subnivean resting sites with deep snow were likely to be reused, particularly when temperatures were low. One resting site was reused 19 times, and reused sites were sometimes reused by different individuals, though never concurrently [182]. In California, 10% of resting structures were reused up to 5 times [111], while spring resting structures in western Montana were used 1 to 6 times [53]. Males in northwestern Maine did not reuse summer tree canopy resting sites [187,188].
Habitat features at rest sites: One review reports that habitat features are inconsistent at resting sites [27]. In coastal northwestern California, summer and fall resting locations had high tree canopy closure (76%), dense shrub cover, and abundant dead woody structures. At the stand level, resting sites occurred in late-mature or old-growth stands, with old-growth stands used more than expected based on their availability (P<0.0001). Selection for early-seral stands was either neutral or negative (P<0.0001) [154]. In northern Maine, summer rest site selection decreased with increasing canopy cover and understory foliage <1.5 feet (0.5 m). Increases in coniferous stems (<3.0 inches (7.6 cm) DBH) were associated with increased selection of winter resting sites, which the authors suggested offered subnivean access points and facilitated subnivean travel. The distribution of resting sites in coniferous, deciduous, or mixed forests did not vary seasonally, which may have been because structures for resting were abundant throughout the study area [36].
American marten resting sites have been associated with abundant dead wood [25,53,63,154,182] or snags [176], late-seral stage [24,63,154,182], mesic sites [53], riparian areas [25,143,154], or high overhead cover [24,73,143,154,159,182]. However, a preference for high canopy cover was not found at resting sites on the Kenai Peninsula [8] or in northern Maine [36]. Selection for aspect is not consistent across geographic areas, which may relate to local forest cover types associated with specific aspects; 74% of resting sites in northwestern California were on north aspects [154], while most in south-central Alaska were on southerly aspects [24]. Selection for specific local cover types was observed in northern Wisconsin [63], southeastern Wyoming [25,182], western Montana [53], and California [159], though preferences were often linked to the structural attributes occurring in the preferred cover type [25,53,182]. In interior Alaska, male American marten selected burned, open conifer-wet meadow and white spruce forest for resting in summer. Females were observed more often resting in unburned white spruce, black spruce, and mixed-wood (white spruce, paper birch, and balsam poplar) stands, but also rested in burned white spruce forest [178]. (See Wildfire Case Study 1 for more information on this study).
Two studies suggest that American marten avoid logged stands when choosing rest sites. Of 43 winter resting sites in industrial forests in northern Maine, 2 were in regenerating coniferous clearcuts, 18 were in uncut coniferous stands, 12 were in partially cut coniferous-deciduous stands, and 11 were along edges between clearcuts and residual stands. Of 27 summer resting sites, 5 were in regenerating coniferous clearcuts, 13 were in uncut coniferous stands, and 9 were in partially cut coniferous-deciduous stands [162]. In coastal northwestern California, most (65%) summer and fall resting sites were >330 feet (100 m) from logged areas (65%).
American marten travel to maintain territories, forage, and find resting sites (review by [27]). Though they can climb trees, American marten travel mostly on the ground. In winter, tracks in snow follow circuitous routes covering an individual's entire home range. Travel routes stay close to areas with overhead cover, with travel interrupted by frequent investigations where coarse woody debris penetrates the snow surface and provides subnivean access (review by [28]). In northeastern California, movements were variously influenced by cover and topography (e.g., forest-meadow edges, open ridgetop, lakeshores), and negatively influenced by the presence of other American marten [152].
American marten in Alaska.
In southeastern Ontario in the summer, American marten often used fallen logs as runways and appeared to select a travel route that allowed the fullest use of fallen logs [58]. In western Montana, individuals often made repeated use of the same trail [77]. In southwestern Montana logging roads, snowmobile trails, paved highways, and small streams did not impede movement; at least one individual swam the Madison River [43]. In northern Idaho, hiking trails and skid roads were used as travel routes [176].
In general, American marten avoid openings while traveling. In central British Columbia most individuals avoided traveling through xeric cover types, early-seral forests, lakes, or wetlands [106]. However, American marten may use the ecotone between open areas and forests while traveling [23]. If individuals travel through an open area, they may use scattered trees as cover [73,74] or travel in a more direct pattern [8,158]. Open areas that American marten have crossed while traveling include alpine areas, 25-year-old burned areas [155], frozen aquatic areas [53,155], sparse forests [8,155], open sagebrush-grassland [53], meadows [73,74,94,96], and regenerating clearcuts [158].
Travel patterns from 3 areas of the American marten's range are described below.
On the Kenai Peninsula, American marten traveling in winter selected snow and cover types largely in proportion to type availability at the home range scale. At the forest patch scale, movement paths were more winding or twisting through dense forest types compared to open forest types (P<0.001). These movement patterns suggest that individuals were responding to the denser canopy cover, elevated levels of coarse woody debris, and higher density of red squirrel middens present in dense forest types compared to other available vegetation types. Movement patterns may also reflect more foraging opportunities because individuals stop to investigate subnivean access points near coarse woody debris. Travel routes through open or ice-covered areas were significantly more straight than travel routes in vegetated areas (P<0.001) [8].
In Yosemite National Park, winter travel routes occurred in all cover types with no detectible preferences. Topographical features did not restrict travel; streams were crossed repeatedly and rock domes were climbed, though often with the aid of scattered tree cover. Individuals traveled across meadows ≤160 feet (50 m) wide but did not rest or hunt in them. Meadows >160 feet (50 m) wide were crossed using scattered tree cover; the longest open distance crossed was 440 feet (135 m). Individuals also skirted meadows by traveling along the ecotone between meadow and lodgepole pine forest. Microhabitat structure varied between travel routes and random points; travel routes had lower branch height, greater overhead cover, and shorter distance to nearest tree than random points (P<0.01). While moving, individuals preferred areas with 100% overhead cover (P<0.01), but they did not show a preference for dense forest stands. Instead, cover was selected by using a zigzag travel pattern that moved from tree to tree; two-thirds of all travel points were <7 feet (2 m) from a tree. Travel paths were also frequently adjusted to investigate the tracks of other animals [73,74].
In heavily logged forests in western Newfoundland, 74% of American marten winter trails were in forested cover types. The other 26% of tracks were in regenerating clearcuts, even though clearcuts represented 41% of the study area. Sixteen- to 23-year-old clearcuts with balsam fir regeneration >7 feet (2 m) high were not used at all. American marten showed no preference for residual stands >60 acre (25 ha) or undisturbed forest. They demonstrated a strong preference for small residual stands (<60 acre (25 ha)); while small residual stands comprised only 4.2% of the study area, 32.4% of travel routes were in this cover type. Travel patterns varied by cover type; travel routes through clearcuts were generally in a straight line, moving from one residual stand to another. Travel routes in forested habitats often exhibited a zigzag and looped pattern. While traveling, individuals crossed openings 70 to 1,970 feet (20-600 m) wide (87% of crossings were <820 feet (250 m)), though only 21% of pauses occurred in nonforested cover types. Pauses in all cover types were often associated with trees, sticks, or slash protruding above the snowpack or with the tracks of prey species such as the snowshoe hare and red squirrel [157].
Fire has several indirect effects on American marten, including effects on abundance, habitat use, cover, and food. Early researchers perceived fire as having largely negative effects on American marten due to the elimination of habitat ([41,79,139], reviews by [119,179]) or potential decimation of populations ([107], reviews by [22,96,97,137]). One source states that a "forest fire of 100 square miles means the destruction of all martens within that 100 square miles. They cannot escape. The smoke pursues the fugitives and overcomes them. Their food is destroyed in the stricken area" (Seton 1929 as cited in [107]). Although fire may have substantial short-term impacts on American marten populations, it is generally accepted that fire can have long-term benefits for American marten because it creates a mosaic of successional stages offering a variety of resources ([65,94,96], reviews by [23,97,119,179]). The short- and long-term effects of fire on American marten likely depend on several factors, including fire severity (reviews by [94,96,103,161]), fire pattern [103,161], fire size (reviews by [94,96]), time since fire [8,65,94,96,103,139], characteristics of regenerating vegetation [103,161], and local site characteristics ([94,96,161,178], review by [28]).
This section summarizes indirect fire effects on the American marten, presenting a synthesis of broad indirect fire effects as well as 2 detailed wildfire case studies containing habitat descriptions, wildfire descriptions, and specific information on American marten response to wildfire.
Fire may result in a short-term loss of cover (reviews by [23,96,189]) through consumption of woody structures ([46], review by [68]) and/or reduction of canopy cover [46,66,109,123,178]. However, fire may also create structures used for cover; many sources suggest that American marten use of burned areas is related to postfire structural diversity [104], including abundant snags ([65], review by [68]), downed wood ([65,109,123,161,178], review by [28]), and dense herbaceous growth ([109,178], review by [28]). Postfire activity may be concentrated around deadfall, as was documented in southwestern Yukon 25 years after a high-severity wildfire [155]. Similarly, researchers in northwestern Montana observed a juvenile hunting on and under large-diameter logs (>15 inches (40 cm)) in a regenerating lodgepole pine forest approximately 20 years after fire, despite a lack of canopy cover [23]. Downed woody structures or herbaceous vegetation appear to provide adequate cover in place of canopy cover ([23,109,123,178], review by [28]). See Wildfire Case Study 1 for more information on the extensive use of deadfall by American marten 7 to 8 years following wildfire in Alaska.
Local habitat features, such as the presence of riparian areas or a mosaic of burn patterns, may improve the suitability of burned areas for American marten by providing adequate cover. See Wildfire Case Study 1 for information about the importance of riparian areas in providing cover after wildfire. Several studies have documented American marten use of unburned inclusions within burned areas [43,53,109,155,161,178], though one study in central Alaska did not detect selection for unburned inclusions [88,123]. Such inclusions have been used as resting sites [53,139], and interviews with trappers in interior Alaska suggested that unburned inclusions and the edges of burned areas were often centers of American marten activity [161]. In southwestern Yukon, 15 American marten used an area burned by severe wildfire about 25 years previously. The burned area had sparse lodgepole pine, quaking aspen, and willow regeneration, abundant deadfall, and a few small (<25 acre (10 ha)) unburned inclusions. American marten activity was concentrated around deadfall and the unburned inclusions [155]. Ten months after wildfire in southwestern Montana, one individual was located in an unburned 1.2-acre (0.5 ha) island of lodgepole pine forest within the burned area, approximately 0.6 mile (1 km) from contiguous, unburned lodgepole pine forest [53].
Nearby intact forest may also provide important habitat for American marten using burned areas. Intact spruce (Picea spp.) forest adjacent to burned areas was listed as a center of American marten activity by trappers from central Alaska [161]. Also in central Alaska, winter track surveys suggested high American marten use of unburned spruce forest adjacent to an area that burned 8 years previously [84]. In southwestern Yukon, 25 years after a severe wildfire, 13 transplanted, transient American marten spent a few days in a burned area with lodgepole pine, quaking aspen, and willow, but returned to unburned white spruce forest [155]. The ecotone between burned and unburned areas has been described as excellent foraging habitat for American marten ([91], review by [189]), offering both cover and access to prey items. The proximity of intact forest may also impact the ability of American marten to colonize burned areas by providing a source population [123].
American marten often use the edges of burned areas ([88,91,161], review by [189]) but also use or travel through the interior of burned areas [53,103,109,155]. In southwestern Yukon, 25 years after a severe wildfire, 13 transplanted, transient American marten moved ≥10 miles (20 km) into the burned area at times [155].
American marten consume a wide variety of foods throughout their range, preferring certain food items in some areas and not others. Different prey species also have variable habitat needs, all of which might be impacted differently by fire or other ecological factors [88] (see Food Habits). A generalist diet and variability in prey habitat preferences makes it difficult to make broad generalizations about the impact of fire on American marten food resources. Numerous sources suggest that fire alters American marten food availability, largely through changes in diversity and/or abundance ([8,91,94,96,109,123,150,155,161,178], reviews by [68,189]). Some sources suggest that food resources may be reduced immediately after fire [23,96], while reviews suggests that certain food resources may be more available or abundant after fire [65,68,119,189], at least during the snow-free seasons [22,179]. Trappers in central Alaska attributed American marten presence in burned areas to an increase in microtine (Microtinae) rodents, the presence of berries, and the availability of downed timber available after fire [161]. In interior Alaska, small mammal species diversity was greater in black spruce forest burned by wildfire 7 to 8 years previously compared to unburned areas, and small mammal abundance in burned areas was equal to or surpassed that in unburned areas. Meadow voles (Microtus spp.), considered the preferred prey in this study area, were more common within the burned area, while red-backed voles (Myodes spp.) were more common outside the burned area [109]. See Wildfire Case Study 1 for more information on this study. Similar results were documented in a different study area in interior Alaska; American marten abundance was highest in an early postfire sere (postfire years 6-9) containing a mixture of birch (Betula spp.) and black spruce regeneration. This postfire sere had the highest abundance of yellow-cheeked voles, a preferred food item. This postfire sere also contained more diverse prey items and lacked the fluctuations in northern red-backed vole (M. rutilus) populations observed in other postfire seres [88]. See Wildfire Case Study 2 for more information on this study.
In east-central Alaska, the abundance and diversity of potential American marten small mammal prey differed between approximately 24-year-old quaking aspen stands regenerating from a severe fire and unburned black and white spruce forest. Northern red-backed voles were ubiquitous across cover types, while yellow-cheeked voles were most abundant in the burned habitat. Both species were potential prey items, though their relative value to American marten in this study area was not discussed. Over the 3 years of study, microtine rodent populations declined in burned forests and showed no clear trend in unburned forest. The author did not attribute small mammal population declines in burned areas to postfire conditions or any other factor. The study area did experience unusually cold spring temperatures [150].
Relative abundance of small mammals captured during August 1991-1993 in areas severely burned approximately 24 years previously and unburned areas, Yukon-Charley Rivers National Preserve, Alaska [150] Small mammal species 1991 1992 1993 Burned Unburned Burned Unburned Burned Unburned All microtine rodents 24.7 7.3 11.9 11.5 5.6 2.5 Northern red-backed vole 13.9 6.3 7.8 10.8 4.9 2.2 Yellow-cheeked vole 10.8 0.9 4.1 0.5 0.7 0.2 Shrews (Soricidae) 6.8 4.2 1.5 0.6 7.1 3.9The ability of burned areas to provide preferred food items may be related to several factors, including those related to fire (e.g., severity, size, time since fire) or local site characteristics (e.g., moisture regime). On the Kenai Peninsula, black spruce forest burned 59 years previously had sufficient cover to support American marten prey. However, a young forest of northern hardwoods and immature conifer saplings that burned 37 years previously did not [8]. Approximately 12 years after wildfire on mesic sites in north-central Idaho, one plot that experienced low-severity surface fire supported American marten prey, while another plot that experienced high-severity fire did not. Microtine rodents, occurring in 71% of summer-fall scats, were abundant in areas burned 40 to 60 years previously or in mesic sites within meadows. Areas burned 10 to 15 years previously and exhibiting xeric conditions supported high numbers of deer mice, which were not a favored prey item, and supported few microtine rodents [94,96].
While most studies examining American marten food items and fire concentrate on small mammals, it is also likely that fire affects the abundance and availability of plant species used as forage, particularly berries. American marten summer diets in north-central Idaho contained high amounts of fruits, insects, and ground squirrels, all of which were available in open meadows and burned areas [94,96]. Seven to 8 years after wildfire in Alaska, Vernam [178] noted that berry production was highest in extensive areas of burned open meadows and black spruce forest, which may have caused American marten to expand their home range into burned areas in the summer. See Wildfire Case Study 1 for more information on this study.
For more information on fire effects on American marten food items, see the following FEIS reviews: snowshoe hare, red squirrel, northern red-backed vole, meadow vole, deer mouse, Alaska blueberry, and ovalleaf huckleberry.
Fire may indirectly affect American marten abundance, home range characteristics and use, dispersal, and mortality.
Fire effects and abundance: Fire may temporarily displace American marten, as was suggested following the 1988 Yellowstone fires [67]. American marten have been detected immediately following fire [139] and in areas regenerating from fire over a wide range of stand ages. In Sequoia-Kings Canyon National Park, several American marten were detected from May to mid-October at sites with a recent history of fire (prescribed fire, wildfire from natural or accidental ignition). There were >10 American marten detections in areas burned in the past 2 to 30 years [68]. Interviews from trappers in interior Alaska suggested that there was no consistent numerical response of American marten to fire; some trappers observed higher American marten abundance in burned areas, while others observed lower abundance or complete absence in burned areas [88,161]. Trappers also noted that in areas with established American marten populations, extensive use of burned areas by American marten could occur as soon as 1 to 3 years after fire. High populations often developed within 3 to 5 years in some areas, though populations in other areas did not recover for 6 to 10 years [161]. Two juvenile American marten were found only in unburned bog habitats immediately after a 160,000-acre (65,000 ha) mixed-severity fire in a black spruce forest in southeastern Manitoba. Six months after the fire, one individual spent 86.0% of its time on burnt coniferous ridges and only 6.7% of its time in unburned bogs [139].
It is difficult to determine how American marten abundance changes over time in burned areas, because no studies to date (2010) had documented long-term trends from a single area. While a few studies present data from burned areas of different ages, the results are not comparable due to different times since fire, American marten survey methods, fire characteristics, and local differences in plant community response to fire. In burned boreal forest (white spruce, black spruce, paper birch, quaking aspen, balsam poplar) of interior Alaska, American marten track densities were higher in an area burned 6 years previously compared to an area burned 35 years previously [65]. One study found American marten abundance increased with time since fire. On the Kenai Peninsula, American marten were detected 4 times as frequently in forests regenerating from a wildfire 59 years previously compared to forests regenerating from a wildfire 37 years previously. The older forest—comprised of mature black spruce—contained "ample cover and structure for supporting marten and their prey", while the younger forest—containing a mixture of northern hardwood species and immature coniferous saplings—lacked appropriate cover, structure, and potentially prey habitat [8].
Other than the observations by trappers that some areas may experience higher American marten abundance following fire [161], only 1 source suggests that American marten numbers may increase following fire. A review of the effects of fire on furbearers reports that 15 to 18 years after a "large" forest fire in Yukon, 8 American marten were harvested in a burned area where none had been harvested previously [22].
A few studies report low detection rates or use of burned areas by American marten. In Ontario, American marten were essentially absent from "recently burned-over areas" of regenerating mixed or pure stands of quaking aspen and/or paper birch. The burned areas offered little cover and few denning options in trees [46]. In northwestern Montana, researchers had limited live trapping success in burned areas; trapping success was highest along the edge between a mature mixed-conifer forest and young lodgepole pine forest [77]. In southwestern Montana, American marten exhibited low use of areas burned 1 to 2 years earlier [53]. In eastern Newfoundland, black spruce-balsam fir forests that had burned approximately 15 to 20 years earlier had <25% canopy cover; American marten used these forests less than expected based on availability, while mature black spruce-balsam fir forests were used more than expected (P<0.05) [66]. In southeastern Labrador, American marten used black spruce-balsam fir forest burned 42 years previously in proportion to its availability [156].
One study documented higher American marten abundance in burned areas than in unburned areas and in a younger burned area than in an older burned area. American marten relative abundance was studied in burned and unburned boreal forests in interior Alaska by sampling winter tracks. Two burned areas of different ages were located in the study area: one 282,000-acre (114,000 ha) area that burned approximately 6 years prior to the study (younger burned area) and a 2 million-acre (829,000-ha) area that burned 35 years prior to the study (older burned area). At the time of sampling, the younger burned area was in the moss-herb/tall shrub-sapling stage of succession, with grasses, fireweed (Chamerion angustifolium), paper birch, quaking aspen, and balsam poplar dominating. The site was littered with fallen trees, contained abundant standing dead spruce, and had many inclusions of live, mature spruce and deciduous trees. The older burned area was in the dense tree stage of forest succession, with mosaics of pure and mixed stands of white spruce, quaking aspen, paper birch, balsam poplar, and willow. Across the entire study area, including both burned and unburned forest, some of the highest American marten track densities were found near or inside the younger burned area, concentrated around the perimeter. American marten track densities were higher in the younger burned area compared to the older burned area. The authors attributed this pattern to the high levels of deadfall and presumably abundant small mammal populations in the younger burned area [65].
Average density of American marten tracks inside and outside of the perimeter of an area burned 6 years previously in interior Alaska. Adapted from [65]. Average tracks/km (range) 1985 (n=13) 1986 (n=14) Inside 1.33 (0.31-3.64)* 2.11 (0.76-4.16)** Outside 0.90 (0.21-1.75)* 1.16 (0.12-2.03)*** *Values with different numbers of * are significantly different (P<0.1).One author suggests that wildfire in south-central Alaska may have prevented American marten from dispersing through several narrow valleys from the eastern to the western side of the Kenai Peninsula, resulting in low overall abundance [5].
Fire effects and home range: American marten have large home ranges, and though individuals may exhibit high fidelity to an established home range, they often use core areas of their home range, may shift their home range boundaries, or may make major movements within home ranges on a routine basis. American marten are also capable of long-distance dispersal (see Home range for more information). These characteristics of home ranges, patterns of use, and mobility likely help minimize the negative effects of fire on American marten.
One study from northwestern Montana reported that home range boundaries seemed to coincide with the edge of large open meadows and burned areas [78]. Several studies have documented American marten with home ranges largely or entirely within burned areas [88,103,109,178]. Twenty-one years after a taiga wildfire in the Northwest Territories, 11 of 12 adult American marten had home ranges that incorporated 3% to 92% of the burned area (x=53%). Home ranges of 1 adult and 1 juvenile were entirely within the burned area. The authors concluded that the majority of individuals used the burned area extensively but not intensively. They also observed that home range size was large in this area compared to other studies [103]. See Wildfire Case Study 1 and Wildfire Case Study 2 for additional examples of American marten predominantly using burned areas.
Though it seems likely that American marten home ranges may shift in response to postfire conditions, only one study has documented home range use before and after fire. Immediately after a 160,000-acre (65,000 ha) mixed-severity fire in boreal forest of southeastern Manitoba, one juvenile female increased her use of black spruce-tamarack bogs in the snow-free season. While home range size did not change after the fire, black spruce-tamarack bogs comprised 32.9% of her home range prior to the fire, and 35.2% after the fire. Bogs were the only cover type that did not burn in the fire [139,140].
Fire effects and dispersal: Though some studies have documented dispersal through or from burned areas [88,103,109,139,178], it is not clear that postfire conditions caused the dispersal. Immediately following a 160,000-acre (65,000 ha) mixed-severity wildfire in the boreal forests of southeastern Manitoba, a juvenile male was located for 2 weeks in unburned black spruce-tamarack bogs before radio contact was lost. This individual was eventually killed by a trapper 38 miles (61 km) away. The author suspected that dispersal was caused by postfire conditions, but the juvenile may not have established a territory prior to the fire, making dispersal inevitable [139]. See Wildfire Case Study 2 for additional examples of American marten dispersing from a burned area.
Fire effects and mortality: It is not clear whether American marten mortality rates increase following fire. In Alaska, researchers suggested that mortality may be higher for American marten with home ranges within burned areas compared to those that have at least part of their home range in unburned habitat, though the authors admitted that this assertion was based on a small sample size and circumstantial evidence [109].
Use of burned areas for specific life history activities: American marten have been documented using burned areas for foraging and hunting, resting, traveling, and reproduction.
Several studies have documented American marten using burned areas for hunting or foraging [23,88,91,109,123,161,178] (see Wildfire Case Study 1 and Wildfire Case Study 2 ). Biologists with the Alaska Department of Fish and Game observed American marten foraging along the edges of recently burned forest [91]. Approximately 20 years after fire in northwest Montana, a juvenile American marten was observed hunting on and under large-diameter logs (>15 inches (40 cm)) in open areas along a creek in regenerating lodgepole pine forest [23]. See Fire effects on food for more information.
A few studies have documented American marten resting in burned areas [109,139,178]. In the summer following a 160,000-acre (65,000 ha) mixed-severity wildfire in the boreal forests of southeastern Manitoba, one resting site was located on the edge of an unburned black spruce-tamarack bog and was formed by the roots of a fallen jack pine [139]. See Wildfire Case Study 1 for more information.
American marten may travel through burned areas ([43,53], review by [28]). In southwestern Montana, radio-collared American marten crossed through extensive areas burned 1 to 2 years previously but were never located within the areas via radio-telemetry or snow tracking [53]. One American marten in Montana moved 7 miles (11 km) in 1 day, traveling through large areas of coniferous forest burned 4 years previously [43]. In Alaska, American marten routinely traveled through and within black spruce forest burned by wildfire 7 to 8 years previously [109]. See Wildfire Case Study 1 for more information.
One study has documented American marten reproduction in a burned area. In the Northwest Territories, one female's home range contained unburned black spruce taiga and black spruce taiga regenerating 21 years after a high-severity wildfire. She denned in the burned area and produced young [103]. In central Alaska, biologists found low ovulation rates, high population turnover, high dispersal frequency, and a juvenile-biased age structure in early postfire seres, suggesting that recently burned areas lacked the conditions necessary for successful reproduction [123]. See Wildfire Case Study 2 for more information on this study.
Description: The American marten is a long, slender-bodied weasel about the size of a mink with relatively large rounded ears, short limbs, and a bushy tail.
American marten have a roughly triangular head and sharp nose. Their long, silky fur ranges in color from pale yellowish buff to tawny brown to almost black. Their head is usually lighter than the rest of their body, while the tail and legs are darker. American marten usually have a characteristic throat and chest bib ranging in color from pale straw to vivid orange (review by [38]). Sexual dimorphism is pronounced, with males averaging about 15% larger than females in length and as much as 65% larger in body weight (review by [38]). Body length ranges from 1.5 to 2.2 feet (0.5-0.7 m). Adult weight ranges from 1.1 to 3.1 pounds (0.5-1.4 kg) and varies by age and location. Other than size, sexes are similar in appearance (review by [28]).American marten in southwest Montana.
American marten have limited body-fat reserves, experience high mass-specific heat loss, and have a limited fasting endurance. In winter, individuals may go into shallow torpor daily to reduce heat loss (review by [136]).
Breeding: American marten reach sexual maturity by 1 year of age, but effective breeding may not occur before 2 years of age (review by [136]). In captivity, 15-year-old females bred successfully (reviews by [38,166]). In the wild, 12-year-old females were reproductive [166].
Adult American marten are generally solitary except during the breeding season (review by [38]). They are polygamous, and females may have multiple periods of heat (review by [166]). Females enter estrus in July or August (review by [136]), with courtship lasting about 15 days (review by [38]). Embryonic implantation is delayed until late winter, with active gestation lasting approximately a month. Females give birth in late March or April to a litter ranging from 1 to 5 kits (review by [136]). Annual reproductive output is low according to predictions based on body size. Fecundity varies by age and year and may be related to food abundance (review by [28]). In northeastern Oregon, low population reproductive rates were associated with high levels of predation on females prior to weaning kits [20].
Denning behavior: Females use dens to give birth and to shelter kits. Dens are classified as either natal dens, where parturition takes place, or maternal dens, where females move their kits after birth (review by [28]). American marten females use a variety of structures for natal and maternal denning, including the branches, cavities or broken tops of live trees [18,89,106,147,154,187,188], snags [18,37,76,89,147,154,182], stumps [6], logs [18,58,76,147,187,188], woody debris piles [6], witch's brooms [106], rock piles [18,32,58,147], and red squirrel (Tamiasciurus hudsonicus) nests or middens [18,147]. See Denning for more information on denning structures and habitats associated with denning.
Females prepare a natal den by lining a cavity with grass, moss, and leaves (review by ([165]). In southern Wyoming, females moved kits frequently to new maternal dens once kits were >13 weeks old [82]. In another study in southern Wyoming, the average number of maternal dens per individual was 10.8, ranging from 5 to 24 [147]. In northwestern Maine, females moved kits from tree-cavity natal dens to groundlevel log maternal dens when kits were 7 to 8 weeks old, then moved kits back into large tree dens when they gained coordination at 12 to15 weeks old [187,188]. In southern Wyoming, females did not move kits from aboveground to ground structures between natal and maternal denning; many natal dens were in ground structures [147].
In southern Wyoming, most females spent a majority of their time (>50%) attending dens in both preweaning and weaning periods, with less time spent at dens as kits aged. Females were often away from dens from dusk to midnight [82]. Paternal care has not been documented (review by [28]).
Development and dispersal of young: Weaning occurs at 42 days. Young emerge from dens at about 50 days but may be moved by their mother before this (review by [28]). In northwestern Maine, kits were active but poorly coordinated at 7 to 8 weeks, gaining coordination by 12 to15 weeks [187,188]. Young reach adult body weight around 3 months (review by [136]).
Kits generally stay in the company of their mother through the end of their first summer, and most disperse in the fall (review by [28]). The timing of juvenile dispersal is not consistent throughout American marten's distribution, ranging from early August to October (review by [28]). In south-central Yukon, young-of-the-year dispersed from mid-July to mid-September, coinciding with the onset of female estrus [3]. Observations from Oregon [19] and Yukon [3] suggest that juveniles may disperse in early spring. Of 9 juvenile American marten that dispersed in spring in northeastern Oregon, 3 dispersed a mean of 20.7 miles (33.3 km) (range: 17.4-26.8 miles (28.0-43.2 km)) and established home ranges outside of the study area. Three were killed after dispersing distances ranging from 5.3 to 14.6 miles (8.6-23.6 km), and 3 dispersed a mean of 5.0 miles (8.1 km) (range: 3.7-6.0 miles (6.0-9.6 km)) but returned and established home ranges in the area of their original capture. Spring dispersal ended between June and early August, after which individuals remained in the same area and established a home range [19].
Daily activity patterns: American marten activity patterns vary by region (review by ([165]), though in general, activity is greater in summer than in winter ([18], reviews by [38,136]). American marten may be active as much as 60% of the day in summer but as little as 16% of the day in winter (review by [136]). In north-central Ontario individuals were active about 10 to 16 hours a day in all seasons except late winter, when activity was reduced to about 5 hours a day [169,173]. In south-central Alaska, American marten were more active in autumn (66% active) than in late winter and early spring (43% active) [29]. In northeastern California, more time spent was spent traveling and hunting in summer than in winter, suggesting that reduced winter activity may be related to thermal and food stress or may be the result of larger prey consumption and consequent decrease in time spent foraging [190].
American marten may be nocturnal or diurnal. Variability in daily activity patterns has been linked to activity of major prey species ([190], review by ([165]), foraging efficiency [29], gender [30], reducing exposure to extreme temperatures ([29,178], review by [165]), season ([76,190], review by [136]), and timber harvest [169]. In northeastern California, activity in the snow-free season (May-December) was diurnal, while winter activity was largely nocturnal [190]. In Grand Teton National Park, American marten activity peaked at midnight and late morning in spring. In summer, activity peaked at midnight, early morning, and mid-afternoon [76]. In south-central Alaska, American marten were nocturnal in autumn, with strong individual variability in diel activity in late winter. Activity occurred throughout the day in late winter and early spring [29]. In western Newfoundland, American marten were more active at night than during the day in winter; this result contrasts with other studies but may be explained by the generally warmer temperatures of the study region [51].
Daily and seasonal movement: Daily distance traveled may vary by age [150], gender, habitat quality [169], season [76], prey availability, traveling conditions, weather, and physiological condition of the individual [110]. Year-round daily movements in Grand Teton National Park ranged from 0 to 2.83 miles (0-4.57 km), averaging 0.6 mile (0.9 km) (n=88) [76]. In Glacier National Park, Montana, year-round daily movements averaged 0.4 mile (0.6 km), ranging from 0.2 to 1.7 miles (0.1-2.8 km) [23]. One American marten in south-central Alaska repeatedly traveled 7 to 9 miles (11-14 km) overnight to move between 2 areas of home range focal activity [29]. Two individuals in southwestern Montana routinely moved >4 miles (7 km) overnight [43]. One individual in central Idaho moved as much as 9 miles (14 km) a day in winter, but movements were largely confined to a 1,280-acre (518 ha) [110] area. Juvenile American marten in east-central Alaska traveled significantly farther each day than adults (x=1.4 miles (2.2 km) vs. 0.9 mile (1.4 km); P=0.001) [150]. In north-central Ontario, daily linear distance traveled was greater for males than females and for adults in logged than in unlogged forest (P<0.0001) [169].
Studies from Wyoming suggest that immigration and emigration are most likely to occur in the fall [39,40,76], with males more likely to move more than females [40]. American marten may also make smaller seasonal movements. Several studies have documented a seasonal shift in home range [6,29,129] (see Home range for more information). Two studies have documented seasonal migration in elevation. In south-central Alaska individuals moved to higher elevations in spring and to lower elevations in autumn, which the author attributed to food availability [29]. At the Kenai National Wildlife Refuge, south-central Alaska, individuals moved to higher elevations during the snow season, likely seeking the increased thermal protection offered by deep snow [148].
Population structure: American marten populations may contain many transient individuals. Of 85 American marten captured in northwestern Montana, 35% were residents (present in study area for >3 months), 55% were transients (present for <1 week), and 9% were temporary residents (present for >1 week but <3 months) [78]. In Wyoming, less than half of the American marten observed in Grand Teton National Park were considered residents and 33% were considered transients. On the Bridger-Teton National Forest, Wyoming, 67% of the population was considered residents, 7% were temporary residents, and 26% were transients [39].
Population age structure depends heavily on whether or not a population is trapped. Age structure of trapped populations responds mostly to the timing and intensity of harvest (review by [28]). Age structure of populations may also fluctuate in response to prey availability (review by [136]). Over a 3-year study in east-central Alaska, age structure of a trapped population was 49% juvenile (<1 year old), 26% yearling (1-2 years old), and 25% adult (≥ 2 years old) [150].
Population density: Compared to other carnivores, American marten population density is low for their body size. One review reports population densities ranging from 0.4 to 2.5 individuals/km² [28]. Population density may vary annually [60,64] or seasonally [3]. It may be influenced by several factors. Low population densities have been associated with low abundance of prey species ([60,150], reviews by [28,136,165]), environmental stress (e.g., weather conditions) [150], logging ([126,128,158], reviews by [28,165]), and trapping pressure (114, review by ([165]).One study from southern Ontario found no detectible relationship between trapping mortality and changes in American marten density, though it did find some evidence of density-dependent population growth [60].
Home range: Home range size of the American marten is extremely variable, with differences attributable to sex [6,19,26,29,129,132,156,187,188], year [66], geographic area (review by [28]), prey availability ([19,66,80,150], review by [28,165]), cover type, quality or availability ([19,80,126,156,178], review by [28,165]), habitat fragmentation [80], reproductive status [90], resident status [23], predation [19], and population density (18,116, review by ([165]). Home range size does not appear to be related to body size for either sex [156]. Home range size ranged from 0.04 mile² (0.1 km²) in Maine to 6.1 miles² (15.7 km²) in Minnesota for males, and 0.04 mile² (0.1 km²) in Maine to 3.0 miles² (7.7 km²) in Wisconsin for females (review by ([165]). For a review of American marten home range size and variability throughout its range as of 1989, see Buskirk and Lyman [26]. For more recent home range information, see the following sources: Alaska [150], Idaho [176], Maine [129], Michigan [168], Montana [43], Oregon [19], Wisconsin [186], Wyoming [120], British Columbia [6,106,132], Labrador [156], Newfoundland [66], Quebec [64]. Home range estimates are difficult to compare between studies because of different techniques used to obtain locations and/or to calculate areas (review by ([165]).
Males generally exhibit larger home ranges than females [6,19,26,29,129,132,156,187,188], which some authors suggest is due to more specific habitat requirements of females (e.g., denning or prey requirements) that limit their ability to shift home range [129]. However, studies in east-central Alaska [150] and southeastern Quebec [64] did not find male home range to be larger than female. In both studies, 2 females exhibited unusually large home ranges; in one study both individuals were juvenile [150], and in the other study, much of the home range consisted of logged forest [64]. Males and females in northeastern California appeared to have approximately equal home range size [152].
Home range is generally larger in logged than unlogged areas [61,80,126,135,158,172], though all studies supporting this assertion are from New England or eastern Canada. In northern Maine, regenerating clearcuts (3-18 years old) comprised 16% to 50% of the home range of the adults studied [162]. In north-central Ontario, distances between core areas of individual home ranges were greater in logged (<5 to >30 years) than unlogged forest (P<0.001) [173]. In northeastern British Columbia, removal of immature forest cover of 17% of the study area resulted in home range shifts at the individual level but no detectable impact at the population level, though 5 American marten dispersed out of the treated area and 1 died [132]. In southeastern Quebec, most predictive models included an element of human or natural disturbance to explain increases in home range size; home ranges tended to be larger as road density increased or the landscape contained a higher proportion of unlogged stand with a light outbreak of eastern spruce budworm (Choristoneura fumiferana) [64].
In Wyoming, home range size varied with no apparent pattern relative to age, season, or year, including years with timber harvesting [120]. Similarly, home range sizes did not differ when comparing undisturbed to clearcut (100% removal) and selectively cut (40% removal)) habitat in Wyoming, though individuals may have shifted their home range in response to these disturbances [40].
Home ranges are indicated by scent-marking. American marten male pelts often show signs of scarring on the head and shoulders, suggesting intrasexual aggression that may be related to home range maintenance (review by ([165]). Home range overlap is generally minimal or nonexistent between adult males [3,23,29,30,40,76,186] but may occur between males and females [3,23,29,30,40,111], adult males and juveniles [29,148], and between females [30,40,178]. In northeastern Wisconsin a few individual male home ranges overlapped extensively (88% overlap) in winter [186]. In Grand Teton National Park, male home range overlap was small or nonexistent except in the fall [76]. On Vancouver Island, British Columbia, overlap within and between the sexes generally occurred at the periphery of home ranges [6].
Individual American marten tend to exhibit high fidelity to an established home range [19,29,120,129], though observations in Grand Teton National Park suggested that home range boundaries frequently shift [76]. In north-central Maine males tended to show more seasonal and year-round fidelity to home range than females, with some females exhibiting high home range fidelity while others abandoned or shifted home ranges seasonally [129]. In north-central Maine adult males shifted or expanded their home range when bordering males died [129]. In south-central Alaska, one male shifted home range completely, but most others showed small seasonal shifts in concentration areas within an established home range [29]. Seasonal shifts in home range were observed in Alaska [29] and Vancouver Island, British Columbia [6], but not at a different site in Alaska [148].
Observations from Alaska [29], California [113,152], Idaho [110], and Vancouver Island, British Columbia [6], suggest that American marten may concentrate activity within small parts of their home range. In Alaska [148] and on Vancouver Island [6], core use areas shifted seasonally. In northern California, individuals would occupy small areas of their home range for a few weeks, then completely shift activity to a new area [113]. In central Idaho, daily winter movements generally do not extend beyond a 1 mile² (260 ha²) area, though throughout the winter an overall area 12 to 15 miles² (3,100-3,900 ha²) was used [110].
Several authors have reported that home range boundaries appear to coincide with topographical or geographical features. In northeastern California, movements and home range boundaries were influenced by cover, topography (forest-meadow edges, open ridgetop, lakeshores), and other American marten [152]. In south-central Alaska, home range boundaries included creeks and a major river [29]. In an area burned 8 years previously in interior Alaska, home range boundaries coincided with transition areas between riparian and nonriparian habitats [178]. In northwestern Montana, home range boundaries appeared to coincide with the edge of large open meadows and burned areas; the authors suggested that open areas represent a "psychological rather than physical barrier" [78].
Several life history characteristics inhibit American marten population recovery from natural and human-caused population declines. American marten have large spatial requirements for their body size, low population densities, and low reproductive rates (review by [28]). Small litter size and delayed maturity make it difficult for populations to recover from large losses ([76], review by [28]). Several populations in the western United States are known or suspected to be geographically isolated, suggesting they may be more vulnerable to negative consequences of human activities (review by [28]).
American marten populations may be negatively impacted by several anthropogenic and natural disturbances, including habitat loss, timber harvest, trapping, climate change, and insect outbreaks. For a review of the impact of human activities (e.g., trapping, logging, agriculture) on American marten and other mustelids in North America, see Proulx [137].
Habitat loss: Habitat loss due to both anthropogenic and natural disturbance is cited as a major factor in the decline and/or extirpation of some American marten populations (reviews by [10,28,136,168,185,191]). Population fluctuations in the Northeast are largely attributed to changes in forest cover due to logging and subsequent reforestation. Major population declines in California are likely the result of loss of mature forest due to timber harvest (review by [28]).
Timber harvest: Timber harvest is common throughout the range of the American marten. In general, it has a negative effect on American marten; timber harvest removes overhead cover and large-diameter coarse woody debris, and in the case of clearcutting, may convert mesic sites to xeric sites (review by [28]). The structural changes associated with logging reduce protective cover [30] and may also alter the abundance and distribution of prey species ([30,40,61,71,75,169,173], reviews by [28,97]). In north-central Ontario, American marten in uncut areas encountered 2 to 3 times as many prey items and killed up to 119% more prey biomass compared to areas cut anywhere from <5 to >30 years previously (P=0.003) [169,173].
Timber harvest may lead to lower American marten densities [1,30,126,158], larger home ranges [135,158], home range shifts [132], higher natural mortality [135], higher dispersal rates [132,135], greater daily movements, greater distances between core use areas within a home range, and shifts in daily activity patterns [173]. American marten avoided harvested areas in Maine [61,126,127], Wyoming [40,81], Montana [43,53], Idaho [81], Utah [71,75], Oregon [21], California [152,153], Newfoundland [59,157], Quebec [64], Ontario [170], Alberta [138], and British Columbia [86].
In general, American marten make little or no use of clearcuts for several decades following harvest (review by [28]). In Idaho and Wyoming, the clearcuts crossed by American marten were significantly narrower than clearcuts they did not cross (464.2 feet (141.5 m) vs.1,053.5 feet (321.1 m), P<0.001); crossed clearcuts also contained abundant aboveground structures (e.g., standing trees, snags) [81]. Use of harvested areas may be higher where partial or selective harvest methods are used instead of clearcutting ([30,40,61,62,64,158,162], review by [97]); postharvest silvicultural treatments are used [170]; harvested stands are close to intact forest [72,152]; treatments are small ([86], review by [97]); forest regeneration is relatively fast [116,127]; or harvested areas offer benefits like seasonal food items [152,162]. Use of harvested areas may be greater as time since treatment increases [43,61,138].
See the following sources for management recommendations related to timber harvest and American marten habitat: [11,36,72,75,105,127,174].
Trapping: American marten are trapped for their fur in all but a few states and provinces where they occur (review by [136]). In North America, the highest peak trapping year occurred in 1820, when approximately 272,000 American marten were harvested (review by ([165]).
Harvest is a major source of American marten mortality in trapped populations ([135,150] review by [28]) and may account for up to 90% of all deaths in some areas (review by [28]). Overharvesting has contributed to local extirpations [10,168]. Trapping may impact population density, sex ratios ([126], review by ([165]) and age structure (reviews by [28,136]). Several studies suggest that juveniles are more vulnerable to trapping than adults ([4,43,80], review by [10]), and males are more vulnerable than females ([43,80], reviews by [28,189]). American marten are particularly vulnerable to high levels of trapping mortality in industrial forests (review by [136]).
See the following sources for information related to trapping and its impact on American marten populations: Alaska [150,161], Maine [85,90,126,128], Montana [43], Newfoundland [80], Ontario [60], Quebec [135], Yukon [3]. See the following sources for management suggestions related to harvest: [28,137,165,189].
Climate change: Climate change has the potential to significantly impact American marten populations through changes in vegetation, snowpack depth, and climate-related disturbance.
One model simulation investigated the potential impacts of climate change on American marten populations isolated from boreal populations at the southern extension of their range in southeastern Canada and the northeastern United States. The author hypothesized that decreased snowfall resulting from climate change may reduce American marten populations through decreased prey availability and decreased competitive advantage over sympatric carnivores. In modeling exercises correlating regional American marten distribution with vegetation and snowfall, American marten populations experienced greater declines due to climate change (modeled as decreased snowfall; 40% population decline) than to trapping pressure (30% population decline) or logging (16% population decline). Climate change and logging interacted to cause greater predicted decreases in American marten populations (61% population decline). Vulnerability to population decreases and fragmentation varied within the study region, with greater predicted impacts in areas with smaller, isolated, and/or peripheral populations [32].
Climate change may also impact related disturbances (e.g., fire and insect outbreaks) that effect large areas of the landscape; modeling suggests the potential for American marten to decline following large-scale mountain pine beetle (Dendroctonus ponderosae) outbreaks, which may increase with climate change [163]. On the Kenai Peninsula, managers were concerned that climate change could degrade habitat preferred by local American marten populations, including mature forests with closed canopies, complex structure, and a consistent, deep snowpack. As of 2009, the region had already experienced major shifts in landcover composition attributed to climate change, including increased spruce beetle (D. rufipennis) outbreaks, shifting FIRE REGIMES, rising treelines, drying wetlands, and increasing accumulated yearly snow depths. Spruce beetle outbreaks reduced overhead canopy cover and could potentially convert white spruce forest to early-successional hardwood forests. The author suggests that climate change may be responsible for recent shifts in American marten distribution in the region and that future American marten habitat could be limited by large-scale landscape changes resulting from increasing fire frequency and insect outbreaks. "Because of their physiological sensitivity to environmental conditions, American marten represent one of the most proximate, mammalian sentinel species of climate change" [8]. Concern over the impact of vegetational shifts on American marten is also reported from California [92] and the Greater Yellowstone Ecosystem [146]. Changes in snowpack dynamics are also a concern, because lower snowpacks in some areas could decrease the American marten's competitive advantage over fishers [92,99].
Insect outbreaks: Insect outbreaks are a common disturbance process in parts of the range of the American marten. Studies associating American marten with insect outbreaks include reports from Alaska [8,148], Colorado [189], Maine [35,126,187,188], British Columbia [145], and Newfoundland [50]. Insect outbreaks may result in widespread mortality of canopy trees, which in turn leads to more open canopies [35,145,148] and more snags [126,145,148], logs [126,145,148], root masses [126], and shrubs [145,148]. Prey species composition or abundance ([8,189], review by [145]) may also change. It is not clear whether changes resulting from insect outbreaks benefit or harm American marten. Impacts from mountain pine beetle infestations in lodgepole pine forests in British Columbia were predicted to change over time. Short-term impacts (initial infestation to understory recovery in 1-5 years) include reduced security from avian predators and a change in prey type and abundance. Medium-term impacts (20-50 years) include a decline in the abundance of snags and an increase in coarse woody debris, resulting in fewer tree cavities but more structures for ground dens. Longer-term impacts (70-100 years) include the decay of coarse woody debris, which may reduce den sites and limit subnivean access (review by [145]).
On the Kenai Peninsula, biologists suggested that the impacts of beetle outbreaks would not necessarily be negative; impacts might be similar to those of selective harvesting. The landscape following insect outbreaks might be a mixture of islands of dense trees and open areas filling in with dense shrubs, with abundant snags and downed logs [148]. However, a study in the same region found that American marten were infrequently detected in white spruce forests impacted by spruce beetles, and were twice as likely to be located outside of beetle-damaged areas, despite the abundance of coarse woody debris and snags found in beetle-damaged areas. The author suggested that the low canopy cover in beetle-killed forest did not meet protective needs, and establishing reedgrasses (Calamagrostis spp.) may have reduced habitat for potential small mammal prey [8].
Stands suffering heavy mortality following insect outbreaks may have more complex horizontal and vertical structure than those impacted by logging [50,126] or fire [189]. In central Maine, stands defoliated by eastern spruce budworm were used by American marten, while regenerating clearcuts were not (both were in postdisturbance years 10-20). Stands defoliated by eastern spruce budworm had more snags, downed logs, roots masses, and taller trees compared to regenerating clearcuts. Insect-defoliated stands with <50% canopy closure were intensively used, suggesting that vertical structure provided by large snags can substitute for live trees and that closed-canopy conditions are not required [126]. In north-central Maine, American marten used stands with substantial (<50% canopy closure) eastern spruce budworm mortality significantly more than mature, mixed coniferous-deciduous forest in summer (P=0.003) [35]. In western Newfoundland mature and defoliated conifer stands were used more than expected (P<0.004), while open and early-seral (regenerating) stands had low use [50].
American marten may also be impacted by forest management activities associated with insect outbreaks, including salvage harvest (149, review by [145]), road building, and postharvest site treatment, which may remove large stands of dead canopy trees, create large openings, fragment the landscape, and damage developing understory vegetation and coarse woody debris (review by [145]).Habitat characteristics preferred by American marten have been reviewed by several sources (e.g., [28,38,136,166]). Habitat quality for American marten is largely inferred from behavioral choices of individuals and indices of population density (review by [38]). Much of the information regarding American marten habitat is based on use of particular cover types compared to availability. As a measure of preference, this type of comparison assumes that individuals have equal access to available habitats and that time spent in a habitat translates into a fitness benefit, assumptions which may or may not be true (review by [27]).
American marten habitat preferences may vary by age ([23], reviews by [27,28]), sex ([186], review by [27]), residency [88,123], or season ([62,115], reviews by [27,28,136]). Measurement of habitat preferences may also vary with the scale of activity and method of analysis. Microhabitat selection includes preference for features at sites of specific use, such as resting, denning, or foraging. Stand selection includes preference for structural characteristics of stands, including snag density, tree size, or canopy closure. Home range or landscape selection includes preferences for habitat heterogeneity, interspersion, and juxtaposition. See the following studies for American marten habitat analyses at multiple scales: [62,81,92,106,116,133,134,153,176,180,182].
American marten are associated with many habitat features that are interrelated, including preferences for cover type, seral stage, structural complexity, moisture regime, landscape composition, and prey dynamics. In general, American marten occur mainly in forests and adjacent vegetation types. Late-successional stands of mesic coniferous forest, especially those with complex structure near the ground, are preferred (review by [28]). Forests with >30% canopy cover are considered optimal (review by [38]). Use of deciduous forest types is more common in the eastern part of the American marten distribution, where deciduous components are more typical of mature forests or some prey items are associated with early deciduous seres (review by [136]). Xeric forest types or those lacking complex physical structure are used little if at all. The preference for complex structure near the ground, particularly in winter, seems to be universal (review by [28]).
This section presents information on preferred habitat characteristics, including:In general, American marten inhabit areas with northern, continental climates receiving low mean annual temperatures and substantial winter snow, like the climate of Maine [129], Wyoming [39], or Ontario. Average minimum temperature in Ontario in January is -13 °F (-25 °C); average maximum temperature in July is 77 °F (25 °C). Snow accumulates to 30 to 35 inches (75-90 cm) from early November to about March, melting by mid-May [171]. American marten also inhabit areas with maritime climates that experience heavy rainfall and sporadic snowfall, including Chichagof Island, southeastern Alaska [9], coastal northwestern California [154], and the Queen Charlotte Islands, British Columbia [118]. Transition zones between maritime and continental climate occur at the Kenai National Wildlife Refuge in south-central Alaska [148].
Weather may impact American marten activity, resting site use, and prey availability. One review notes that individuals may become inactive during storms or extreme cold [165]. In Yosemite National Park, American marten were generally inactive during "severe" storms [74]. In interior Alaska, a decrease in above-the-snow activity occurred when ambient temperatures fell below -4 °F (-20 °C) [178]. In southeastern Wyoming, temperature influenced resting site location. Above-snow sites were used during the warmest weather, while subnivean sites were used during the coldest weather [25,182], particularly when temperatures were low and winds were high following storms [182]. High mortality may occur if American marten become wet in cold weather, as when unusual winter rains occur during live trapping (review by [38]). In southeastern Wyoming, temperature was linked to resting site use; above-snow sites were used during the warmest weather, while subnivean sites were used during the coldest weather (P=0.007) [25]. In Yosemite National Park, drought conditions increased the diversity of prey items; American marten consumed fish and small mammal species made more accessible by low snow conditions in a drought year [74].
Importance of snow: Snow is an important habitat feature in many parts of the range of the American marten, providing thermal protection [8,148] and opportunities for foraging and resting [30,37,45,76]. American marten may travel extensively under the snowpack. Subnivean travel routes of >98 feet (30 m) were documented in northeastern Oregon [168], >33 feet (10 m) on the Upper Peninsula of Michigan [168], and up to 66 feet (20 m) in Wyoming [76].
American marten are well adapted to snow. On the Kenai Peninsula, individuals navigated through deep snow regardless of depth, with tracks rarely sinking >2 inches (5 cm) into the snowpack [8]. Researchers on the Kenai Peninsula suggested that snowfall pattern was the most limiting factor to American marten distribution, with American marten presence linked to areas with deep snow [8,148].
Adaptations to deep snow are particularly important in areas where the American marten is sympatric with the fisher, which may compete with and/or prey on American marten. In southeastern Manitoba, one study reported that American marten were less hindered by soft snow cover than fishers [139,141]. In California, American marten were closely associated with areas of deep snow (>9 inches (23 cm)/winter month), while fishers were more associated with shallow snow (<5 inches (13 cm)/winter month). Overlap zones were areas with intermediate snow levels [99]. In Maine, American marten were only common in northern parts of the state, which had frequent, deep snowfalls. They were not common in southern Maine, where snowfall was less and fishers were more abundant. Age and recruitment ratios suggested that there were few reproductive American marten where snow was shallow and few reproductive fishers where snow was deep [98].
Where deep snow accumulates, American marten prefer cover types that prevent snow from packing hard and have structures near the ground that provide access to subnivean sites (review by [27]). While American marten select habitats with deep snow, they may concentrate activity in patches with relatively shallow snow. In north-central Idaho, American marten activity was highest in areas where snow depths were <12 inches (30 cm); the authors suggested that shallow snow allowed for easier burrowing for food and more shrub and log cover [94,96]. In southeastern Ontario, winter snow tracks indicated that activity was concentrated in conifer forests, where snow was shallower relative to other sites and red-backed voles were most abundant [58].
American marten occur in a wide range of elevations throughout their distribution.
Elevation at sites occupied by American marten Location Elevation (feet) Alaska 400 to 1,201 [109] California 8,596 to 11,073 [73]Colorado
7,874 to 14,255 [7] Maine 1,085 to 2,410 [129] Montana 6,400 to 8,200 [44] Oregon 5,495 Washington 2,500 to 6,000 [143] Wyoming 6,444 to 13,730 [39] British Columbia 2,380 to 2,690 [132] Newfoundland 260 to 2,300 [51]American marten prefer habitat with complex physical structure ([35,44,64,81,106,127], reviews by [28,132]), which may be more important than plant community composition (review by [27]). Complex vertical and horizontal structure provides protection from predators, access to subnivean space for winter foraging, and protective thermal microenvironments, particularly in winter (reviews by [13,28]). Horizontal heterogeneity allows individuals to meet their needs in small areas, reducing travel distances (review by [28]). Components of complex physical structure positively associated with American marten habitat use include abundant and/or dense snags [13,21,106,126,127,147,159,176], downfall [44,111,186], logs [13,21,25,106,111,127,147,159,182], stumps [25,127,159,186], coarse woody debris [66,88,123,149], root tip-up mounds [186], shrubs [44,106], and live ground cover [44,111,159].
American marten habitat use has also been linked to relatively high tree basal area [44,62,111,126], tree diameter [13,21,176], tree height [13,126], and canopy closure [13,23,35,37,61,66,68,73,133,159]. Over 5 years of study in northeastern Oregon, 20 American marten showed a strong preference for forests with ≥50% canopy closure; based on availability, stands with 50% to 74% canopy closure were used more than expected while stands with <50% canopy closure were used less than expected (P<0.01) [21]. In Sequoia-Kings Canyon National Park, California, 72% of American marten detections were at sites with ≥40% canopy cover [68]. Some studies suggest that closed canopies are not required, at least not in all seasons. In central Maine, American marten used insect-defoliated stands with <50% canopy closure intensively from May to October. The author suggested that the vertical structure provided by large snags was a suitable substitute for live tree cover [126]. Several studies suggest that American marten avoid habitats lacking canopy closure, particularly in winter, to avoid predation. Few data are available to directly support this hypothesis, and it is also possible that American marten avoid open areas in winter because there is less available prey there (review by [27]).
Other habitat features that provide important cover for American marten include snow (see Importance of snow) and red squirrel middens. In the western part of American marten's range, activity is often associated with red squirrel middens, which provide important structures for natal and maternal denning [18,147] and resting [8,24,139,178], and are associated with traveling [8] and subnivean investigation [149]. In southern Wyoming, predictive models identified the number of red squirrel middens as the most important variable influencing maternal den site selection. Red squirrel middens were also an important variable in natal den site selection [147]. In south-central Alaska, 26 of 37 resting sites were associated with red squirrel middens, with heaviest use of midden resting sites occurring from early November to early April [24]. In Yellowstone National Park, Wyoming, 33% of subnivean access points were associated with red squirrel middens [149].
Characteristics associated with preferred plant communities include cover type, seral stage, moisture regime, use of riparian areas, and landscape characteristics. Use of burned areas has been documented in many studies.
Cover type: Studies from Maine [158,187], Michigan [168], British Columbia [116,132], Manitoba [139,141], Newfoundland [80], Ontario [58,167], Quebec [64], Yukon [155], and reviews [27,28,38,136,165] report a preference for coniferous forests, though it should be noted that deciduous forests are not widely available in many parts of the American marten's distribution. Also, some studies suggesting a preference for coniferous forests compare use of mature coniferous forest to use of regenerating deciduous forest, so it is not clear whether habitat preferences are related to cover type, seral stage, or both (review by ([62]). A variety of forest habitats, including young, deciduous forest, may be used if food and cover are available ([35,132,133], reviews by ([62,136,165]).
In general, American marten avoid cover types that lack overhead cover (e.g., prairies, herbaceous parklands or meadows, clearcuts, and tundra) ([53,73,74,176,187], reviews by [28,155]) due to an absence of preferred prey, structures for denning, concealment cover, escape cover, and/or access points to subnivean spaces (review by ([165]). Though they generally avoid open areas without overstory or shrub cover, American marten may occasionally travel along the edges of open areas or cross narrow open areas (review by [27]).
Use of nonforested habitats varies regionally, with open areas in some regions containing food and structure that open areas in other regions lack (review by [12]). Summer use of nonforested habitats above treeline is common in the montane part of American marten's distribution ([164], review by [28]). The type of nonforested habitat is important; open areas such as clearcuts, tornado blowdowns, or burned areas with large amounts of coarse woody debris may lack shrub or overstory cover but still provide adequate cover from tall herbs and debris, while protective cover in open grasslands, alpine zones, or other areas with short herbaceous vegetation may be lacking (review by [27]). Use of nonforested habitats may also be related to the proximity of and interspersion with closed-canopy cover types [159,176]. See General cover requirements for more information on this topic.
Seral stage: In general, American marten prefer late successional forests (e.g., see studies from California [92,93,153], Idaho [94,96,110,176,180], Maine [126,127,162,187], Oregon [21], Wyoming [30], Alberta [138], British Columbia [106,132], Newfoundland [50,66,157], Quebec [64], and Yukon [155]). The structural features important to American marten that develop with successional advancement include overhead cover, high volumes of large-diameter coarse woody debris, and small-scale horizontal heterogeneity of vegetation (review by [28]). American marten may use early-seral stands, particularly if complex physical structure is available ([6,35,62,88,116,123,132,186], review by [174]), stands contain attractions like seasonally abundant food items [110,162], or if mature stands are lacking across the landscape [6].
Moisture regime: Several studies indicate a preference for mesic over xeric sites, including studies in Colorado [7], Idaho [94,96], Montana [23,43,53], Oregon [21], Washington [117], British Columbia [106,116], and the Northwest Territories [115]. At temperate latitudes, mesic forests used by American marten are commonly riparian (review by [27]).
Riparian areas: Riparian areas contain habitat features important for American marten in many parts of their range [25,53,68,152,159,176,178]. They may provide large amounts of coarse woody debris [25,178] and/or high prey density [25], leading to enhanced foraging opportunities [152,176,178]. Riparian areas may also offer cool temperatures and access to water in summer [176]. In logged landscapes, riparian areas are often left uncut, providing structurally complex or mature forest [25,176].
In northeastern California, stream corridors were important for American marten movement and foraging [152]. In northern Idaho, individuals within a home range were located closer to streams than to random locations (P<0.01), and resting sites and travel routes were often located near riparian corridors [176]. In southeastern Wyoming, winter resting sites were closer to streams and lakes than expected (P=0.007) [25]. Below 6,725 feet (2,050 m) elevation in the northern Sierra Nevada, American marten strongly preferred riparian lodgepole pine plant associations (P<0.05). Riparian areas were used more for activity than resting, while adjacent mixed-conifer forests were used more for resting than activity. Riparian lodgepole pine forests with lush herbaceous cover were primary foraging areas [159]. In Grand Teton National Park, one natal den was located in a cottonwood (Populus spp.) along the Snake River [37].
Riparian areas were key components of American marten home ranges in areas burned 8 years previously in interior Alaska. The home ranges of 10 American marten were centered in habitat around the Pitka Fork and Salmon rivers. Home range boundaries coincided with transition areas between riparian and nonriparian habitats. American marten clearly associated with riparian areas in daily activities. The author attributed this association to the large amounts of dead and down wood and vertical layering of log debris in riparian areas, and suggested that these habitat features offered both foraging opportunities and sufficient protective cover [178]. See Wildfire Case Study 1 for more information on this study.
Some studies suggest that riparian areas may constitute a barrier to movement or may shape home range boundaries. On the Kenai Peninsula, Alaska, individuals avoided ice-covered water (P<0.001) [8]. Very few tracks (3 of 251) were found on frozen lakes and rivers >50 feet (15 m) wide in southeastern Manitoba [139,141]. In south-central Alaska, home range boundaries included creeks and a major river [29]. However, some individuals do cross large rivers. Individuals in interior Alaska regularly swam across a river 154 feet (50 m) wide, sometimes more than once a day [109]. In southwestern Montana, at least one individual swam the Madison River [43]. In Yosemite National Park, California, individuals regularly crossed streams and traveled up to 330 feet (100 m) on frozen creek beds [74]. In interior Alaska, although home range boundaries were coincident with riparian areas, rivers presented no barrier to movement. Animals crossed rivers freely even in summer, sometimes more than once in 24 hours: "One marten was observed swimming the Pitka Fork, even diving under water for a short distance before emerging on the bank" [178].
Landscape characteristics: Plant community landscape metrics, including the juxtaposition and configuration of patches, may be important in American marten habitat selection [159,180]. However, one review suggests that the impacts of landscape features like fragmentation likely vary by geographic location [12], making broad inferences difficult.
Several studies suggest that landscape fragmentation has negative consequences for American marten ([75,80,81,116,180], review by [27]). Landscape metrics associated with fragmentation include patch size, edge indices, and habitat interspersion. Though highly fragmented forests may contain suitable patches of habitat for American marten, preferred habitats may be so separated by open areas that they are essentially unavailable (review by [27]) and/or predation risk is increased [180]. A few studies suggest that American marten favor large patches [34,92,168]. In an industrial forest in north-central Maine, forest patches used by American marten were 18 times larger than unused patches (median 67 acres (27 ha) vs. 3.7 acres (1.5 ha)) (P<0.003). Patches used by residents were closer to the nearest patch >6.7 acres (2.7 ha) (P=0.057) and to an adjacent forest preserve (P=0.075) than patches with no observed use [34]. On the Upper Peninsula of Michigan, American marten selected for large patches (P=0.05); 194 out of 232 locations were in conifer patches >345 acres (140 ha) [168].
American marten show no clear association with edge habitat, probably because of the variety of habitats studied and the inability of telemetry studies to detect fine-scale habitat preferences (review by [27]). Some studies suggest that interior forest areas are preferred [92]. American marten habitat use is negatively related to the proportion of the landscape in high-contrast edge habitat, like that between adjacent logged and unlogged forest [62,180]. However, edge indices were unrelated to American marten habitat use in an industrial forest in north-central Maine [34]. American marten in an experimental forest in southern British Columbia tended to use edges between forest and small forest openings (0.2-25 acres (0.1-10 ha)), avoiding forest farther from openings [86]. Several studies have documented American marten foraging in edge habitat between forested and open areas [29,76,77,86,152,159,181] (see Foraging).
Habitat interspersion was an important habitat feature of American marten habitat in the northern Sierra Nevada. American marten selected for tall, dense forest stands that were near meadows and that had many large snags, stumps, and logs (P<0.001). When active, individuals preferred to be within 200 feet (60 m) of a meadow and rarely used sites more than 1,300 feet (400 m) from meadows [159]. Some sources suggest that the mosaic of seral stages and cover types created by disturbances such as fire [88,94,96,109,123] and insect outbreaks [148] are important components of American marten habitat.
The scientific name of the American marten is Martes americana (Turton) (Mustelidae) [38,184].
As many as 14 American marten subspecies have been recognized in the past. Some authorities suggest that subspecies partitioning
was completely arbitrary, noting that many of the differences between subspecies were relicts of small sample size, variable coat
color, or inadequate sampling. Two subspecies groups have been tentatively recognized based on cranial characters, fossil history [38], and mitochondrial DNA analyses [31]. The groups intergrade morphologically and genetically, indicating hybridization [136].
Martes americana americana subspecies group, including:
Martes americana abieticola Preble
Martes americana abietinoides Gray
Martes americana actuosa (Osgood)
Martes americana americana (Turton)
Martes americana atrata (Bangs)
Martes americana brumalis Bangs
Martes americana kenaiensis (Elliot) [136]
Martes americana caurina subspecies group, including:
Martes americana caurina (Merriam)
Martes americana humboldtensis Grinnell and Dixon
Martes americana nesophila (Osgood)
Martes americana origenes Rhoads
Martes americana vancouverensis Grinnell and Dixon
Martes americana vulpina (Rafinesque)
Martes americana sierrae Grinnell and Storer [136]
Amerika samuru (Martes americana) Dələkimilər fəsiləsinə və Dələlər yarımfəsiləsinə və Dələ cinsinə aid heyvan növü.
Mart Amerika (martes americana) a zo ur bronneg kigdebrer bihan eus kerentiad ar mustelideged. Hervez klaskourien 'zo e furmfe poblañs kornôg Stadoù-Unanet Amerika ur spesad distag, Martes caurina hec'h anv.
Bevañ a ra er c'hoadegoù pin e Kanada hag Alaska hag en un darn eus ar Menezioù Roc'hellek. War zigresk eo aet e boblañs abalamour d'an hemolc'h ha da zistruj e diriad met fonnus eo c'hoazh.
Hir ha moan eo korf mart Amerika ha goloet gant ur vlevenn c'hell. Sklaeroc'h eo e c'houzoug eget ar peurrest eus e gorf. E lost zo hir ha blevek. Begek eo e vin ha damguzh eo e skilfoù, evel re ar c'hizhier, ar pezh a lak anezhañ da bignat aes er gwez. Bez' ez eus torchennigoù dindan e bavioù hag a harp anezhañ da gerzhout war an erc'h.
Un hollzebrer eo. Chaseal a ra anevaled bihan evel gwiñver rous Norzhamerika (Tamiasciurus hudsonicus) met gallout a ra ivez debriñ raned, amprevaned, pesked pe frouezh. Oberiantoc'h eo diouzh an noz, an abardaez hag abred diouzh ar mintin. N'eo ket un aneval a vev a-stroll hag en e-unan e chom en diavaez eus koulz ar parañ a c'hoarvez e-pad an hañv. Ampellaet e vez stagadenn ar vi er mammog ha ganet e vez ar c'helin (etre 1 ha 5) en nevez-amzer war-lerc'h.
Ar pared a zifenn start un dachennad 8 km² well-wazh.
Doñvaet e c'hell bezañ ha mont da loen-ti.
Hemolc'het eo evit e greoñ, heñvel a-walc'h ouzh hini ar sebelinez, met nebeutoc'h eget gwechall. E boblañs a oa digresket kalz e deroù an XXvet kantved met ur politikerezh gwarez en deus roet tro dezhi da greskiñ adarre.
La marta nord-americana o el mart americà (Martes americana) és una espècie de mamífer pertanyent a la família dels mustèlids.[1]
Es troba a Nord-amèrica: el Canadà i els Estats Units.[2]
La marta nord-americana o el mart americà (Martes americana) és una espècie de mamífer pertanyent a la família dels mustèlids.
Der Fichtenmarder (Martes americana) ist eine in Nordamerika verbreitete Raubtierart aus der Gattung der Echten Marder. Er sieht dem europäischen Baummarder sehr ähnlich und wird manchmal als dessen Unterart angesehen.
Wie bei den meisten Mardern ist der Körper des Fichtenmarders langgestreckt und schlank, die Gliedmaßen sind kurz. Das Fell ist überwiegend braun gefärbt, der Kopf ist grau, die Beine und der Schwanz dunkelbraun oder schwarz. Wie der Baummarder hat er einen gelben Kehlfleck, ist aber deutlich kleiner und zierlicher als dieser. Männchen erreichen eine Kopfrumpflänge von 36 bis 45 Zentimeter, der buschige Schwanz wird 20 bis 23 Zentimeter lang und das Gewicht beträgt 0,47 bis 1,25 Kilogramm. Sie sind im Durchschnitt 65 % schwerer als die Weibchen, die ein Gewicht von 0,28 bis 0,85 Kilogramm erreichen, eine Kopfrumpflänge von 32 bis 40 Zentimeter und eine Schwanzlänge von 18 bis 20 Zentimeter haben.[1]
Zahnformel: I 3/3, C 1/1, P 4/4, M 1/2 = 38.[1]
Fichtenmarder sind in Nordamerika beheimatet, ihr Verbreitungsgebiet umfasst große Teile Alaskas und Kanadas mit Ausnahme des äußersten Norden. In den USA sind sie im Gebiet der Rocky Mountains, in der Region der Großen Seen und in Neuengland verbreitet. Ihr Lebensraum sind vorwiegend Nadelwälder.
Fichtenmarder sind in erster Linie nachtaktiv. Tagsüber ziehen sie sich in hohle Baumstämme, Felsspalten oder verlassene Baue anderer Tiere zurück, um in der Nacht auf Nahrungssuche zu gehen. Dabei halten sie sich sowohl auf den Bäumen als auch am Boden auf, außerdem können sie sehr gut schwimmen und tauchen. Sie halten keine Winterruhe.
Wie die meisten Marder sind sie territorial. Die durchschnittliche Reviergröße beträgt 8,1 Quadratkilometer bei Männchen und 2,3 Quadratkilometer bei Weibchen, kann aber je nach Habitat und Nahrungsangebot deutlich variieren. Vom Menschen ausgesetzte Exemplare bleiben ebenfalls meist einige Jahre in der Nähe des Ortes ihrer Freisetzung. Einzelne Tiere wandern jedoch auch, ein männlicher Marder legte beispielsweise nach der Freilassung im März und dem folgenden November 80 Kilometer zurück. Aus Alaska wird berichtet, dass die Marder dazu tendieren, im Frühjahr höhere Lagen aufzusuchen und im Herbst wieder herabkommen.[2] Sie leben vorwiegend einzelgängerisch, manchmal kann man aber ein Männchen und Weibchen miteinander beobachten.
Fichtenmarder sind Allesfresser, wobei allerdings Kleinsäuger wie Nagetiere den Hauptbestandteil der Nahrung ausmachen. Daneben nehmen sie auch Vögel, Insekten, Aas und auch Früchte zu sich.[2]
Die Paarung erfolgt im Hochsommer zwischen Juni und August, aufgrund einer Keimruhe nistet sich die befruchtete Eizelle aber erst im Februar ein. Die eigentliche Tragzeit dauert rund einen Monat, und im März oder April bringt das Weibchen ein bis fünf (durchschnittlich 2,6) Jungtiere zur Welt. Diese öffnen mit 40 Tagen die Augen, werden mit sechs Wochen entwöhnt und sind mit 3,5 Monaten ausgewachsen. Die Geschlechtsreife tritt im zweiten Lebensjahr ein. Die Lebenserwartung beträgt in freier Natur bis zu zwölf Jahre, in Menschenobhut bis zu 17.
Der Fichtenmarder wurde im Jahr 1806 durch den englischen Naturforscher William Turton erstmals wissenschaftlich beschrieben. Es wurden zahlreiche Unterarten beschrieben von denen im Handbook of the Mammals of the World acht anerkannt werden.[1] Äußerlich lassen sich die Unterarten kaum unterscheiden. Allerdings wurde mit Hilfe von DNA-Vergleichen festgestellt, dass der Fichtenmarder aus zwei Kladen besteht, von denen eine deckungsgleich mit der an der Pazifikküste vorkommenden Unterart Martes americana caurina ist. Da letztere an der Kontaktzone nur wenig mit den übrigen Fichtenmardern hybridisiert, wurde sie als eigenständige Art anerkannt.[3][4]
Weil er wegen des für wertvoll erachteten Fichtenmarderfells von Fallenstellern gejagt wurde, ist der Fichtenmarder in weiten Teilen seines Verbreitungsgebiets selten geworden. In Neuengland und in Michigan war er zeitweise ganz ausgerottet, wurde inzwischen aber erfolgreich wieder eingebürgert. Regional ist er heute geschützt, gilt aber wegen seiner Häufigkeit vor allem im wenig besiedelten Norden Kanadas global nicht als bedroht.
Fichtenmarder im
und im Grand-Teton-Nationalpark
Der Fichtenmarder (Martes americana) ist eine in Nordamerika verbreitete Raubtierart aus der Gattung der Echten Marder. Er sieht dem europäischen Baummarder sehr ähnlich und wird manchmal als dessen Unterart angesehen.
De Amerikaanske marter (Latynske namme: Martes americana) is in sûchdier út it skift fan 'e rôfdieren (Carnivora), de famylje fan 'e martereftigen (Mustelidae), it skaai fan 'e marters (Martes) en it lyknammige ûnderskaai fan 'e marters (Martes), dêr't ek de beamotter (Martes martes) en de stienmurd (Martes foina) ta hearre, dy't yn Fryslân foarkomme. De Amerikaanske marter is lânseigen yn it grutste diel fan Kanada en Alaska en yn beheinde dielen fan 'e legere achtenfjirtich Feriene Steaten. Dit bist dielt syn ferspriedingsgebiet mei in oare martersoarte, de fiskmarter (Martes pennanti), mar is dêrfan te ûnderskieden trochdat er lytser en ljochter fan kleur is.
De Amerikaanske marter is lânseigen yn it grutste part fan Kanada (ynkl. Vancouvereilân en de Keninginne Sjarlotte-eilannen), mar komt net foar yn Nûnavût, Nûnavik, it noarden fan 'e Noardwestlike Territoaria en Labrador en op 'e prêrjes fan súdlik Alberta, súdlik Saskatchewan en súdwestlik Manitoba. Yn it súdeasten ûntbrekt er yn 'e súdlike punt fan Ontario, op Prins Edwardeilân en op it skiereilân fan Nij-Skotlân. Op it eilân Nijfûnlân is syn fersprieding fersnipele.
Bûten Kanada komt de Amerikaanske marter foar yn hast hiel Alaska, útsein de noard- en westkust, de Aleoeten, it Alaska-skiereilân en de eilannen fan Súdeast-Alaska. Yn 'e legere achtenfjirtich Feriene Steaten is it ferspriedingsgebiet fan dit bist beheind ta noardlik Maine, Opper-Michigan, noardlik Wiskonsin, noardlik Minnesota, de noardlike en sintrale Rocky Mountains, de Cascades en de Sierra Nevada.
De Amerikaanske marter hat trochinoar in kop-romplingte fan 32-45 sm, mei in sturtlingte fan 13-23 sm en in gewicht fan 0,5-1,4 kg. Syn liif is lang en rank, mei koarte lidden en in plomsturt. De earen binne grut en rûn op in rûchwei trijehoekige kop mei in skerpe foarútstykjende snút. De lange, sidesêfte pels kin bleek gielich, kastanjebrún of hast swart wêze en alle nuânses dêrtuskenyn. Op 'e kop is it hier yn 'e regel ljochter as op it lichem, wylst it op 'e poaten en de sturt ornaris wat dûnkerder is. Amerikaanske marters hawwe in tige karakteristike bef op 'e kiel en it boarst dy't bleekgiel oant feloranje fan kleur is. Der bestiet by dit bist in oansjenlike seksuële dimorfy, mei't mantsjes oant 15% grutter en oant 65% swierder wêze kinne as wyfkes. Fan oansjen is der lykwols gjin ferskil tusken mantsjes en wyfkes. De Amerikaanske marter dielt syn ferspriedingsgebiet mei in oare martersoarte, de fiskmarter (Martes pennanti), mar is dêrfan te ûnderskieden trochdat er lytser en ljochter fan kleur is.
Amerikaanske marters libje oer it algemien yn wâldbiotopen. Dêrby jouwe se de foarkar oan folwoeksen nullewâlden en mingde wâlden. Yn 'e Rocky Mountains, de Cascades en de Sierra Nevada komme se foar oant de beamgrins, mar net dêrboppe.
De Amerikaanske marter is in territoriaal bist, mar de grutte fan syn territoarium rint sterk útinoar en hinget ôf fan geslacht, terreinsgesteldheid, de tichtens fan 'e begroeiïng, de oanwêzigens fan proaidieren en ferskate oare faktoaren. Lichemsgrutte hat lykwols gjin ynfloed op 'e grutte fan it territoarium. By in wittenskiplik ûndersyk út 1987 waard fêststeld dat mantsjes yn Maine in territoarium hiene fan trochinoar 0,1 km² (oftewol 10 ha) en yn Minnesota fan 15,7 km², wylst wyfkes yn Maine in territoarium ûnderholden fan yn trochsneed 0,1 km² en yn Wiskonsin fan 7,7 km². Amerikaanske marters sette har territoarium ôf troch geurflaggen te pleatsen, dy't oanbrocht wurde mei de anaalklieren sawol as troch te urinearjen. Territoaria fan folwoeksen mantsjes oerlaapje inoar net, mar tusken it territoarium fan in folwoeksen mantsje en dat fan in healwoeksen mantsje, tusken dat fan in mantsje en dat fan in wyfke en tusken dat fan wyfkes ûnderling kin oerlaping foarkomme.
Amerikaanske marters kinne simmerdeis wol 60% fan 'e tiid yn 't spier wêze, wylst se by 't winter faak mar 16% fan 'e tiid wat útfine. Se hawwe mar beheinde ûnderhûdske fetfoarrieden, en binne dêrom kwetsber foar waarmteferlies. Dat is dan ek de reden dat se winterdeis faak in grut diel fan 'e dei yn in ûnechte wintersliep trochbringe, wêrby't de lichemstemperatuer ferlege wurdt, wat in protte enerzjy útsparret. Ek in tsjûk sniedek, dat as isolaasjemateriaal foar syn hoale fungearret, helpt de Amerikaanske marter om waarmteferlies te beheinen. Amerikaanske marters binne gjin wiere dei- of nachtdieren, en se kinne sadwaande sawol deis as nachts aktyf wêze, ôfhinklik fan 'e beskikberheid fan proaien en de temperatuer. De ôfstân dy't se yn ien etmiel ôflizze is trochinoar 900 m, mar kin yn ekstreme gefallen oprinne oant 14 km. Djippe snie hawwe Amerikaanske marters gjin swierrichheden mei; se binne lichtfuottich genôch om net mear as 5 sm yn wei te sakjen.
Folwoeksen Amerikaanske marters libje ornaris in solitêr bestean, behalven yn 'e peartiid, dy't yn july of augustus falt en foar wyfkes sa'n twa wiken duorret. Beide geslachten binne dêrby polygaam en de wyfkes kinne ferskate perioaden fan tyldrift trochmeitsje. Trochdat de Amerikaanske marter in ferlingde draachtiid ken, wurdt de ymplantaasje fan it embryo opkeard oant de ein fan 'e winter, wêrnei't de wiere draachtiid likernôch in moanne duorret. Yn dy tiid makket it wyfke in hoale om yn te befallen, faak yn holle beammen, ûnder beamwoartels, beamstobben of rotsen. Ein maart of yn april smyt it wyfke dan in nêst fan 1-5 jongen, dy't mei 42 dagen ôfwûn wurde. Mei 50 dagen komme de jongen foar it earst út 'e hoale foar 't ljocht. Se bliuwe by de mem oant de ein fan harren earste simmer en sette dan hjerstmis op eigen manneboet ôf. Amerikaanske marters binne nei in jier geslachtsryp, hoewol't se yn 'e praktyk faak pas oan 'e fuortplanting dielnimme as se twa jier âld binne.
De libbensferwachting fan in Amerikaanske marter yn it wyld is op syn heechst 14½ jier (sa't yn ien dokumintearre gefal fêststeld waard), al helje se dat yn 'e measte gefallen net. Yn finzenskip waard it âldste eksimplaar 15 jier. Amerikaanske marters binne kwetsber foar predaasje troch rôffûgels, lykas de keningsearn (Aquila chrysaetos), de see-earn (Haliaeetus leucocephalus) en de Amerikaanske oehoe (Bubo virginianus), wat nei alle gedachten de reden is dat se iepen plakken mije en safolle mooglik ûnder de beskutting fan beammen bliuwe. Oare natuerlike fijannen fan 'e Amerikaanske marter binne de reade lynks (Lynx rufus), de Kanadeeske lynks (Lynx canadensis), de poema (Puma concolor), de Amerikaanske swarte bear (Ursus americanus), de grizzlybear (Ursus arctos horribilis), de grize wolf (Canis lupus), de prêrjewolf (Canis latrans), de foks (Vulpes vulpes) en de fiskmarter (Martes pennanti).
Amerikaanske marters binne opportunistyske rôfdieren, dy't ferlet hawwe fan sa'n 80 kaloryen deis. Harren dieet bestiet foar in grut part út wrotmûzen, hoewol't se ek wol gruttere proaien pakke, oant de Amerikaanske hazze (Lepus americanus) oan ta. De gongberste proaisoarten binne foar de Amerikaanske marter lykwols reade wrotmûzen (Myodes) en fjildmûzen (Microtus). De hartmûs (Peromyscus maniculatus) wurdt lykwols wer folle minder iten as dat men op basis fan 'e grutte fersprieding ferwachtsje soe. Op 'e Keninginne Sjarlotte-eilannen, foar de kust fan Britsk-Kolumbia, makken fûgels fierhinne it menu fan 'e Amerikaanske marter út, en yn oare kustgebieten nimme wierskynlik ek fisken in wichtich plak yn. Yn 'e simmer is it dieet fan 'e Amerikaanske marter folle ferskater as by 't winter. Sa frette se simmerdeis ek fruchten en oare fegetaasje en ynsekten.
De Amerikaanske marter hat de IUCN-status fan "net bedrige", mei't er yn syn ferspriedingsgebiet noch rûnom foarkomt en om't de populaasje stabyl liket te wêzen. Hoewol't de populaasje troch bejaging (foar de tichte en sidesêft oanfielende pels) en it kapjen fan bosken ôfnommen is, komt de Amerikaanske marter noch altyd folle mear foar as de fiskmarter. de Nijfûnlânske beamotter, de Nijfûnlânske ûndersoarte fan 'e Amerikaanske marter, wurdt lykwols beskôge as bedrige.
Der binne trettjin erkende ûndersoarten fan 'e Amerikaanske marter:
De Amerikaanske marter (Latynske namme: Martes americana) is in sûchdier út it skift fan 'e rôfdieren (Carnivora), de famylje fan 'e martereftigen (Mustelidae), it skaai fan 'e marters (Martes) en it lyknammige ûnderskaai fan 'e marters (Martes), dêr't ek de beamotter (Martes martes) en de stienmurd (Martes foina) ta hearre, dy't yn Fryslân foarkomme. De Amerikaanske marter is lânseigen yn it grutste diel fan Kanada en Alaska en yn beheinde dielen fan 'e legere achtenfjirtich Feriene Steaten. Dit bist dielt syn ferspriedingsgebiet mei in oare martersoarte, de fiskmarter (Martes pennanti), mar is dêrfan te ûnderskieden trochdat er lytser en ljochter fan kleur is.
A fuina americana (Martes americana (Turton, 1806)) ye un mamifero carnivoro d'a familia d'os mustelidos, propia d'a fauna d'America d'o Norte (Canadá y Estatos Unitos).
Puet distinguir-se d'a Martes pennanti por o suyo tamanyo (Martes americana ye mas chicota) y amás en tener una color marrona mas clara. A especie tien dimorfismo sexual: os masclos miden entre 560 y 680 mm y as femellas son una mica mas chicotas; antiparte, os masclos pesan alto u baixo 1,3 kg y as femellas nomás que 850 gr.
Martes americana ye una especie omnivora, encara que o suyo alimento habitual ye a carne, fendo cazata de chicotz mamifers (mas que mas d'a especie Tamiasciurus hudsonicus, un esquiruelo). Gosan estar animals de vida solitaria, que nomás se troban en epoca de reproducción.
A fuina americana (Martes americana (Turton, 1806)) ye un mamifero carnivoro d'a familia d'os mustelidos, propia d'a fauna d'America d'o Norte (Canadá y Estatos Unitos).
Puet distinguir-se d'a Martes pennanti por o suyo tamanyo (Martes americana ye mas chicota) y amás en tener una color marrona mas clara. A especie tien dimorfismo sexual: os masclos miden entre 560 y 680 mm y as femellas son una mica mas chicotas; antiparte, os masclos pesan alto u baixo 1,3 kg y as femellas nomás que 850 gr.
Martes americana ye una especie omnivora, encara que o suyo alimento habitual ye a carne, fendo cazata de chicotz mamifers (mas que mas d'a especie Tamiasciurus hudsonicus, un esquiruelo). Gosan estar animals de vida solitaria, que nomás se troban en epoca de reproducción.
Американ луй (лат. Martes americana ) – Йӱдвел Америкын йос-влак (Mustelidae) йамагатын гыч изи янлык. Капше 32 - 45 см, почше 14 - 23 см, нелытше 0,5 - 1,3 (узо) , 0,3 - 0,9 (ава) кг.
The American marten[1] (Martes americana), also known as the American pine marten, is a species of North American mammal, a member of the family Mustelidae. The species is sometimes referred to as simply the pine marten. The name "pine marten" is derived from the common name of the distinct Eurasian species, Martes martes. It is found throughout Canada, Alaska, and parts of the northern United States. It is a long, slender-bodied weasel, with fur ranging from yellowish to brown to near black. It may be confused with the fisher (Pekania pennanti), but the marten is lighter in color and smaller. Identification of the marten is further eased by a characteristic bib that is a distinctly different color than the body. Sexual dimorphism is pronounced, with males being much larger.
The diet is omnivorous and varies by season, but relies chiefly on small mammals like voles. They are solitary except during the mid-summer breeding season. Embryonic implantation is delayed until late winter, however, with a litter of 1–5 kits born the following spring. Young stay with the mother in a constructed den until the fall and reach sexual maturity by one year old.
Their sable-like fur made them a thoroughly trapped species during the height of the North American fur trade. Trapping peaked in 1820, and populations were depleted until after the turn of the century. Populations have rebounded since, with them being considered a species of least-concern by the IUCN; however, they remain extirpated from some areas of the Northeast, and of the 7 subspecies, one is threatened.
The Pacific marten (Martes caurina) was formerly thought to be conspecific, but genetic studies support both being distinct species from one another.[6][7][8][9] The Pacific marten has a longer snout and a broader cranium than the American marten.
Seven subspecies have been recognized.[10] None of the subspecies are separable based on morphology and subspecies taxonomy is usually ignored except for conservation issues centered around subspecies rather than ranges.[11]
A fossil species from the Late Pleistocene to Early Holocene known as Martes nobilis is considered synonymous with the American marten.[5]
The American marten is broadly distributed in northern North America. From north to south its range extends from the northern limit of the treeline in arctic Alaska and Canada south to New York. From east to west, its distribution extends from Newfoundland to western Alaska, and southwest to the Pacific coast of Canada. The American marten's distribution is vast and continuous in Canada and Alaska. In the northeastern and midwestern United States, American marten distribution is limited to mountain ranges that provide preferred habitats. Over time, the distribution of American marten has contracted and expanded regionally, with local extirpations and successful recolonizations occurring in the Great Lakes region and some parts of the Northeast.[12] The American marten has been reintroduced in several areas where extinction occurred, although in some cases it has instead been introduced into the range of the Pacific marten.[13] It is considered extirpated from Pennsylvania, Maryland, Massachusetts, West Virginia, Ohio, New Jersey, and Illinois.[14]
Martens were once thought to live only in old conifer (evergreen) forests but further study shows that martens live in both old and young deciduous (leafy) and conifer forests[15] as well as mixed forests, including in Alaska and Canada, and south into northern New England,[16][17][18] and the Adirondacks in New York.[19] Groups of martens also live in the Midwest, in Wisconsin and much of Minnesota.[15] Trapping and destruction of forest habitat have reduced its numbers, but it is still much more abundant than the larger fisher. The Newfoundland subspecies (M. a. atrata) is considered to be threatened.
A broad, natural hybrid zone between the Pacific and American martens is known to exist in the Columbia Mountains, as well as Kupreanof and Kuiu Islands in Alaska.[20] Several translocations of American marten have been made without regard to the Pacific marten, threatening the latter species. On Dall Island, American martens have been introduced and are hybridizing with the native Pacific marten population, which may put them at risk. On many islands throughout the Alexander Archipelago, American martens have been introduced and are present, with no sign of the Pacific martens; it is unknown whether the islands previously had no marten species until American martens were introduced, or whether the Pacific martens existed on those islands previously but were extirpated by the introduced American martens. In addition, genetic evidence of introgression with American martens is present in other parts of the Pacific marten's range, which is likely also a consequence of American marten introductions.[8][21][20]
Compared to other carnivores, the American marten population density is low for their body size. One review reports population densities ranging from 0.4 to 2.5 individuals/km2.[12] Population density may vary annually[22] or seasonally.[23] Low population densities have been associated with a low abundance of prey species.[12]
Home range size of the American marten is extremely variable, with differences attributable to sex,[24][25][26][27] year, geographic area,[12] prey availability,[12][28] cover type, quality or availability,[12][28] habitat fragmentation,[29] reproductive status, resident status, predation,[30] and population density.[28] Home range size does not appear to be related to body size for either sex.[24] Home range size ranged from 0.04 sq mi (0.1 km2) in Maine to 6.1 sq mi (15.7 km2) in Minnesota for males, and 0.04 sq mi (0.1 km2) in Maine to 3.0 sq mi (7.7 km2) in Wisconsin for females.[28]
Males generally exhibit larger home ranges than females,[24][25][26][27] which some authors suggest is due to more specific habitat requirements of females (e.g., denning or prey requirements) that limit their ability to shift home range.[25] However, unusually large home ranges were observed for 4 females in two studies (Alaska[31] and Quebec[22]).
Home ranges are indicated by scent-marking. American marten male pelts often show signs of scarring on the head and shoulders, suggesting intrasexual aggression that may be related to home range maintenance.[28] Home range overlap is generally minimal or nonexistent between adult males[23][26][32] but may occur between males and females,[23][26] adult males and juveniles,[26][33] and between females.[34]
Several authors have reported that home range boundaries appear to coincide with topographical or geographical features. In south-central Alaska, home range boundaries included creeks and a major river.[26] In an area burned 8 years previously in interior Alaska, home range boundaries coincided with transition areas between riparian and nonriparian habitats.[34]
The American marten is a long, slender-bodied weasel about the size of a mink with relatively large, rounded ears, short limbs, and a bushy tail. American marten have a roughly triangular head and sharp nose. Their long, silky fur ranges in color from pale yellowish buff to tawny brown to almost black. Their head is usually lighter than the rest of their body, while their tail and legs are darker. American marten usually have a characteristic throat and chest bib ranging in color from pale straw to vivid orange.[13] Sexual dimorphism is pronounced, with males averaging about 15% larger than females in length and as much as 65% larger in body weight.[13]
Total length ranges from 1.5 to 2.2 feet (0.5–0.7 m),[35][12] with tail length of 5.4 to 6.4 inches (135–160 mm),[35] Adult weight ranges from 1.1 to 3.1 pounds (0.5–1.4 kg)[35][12] and varies by age and location. Other than size, sexes are similar in appearance.[12] American marten have limited body-fat reserves, experience high mass-specific heat loss, and have limited fasting endurance. In winter, individuals may go into shallow torpor daily to reduce heat loss.[36]
American marten activity patterns vary by region,[28] though in general, activity is greater in summer than in winter.[13][36] American marten may be active as much as 60% of the day in summer but as little as 16% of the day in winter[36] In north-central Ontario individuals were active about 10 to 16 hours a day in all seasons except late winter when activity was reduced to about 5 hours a day. In south-central Alaska, American marten were more active in autumn (66% active) than in late winter and early spring (43% active).[26]
American marten may be nocturnal or diurnal. Variability in daily activity patterns has been linked to activity of major prey species,[28][37] foraging efficiency,[26] sex, reducing exposure to extreme temperatures,[26][28][34] season,[32][36][37] and timber harvest. In south-central Alaska, American marten were nocturnal in autumn, with strong individual variability in diel activity in late winter. Activity occurred throughout the day in late winter and early spring.[26]
Daily distance traveled may vary by age,[31] sex, habitat quality, season,[32] prey availability, traveling conditions, weather, and physiological condition of the individual. One marten in south-central Alaska repeatedly traveled 7 to 9 miles (11–14 km) overnight to move between 2 areas of home range focal activity.[26] One individual in central Idaho moved as much as 9 miles (14 km) a day in winter, but movements were largely confined to a 1,280-acre (518 ha) area. Juvenile American marten in east-central Alaska traveled significantly farther each day than adults (1.4 miles (2.2 km) vs. 0.9-mile (1.4 km)).[31]
The weather may impact American marten activity, resting site use, and prey availability. Individuals may become inactive during storms or extreme cold.[28][38] In interior Alaska, a decrease in above-the-snow activity occurred when ambient temperatures fell below −4F (−20C).[34]
A snowy habitat in many parts of the range of the American marten provides thermal protection[33] and opportunities for foraging and resting.[32] American marten may travel extensively under the snowpack. Subnivean travel routes of>33 feet (10 m) on the Upper Peninsula of Michigan.[39]
American marten are well adapted to snow. On the Kenai Peninsula, individuals navigated through deep snow regardless of depth, with tracks rarely sinking>2 inches (5 cm) into the snowpack. Snowfall patterns may affect distribution, with the presence of American marten linked to deep snow areas.[33]
Where deep snow accumulates, American marten prefer cover types that prevent snow from packing hard and have structures near the ground that provide access to subnivean sites.[40] While American marten select habitats with deep snow, they may concentrate activity in patches with relatively shallow snow.
American marten reach sexual maturity by 1 year of age, but effective breeding may not occur before 2 years of age.[36] In captivity, 15-year-old females bred successfully.[13][41] In the wild, 12-year-old females were reproductive.[41]
Adult American marten are generally solitary except during the breeding season.[13] They are polygamous, and females may have multiple periods of heat.[41] Females enter estrus in July or August,[36] with courtship lasting about 15 days.[13] Embryonic implantation is delayed until late winter, with active gestation lasting approximately two months.[15] Females give birth in late March or April to a litter ranging from 1 to 5 kits.[36] Annual reproductive output is low according to predictions based on body size. Fecundity varies by age and year and may be related to food abundance.[12]
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Females use dens to give birth and to shelter kits. Dens are classified as either natal dens, where parturition takes place, or maternal dens, where females move their kits after birth.[12] American marten females use a variety of structures for natal and maternal denning, including the branches, cavities or broken tops of live trees, snags,[32] stumps, logs,[32] woody debris piles, rock piles, and red squirrel (Tamiasciurus hudsonicus) nests or middens. Females prepare a natal den by lining a cavity with grass, moss, and leaves.[28] They frequently move kits to new maternal dens once kits are 7–13 weeks old. Most females spend more than 50% of their time attending dens in both pre-weaning and weaning periods, with less time spent at dens as kits aged. Paternal care has not been documented.[12]
Weaning occurs at 42 days. Young emerge from dens at about 50 days but may be moved by their mother before this.[12] In northwestern Maine, kits were active but poorly coordinated at 7 to 8 weeks, gaining coordination by 12 to 15 weeks. Young reach adult body weight around 3 months.[36]
Kits generally stay in the company of their mother through the end of their first summer, and most disperse in the fall.[12] The timing of juvenile dispersal is not consistent throughout American marten's distribution, ranging from early August to October.[12] In south-central Yukon, young-of-the-year dispersed from mid-July to mid-September, coinciding with the onset of female estrus.[23] Observations from Yukon[23] suggest that juveniles may disperse in early spring.
American marten are opportunistic predators, influenced by local and seasonal abundance and availability of potential prey.[36] They require about 80 cal/day while at rest, the equivalent of about 3 voles (Microtus, Myodes, and Phenacomys spp.).[28] Voles dominate diets throughout the American marten's geographic range,[36] though larger prey—particularly snowshoe hares and American red squirrels—may be important, particularly in winter.[33][42] Red-backed voles (Myodes spp.) are generally taken in proportion to their availability, while meadow voles (Microtus' spp.) are taken in excess of their availability in most areas. Deer mice (Peromyscus maniculatus), shrews (Soricidae), birds, and carrion are generally eaten less than expected, but may be important food items in areas lacking alternative prey species.[12][43]
American marten diet may shift seasonally[26][44][33][37][45] or annually.[26][38] Generally, diet is more diverse in summer than winter, with summer diets containing more fruit, nuts, vegetation, and insects.[46] Diet is generally more diverse with the American marten's distribution compared to Pacific marten's,[36] though there is high diversity in the Pacific states. American marten exhibit the least diet diversity in the subarctic, though diversity may also be low in areas where the diet is dominated by large prey species (e.g., snowshoe hares or red squirrels).[47]
American marten may be important seed dispersers; seeds generally pass through the animal intact, and seeds are likely germinable. One study from Chichagof Island, southeast Alaska, found that Alaska blueberry (Vaccinium alaskensis) and oval leaf huckleberry (V. ovalifolium) seeds had higher germination rates after passing through the gut of American marten compared to seeds that dropped from the parent plant. Analyses of American marten movement and seed passage rates suggested that American marten could disperse seeds long distances: 54% of the distances analyzed were>0.3-mile (0.5 km).[48]
American marten in captivity may live for 15 years. The oldest individual documented in the wild was 14.5 years old. Survival rates vary by geographic region, exposure to trapping, habitat quality, and age. In an unharvested population in northeastern Oregon, the probability of survival of American marten ≥9 months old was 0.55 for 1 year, 0.37 for 2 years, 0.22 for 3 years, and 0.15 for 4 years. The mean annual probability of survival was 0.63 for 4 years.[49] In a harvested population in east-central Alaska, annual adult survival rates ranged from 0.51 to 0.83 over 3 years of study. Juvenile survival rates were lower, ranging from 0.26 to 0.50.[31] In Newfoundland, annual adult survival was 0.83. Survival of juveniles from October to April was 0.76 in a protected population, but 0.51 in areas open to snaring and trapping.[29] In western Quebec, natural mortality rates were higher in clear-cut areas than in unlogged areas.[50]
American marten are vulnerable to predation from raptors and other carnivores. The threat of predation may be an important factor shaping American marten habitat preferences, a hypothesis inferred from their avoidance of open areas and behavioral observations of the European pine marten (Martes martes).[12] Specific predators vary by geographic region. On Newfoundland, red foxes (Vulpes vulpes) were the most frequent predator, though coyote (Canis latrans) and other American marten were also responsible for some deaths.[29] In deciduous forests in northeastern British Columbia, most predation was attributed to raptors.[27] Throughout the distribution of American marten, other predators include the great horned owl (Bubo virginianus), bald eagle (Haliaeetus leucocephalus), golden eagle (Aquila chrysaetos), bobcat (Lynx rufus) Canada lynx (L. canadensis), mountain lion (Puma concolor),[13][41] fisher (Pekania pennanti), wolverine (Gulo gulo), grizzly bear (Ursus arctos horribilis), American black bear (U. americanus), and grey wolf (C. lupus).[34]
The fur of the American marten is shiny and luxuriant, resembling that of the closely related sable (Martes zibellina). At the turn of the twentieth century, the American marten population was depleted due to the fur trade. The Hudson's Bay Company traded in pelts from this species among others. Numerous protection measures and reintroduction efforts have allowed the population to increase, but deforestation is still a problem for the marten in much of its habitat. American marten are trapped for their fur in all but a few states and provinces where they occur.[36] The highest annual take in North America was 272,000 animals in 1820.[28]
Trapping is a major source of American marten mortality in some populations[31][50] and may account for up to 90% of all deaths in some areas.[12] Overharvesting has contributed to local extirpations.[51] Trapping may impact population density, sex ratios and age structure.[12][28][36] Juveniles are more vulnerable to trapping than adults,[29][51] and males are more vulnerable than females.[12][29] American marten are particularly vulnerable to trapping mortality in industrial forests.[36]
Other sources of mortality include drowning,[39] starvation,[52] exposure,[49] choking, and infections associated with injury.[29] During live trapping, high mortality may occur if individuals become wet in cold weather.[13]
American marten host several internal and external parasites, including helminths, fleas (Siphonaptera), and ticks (Ixodida).[28] American marten in central Ontario carried both toxoplasmosis and Aleutian disease, but neither affliction was suspected to cause significant mortality.[41] High American marten mortality in Newfoundland was caused by encephalitis.[52]
This article incorporates public domain material from Martes americana. United States Department of Agriculture.
{{cite web}}: CS1 maint: archived copy as title (link) The American marten (Martes americana), also known as the American pine marten, is a species of North American mammal, a member of the family Mustelidae. The species is sometimes referred to as simply the pine marten. The name "pine marten" is derived from the common name of the distinct Eurasian species, Martes martes. It is found throughout Canada, Alaska, and parts of the northern United States. It is a long, slender-bodied weasel, with fur ranging from yellowish to brown to near black. It may be confused with the fisher (Pekania pennanti), but the marten is lighter in color and smaller. Identification of the marten is further eased by a characteristic bib that is a distinctly different color than the body. Sexual dimorphism is pronounced, with males being much larger.
The diet is omnivorous and varies by season, but relies chiefly on small mammals like voles. They are solitary except during the mid-summer breeding season. Embryonic implantation is delayed until late winter, however, with a litter of 1–5 kits born the following spring. Young stay with the mother in a constructed den until the fall and reach sexual maturity by one year old.
Their sable-like fur made them a thoroughly trapped species during the height of the North American fur trade. Trapping peaked in 1820, and populations were depleted until after the turn of the century. Populations have rebounded since, with them being considered a species of least-concern by the IUCN; however, they remain extirpated from some areas of the Northeast, and of the 7 subspecies, one is threatened.
Amerika marteso (Martes americana) estas marteso de Nordameriko. Ĝi havas delikatan flavbrunan ĝis nigran hararon; makuloj sur la gorĝo kaj brusto kremkoloraj ĝis oranĝaj.
Amerika marteso (Martes americana) estas marteso de Nordameriko. Ĝi havas delikatan flavbrunan ĝis nigran hararon; makuloj sur la gorĝo kaj brusto kremkoloraj ĝis oranĝaj.
La marta americana (Martes americana) es un miembro norteamericano de la familia Mustelidae. A veces es llamada marta de los pinos, nombre también usado para referirse a la especie europea Martes martes. Se distingue de la marta pescadora (Martes pennanti) en que tiene un tamaño menor, y que tiene un pelaje marrón más claro.[2]
La especie es principalmente nocturna, y pasa la mayor parte de su tiempo sobre los árboles, aunque caza principalmente en el suelo.[2] Posee un cuerpo esbelto, cubierto de un pelaje marrón brillante, con una mancha más clara en la garganta, una cola larga y un hocico puntiagudo,[3] y tienen una cola peluda, que utilizan para balancearse en los árboles.[4] Los machos miden entre 560 y 680 mm, pesando unos 1300 g. Las hembras son ligeramente más pequeñas, y pesan unos 850 g.[2]
El animal es omnívoro, aunque se alimenta principalmente carne, sobre todo de mamíferos pequeños, prefiriendo las ardillas rojas (Tamiasciurus hudsonicus). También comen peces, anfibios, insectos y aves, y fruta cuando esta está disponible.[4] Cazan preferentemente de noche, asestando una poderosa mordida en el cuello de sus presas.[2]
Son animales solitarios, excepto durante la época de apariamento.[2] Viven en territorios de 13 a 40 kilómetros cuadrados.[4]
Los machos defienden su territorio agresivamente de otros machos, apareándose con varias hembras. Durante el estro las hembras usan marcas de esencia para informar de su condición a los machos.[2]
Los apareamientos son estivales. El ritual de apareamiento incluye lucha, y juegos. La hembra puede tener de uno a cuatro periodos de receptividad, que duran de uno a cuatro días cada uno, separados una o dos semanas cada uno. El periodo de embarazo es de unos 250 días, pero ocurre una diapausa embriónica prolongada, tras la cual el embrión se desarrolla en sólo 28 días,[2] lo que le permite nacer en primavera, cuando las condiciones atmosféricas son más favorables, y hay más alimento disponible.[4]
Nacen de 1 a 5 crías ciegas por camada. Las crías crecen rápido, abriendo los ojos a los 39 días. El destete ocurre a los 42 días, y alcanzan su tamaño adulto a los 3 meses y medio.[2]
Alcanzan la madurez sexual entre los 15 y 24 meses de edad. Viven hasta 17 años en cautiverio, siendo las hembras fértiles hasta los 12 años.[2]
La especie vive en bosques de coníferas o mixtos desde Alaska y Canadá, hasta el norte de Nueva Inglaterra,[5][6][7] a través de las Rocallosas. La tala y destrucción de los bosques han reducido sus números,[1] aunque se mantiene en mejor condición que la marta pescadora. La subespecie Martes americana atrata (marta americana de Newfoundland) se considera en peligro.[8] Existen programas de reintroducción en Minnesota y Ontario.[2]
El mayor riesgo a su conservación es la pérdida de su hábitat debido al cambio del uso del suelo.[1] La tala los afecta especialmente, dependen de los bosques para su refugio y alimentación.[4]
Aún pueden ser cazadas legalmente por su piel en la mayoría de los estados del Sur de Estados Unidos. Esta práctica llevó a la especie hasta casi la extinción principios del siglo XX,[1] pues fueron cazadas indiscriminadamente durante los siglos XVIII y XIX.[4]
Hasta 1853 se reconocían dos especies norteamericanas de marta, Martes caurina y Martes americana. Subsecuentemente, se encontró que ambas especies coexistían en Montana y la Columbia Británica, por lo que se unieron bajo la denominación M. americana, reconociéndose ambos grupos como subespecies. Sin embargo, se ha sugerido basado en análisis genéticos, que las subespecies caurina y americana son de hecho dos especies distintas, aunque la mayoría de las autoridades científicas las reconocen como parte de la misma especie.[9]
La especie posee actualmente 13 subespecies reconocidas:[10]
Datos: Q322145
Multimedia:
Especies: Martes americana
La marta americana (Martes americana) es un miembro norteamericano de la familia Mustelidae. A veces es llamada marta de los pinos, nombre también usado para referirse a la especie europea Martes martes. Se distingue de la marta pescadora (Martes pennanti) en que tiene un tamaño menor, y que tiene un pelaje marrón más claro.
Martes americana Martes generoko animalia da. Artiodaktiloen barruko Mustelinae azpifamilia eta Mustelidae familian sailkatuta dago.
Martes americana Martes generoko animalia da. Artiodaktiloen barruko Mustelinae azpifamilia eta Mustelidae familian sailkatuta dago.
Amerikannäätä (Martes americana) on Pohjois-Amerikan pohjois- ja länsiosista kotoisin oleva melko pienikokoinen nisäkäs, joka kuuluu näätien sukuun ja näätäeläinten heimoon. Se on pienempi ja vaaleampi kuin lähisukulaisensa kanadannäätä.[3][4]
Amerikannäädällä on pitkänomainen, hoikka keho, matalat jalat ja tuuhea häntä, jonka pituus on noin kolmasosan sen koko pituudesta.[3][4][5] Uros on naarasta kookkaampi: sen pituus on 36–45 senttimetriä ja paino 470–1300 grammaa. Naaras on yleensä vain 32–40 senttimetrin pituinen ja 280–850 gramman painoinen.[3]
Amerikannäädällä on kiilanmuotoinen pää, lyhyt kuono ja suuret, pyöreähköt korvat. Käpälissä on viisi varvasta, joissa on käyrät ja terävät kynnet.[5] Tuuhea, kiiltävä turkki on selästä vaaleanruskea, rinnasta kermanvaalea tai oranssi, päästä harmaa sekä jaloista ja hännästä tummanruskea.[3][4] Kummankin silmän sisäkulmasta otsalle ulottuu musta pystyjuova.[4]
Amerikannäätä on kotoisin Pohjois-Amerikan pohjoisosista. Sen levinneisyysalue ulottuu Alaskasta Yhdysvaltojen koillisreunalle ja käsittää lähes koko Kanadan metsävyöhykkeen. Mantereen länsiosissa se on levittäytynyt etelään Kalliovuoria pitkin Sierra Nevadaan asti.[1] Metsien häviäminen on romahduttanut sen kannan levinneisyysalueen kaakkoisreunalla, missä se oli melko yleinen vielä Britannian siirtomaavallan aikana. Minnesotassa ja Ontariossa kantoja on yritetty elvyttää palautusistutuksilla.[3]
Amerikannäätää tavataan eniten pohjoisissa aarniometsissä, niin alavilla mailla kuin vuoristoissakin.[3] Se suosii erityisesti vanhoja havu- ja sekametsiä, joiden pohjakerroksessa on runsaasti kantoja, puunjuuria ja kaatuneita puita.[4] Se tekee reviirilleen yleensä useita pesiä onttoihin puunrunkoihin, kallionhalkeamiin tai toisten eläinten hylkäämiin pesäkoloihin, ja vuoraa ne lehdillä, sammalella ja muilla kasvinosilla.[3][4][5]
Amerikannäätä ei siedä muita oman sukupuolensa yksilöitä omalla reviirillään.[4] Reviirin koko vaihtelee suuresti ympäristön ja ravinnon saatavuuden mukaan: uroksilla sen pinta-ala on noin 8 neliökilometriä ja naarailla 2 neliökilometriä.[3] Näätä koluaa alueen läpi kerran 8–10 päivässä pyyntiretkillään.[4]
Amerikannäätä elää yleensä yksinään, vaikka luonnossa tavataankin silloin tällöin näätäpariskuntia poikasineen.[3] Se on luonteeltaan arka mutta utelias ja liikkuu etupäässä öisin.[4] Se pysyttelee päivät pesässään ja saalistaa auringonlaskujen ja -nousujen aikoihin, jolloin myös sen saaliseläimet ovat liikkeellä. Se on aktiivinen läpi talven ja kaivaa lumihankeen käytäviä löytääkseen pikkunisäkkäitä ravinnokseen.[3][4]
Amerikannäätä kiipeilee taitavasti ja viettää suuren osan elämästään puussa, vaikka saalistaakin enimmäkseen maassa. Se osaa myös uida ja sukeltaa hyvin. Muiden näätäeläinten tavoin se viestii lajitovereilleen vartalon asennoilla, ääntelemällä ja jättämällä voimakkaita hajujälkiä ympäristöönsä.[3]
Amerikannäädän lisääntymiskausi kestää kesäkuusta elokuuhun, minä aikana naaraalla on yhdestä neljään 1–4 päivän mittaista kiimajaksoa. Kiiman aikana naaras jättää ympäristöönsä hajujälkiä merkiksi seksuaalisuudesta valmiudestaan. Kosiskelumenot kestävät pitkään ja niihin sisältyy piehtarointia, leikkimistä ja painia.[3] Sekä urokset että naaraat saattavat paritella useiden kumppaneiden kanssa lisääntymiskauden aikana.[4]
Raskaus kestää 220–275 päivää, vaikka varsinainen kantoaika on vain 28 päivää. Tämä johtuu siitä, että hedelmöityneet munasolut kiinnittyvät kohdunseinämään viiveellä – yleensä vasta helmikuussa. Naaras synnyttää pesäänsä 1–5 sokeaa poikasta maaliskuun lopussa tai huhtikuun alussa.[3] Uros ei auta naarasta poikasten hoivaamisessa.[4] Poikasten silmät avautuvat noin 40 päivän kuluttua syntymästä ja pian tämän jälkeen ne vieroittuvat emostaan.[3] Ne poistuvat emonsa reviiriltä loppukesästä tai alkusyksystä perustaakseen oman reviirinsä.[4]
Amerikannäätä on kasvanut täyteen mittaansa noin 3,5 kuukauden iässä ja saavuttaa sukukypsyyden 15–24 kuukauden iässä. Vankeudessa se voi elää jopa 17 vuoden ikäiseksi, mutta luonnossa keskimääräinen elinikä on todennäköisesti huomattavasti lyhyempi.[3]
Amerikannäätä on kaikkiruokainen petoeläin, joka pyydystää ruoakseen pääasiassa oravia, jyrsijöitä ja muita pikkunisäkkäitä. Usein sen voi nähdä ajattamassa mielisaalistaan punaoravia puunoksalta toiselle.[3] Lisäksi se syö lintuja, hyönteisiä ja haaskoja ja etenkin syyskesällä marjoja ja siemeniä.[3][5] Se tappaa saaliinsa nopealla, voimakkaalla puraisulla niskaan.[3]
Amerikannäätä on pysynyt lajina elinvoimaisena, vaikka sitä metsästetään paljon arvokkaan turkkinsa vuoksi. Metsästyksen lisäksi sitä uhkaavat metsänhakkuut. Sillä ei ole varsinaisesti luonnollisia vihollisia.[3]
Amerikannäätä (Martes americana) on Pohjois-Amerikan pohjois- ja länsiosista kotoisin oleva melko pienikokoinen nisäkäs, joka kuuluu näätien sukuun ja näätäeläinten heimoon. Se on pienempi ja vaaleampi kuin lähisukulaisensa kanadannäätä.
Martre d'Amérique, Martre des Hurons
La Martre d'Amérique (Martes americana) est une espèce de mammifères terrestres de la famille des Mustélidés. Cette martre se rencontre en Amérique du Nord.
La martre d'Amérique a un long corps mince couvert de fourrure brun brillant avec une gorge de couleur plus claire, une longue queue touffue et un museau pointu. Le mâle présente une longueur (tête-corps) de 36 à 45 cm de long, prolongé par une queue de 15 à 23 cm. Son poids varie entre 470 et 1 300 g alors que la femelle, plus petite, ne dépasse pas les 850 g. La martre est digitigrade, ce qui signifie qu'elle marche sur le bout de ses doigts et n'appuie pas sa patte au complet sur le sol. À l'instar de celles des chats, ses griffes sont semi-rétractable, ce qui l'aide à grimper dans les arbres. Elle a également de très grandes pattes par rapport au poids corporel, ce qui lui permet de marcher sur la neige, et ce aussi légère que de la fine poudreuse. Cela donne à cette espèce un net avantage dans les zones qui bénéficient de fortes neiges.
La martre d'Amérique diffère du Pékan de par sa taille plus petite et de son pelage brun plus clair sur la poitrine.
L'animal est omnivore, préférant capturer et manger les petits mammifères, en particulier les écureuils roux américains, mais consomme facilement des poissons, grenouilles, insectes, charognes, ainsi que des fruits et de la végétation, lorsqu'il y en a. Il cherche sa nourriture aussi bien au sol que dans les arbres et sait par ailleurs très bien nager. La martre des hurons est essentiellement active la nuit, tôt le matin et en fin d'après-midi. Elle est généralement solitaire en dehors de la saison d'accouplement.
Les mâles défendent un territoire de huit kilomètres carrés en moyenne, et peuvent être très agressifs envers les autres mâles. Le territoire des femelles est nettement plus petit et atteint 2,3 kilomètres carrés en moyenne. Les martres d'Amérique n'hibernent pas, mais se rendent plus au sud ou plus bas en altitude durant l'hiver.
L'accouplement se produit au cours de l'été, mais l'implantation du blastocyste fécondé est retardée (dormance, diapause) et de 1 à 5 jeunes naissent au printemps suivant dans un nid situé dans un arbre creux ou dans une cavité rocheuse. Les petits, qui naissent aveugles, ouvrent les yeux après 40 jours, sont sevrés au bout de six semaines et deviennent indépendants à l'âge de trois mois et demi. Ils atteignent leur maturité sexuelle durant leur deuxième année.
La martre d'Amérique vit dans les forêts de conifères d'Alaska et du Canada, ainsi que, plus au sud, dans les montagnes Rocheuses, dans la région des Grands Lacs et en Nouvelle-Angleterre.
Cette espèce a été décrite pour la première fois en 1806 par le naturaliste britannique William Turton (1762-1835).
Selon Mammal Species of the World (version 3, 2005) (4 juin 2013)[7] et Catalogue of Life (4 juin 2013)[8] :
La fourrure de la martre d'Amérique est brillante, ressemblant à celle de la Zibeline. Au tournant du vingtième siècle, les populations de martres d'Amérique ont été décimées en raison du commerce des fourrures. La Compagnie de la Baie d'Hudson a commercialisé les peaux de cette espèce, parmi d'autres.
La martre peut être un animal de compagnie joueur quand elle est élevée par les hommes et que les jeunes sont nourris à la bouteille. Cependant, certaines provinces canadiennes et États américains rendent un permis obligatoire pour détenir un tel animal. Cette exigence vise généralement à décourager la population à retirer des espèces sauvages de leur habitat naturel.
De nombreuses mesures de protection et efforts de réintroduction ont permis à la population d'augmenter, mais la déforestation est encore un problème pour la martre dans une grande partie de son habitat. La chasse de la martre d'Amérique est actuellement légale dans certaines zones au cours d'une courte saison de chasse.
C'est une des nombreuses espèces menacées par la fragmentation forestière et victime de mortalité par collision avec les véhicules[9]
Si la chasse et la destruction des forêts ont réduit son habitat, elle reste plus abondante que le pékan. La sous-espèce vivant sur l'île de Terre-Neuve (Martes americana atrata) est considérée comme étant en danger.
Martre d'Amérique, Martre des Hurons
La Martre d'Amérique (Martes americana) est une espèce de mammifères terrestres de la famille des Mustélidés. Cette martre se rencontre en Amérique du Nord.
Američka kuna (Martes americana) sjevernoamerički je član roda Martes unutar potporodice Mustelinae svrstane u porodicu Mustelidae. Razlikuje se od kune ribolovca (Martes pennanti) po svojoj manjoj veličini, smeđoj boji krzna i nepravilno oblikovanom uzorku na prsima koji je svijetle boje.
Američka kuna živi u zrelim crnogoričnim ili miješanim šumama Aljaske i Kanade, te sjeveru Stjenjaka. Hvatanje u zamke i krčenje njenog prirodnog staništa smanjili su broj populacije, no brojnija je od populacije kune ribolovca. Newfoundlandska podvrsta ove životinje (Martes americana atrata) smatra se ugroženom.
Američka kuna ima duguljasto i vitko tijelo prekriveno sjajnim smeđim krznom sa svijetlije obojenim vratom, dugim kitnjastim repom i zašiljenom njuškom. Njene se kandže daju djelomično uvući, pomažući joj pritom pri penjanju na drveće. Također ima prilično velike jastučiće na stopalima u razmjeru na njenu tjelesnu težinu što joj dopušta hodanje u snijegu. Ovo pruža američkoj kuni prednost u područjima s teškim snijegom.
Krzno američke kune sjajno je i raskošno, nalikujući na krzno njenoj rođaka samura. Na prijelazu dvadesetog stoljeća, populacija američke kune desetkovana je zbog trgovine njenim krznom. Brojne mjere zaštite i uvođenje jedinki u prirodna staništa dovele su do oporavka populacije, no krčenje šuma i dalje predstavlja problem populacijama američke kune u većini njenog staništa. Lov na američku kunu trenutačno je zakonit u određenim područjima tijekom kratkih sezona lova.
Američka je kuna većinom aktivna danju, rano ujutro ili kasno poslije podne. U pravilu je samotna životinja izvan sezone parenja. Mužjaci brane svoj teritorij i mogu biti veoma agresivni prema mužjacima svoje vrste. Parenje se ovdje tijekom ljeta, no usađivanje oplođenog jajašca odgađa se te se sljedeće proljeće kote jedno do petero mladunaca.
Ova je životinja svejed, preferirajući hvatanje i prehranjivanje malenim sisavcima, posebice američkim crvenim vjevericama (Tamiasciurus hudoniscus), no spremno jede i ribu, žabe, kukce, strvinu, voće i ostalu hranu biljnog podrijetla kada joj je dostupna.
U Wikimedijinu spremniku nalazi se članak na temu: Martes americana
Wikivrste imaju podatke o: američkoj kuni Američka kuna (Martes americana) sjevernoamerički je član roda Martes unutar potporodice Mustelinae svrstane u porodicu Mustelidae. Razlikuje se od kune ribolovca (Martes pennanti) po svojoj manjoj veličini, smeđoj boji krzna i nepravilno oblikovanom uzorku na prsima koji je svijetle boje.
La martora americana (Martes americana) è un membro nordamericano della famiglia Mustelidae. Chiamata talvolta martora dei pini, bisognerebbe notare che il termine martora dei pini viene anche usato per indicare una specie separata di martora dell'Europa. Si differenzia dal pescatore (Martes pennanti) in quanto è più piccola di dimensioni ed ha un pelame solitamente bruno con una macchia sul petto di forma irregolare di colore più chiaro.
Alcuni autori ritengono che la popolazione che vive negli Stati Uniti occidentali debba essere considerata una specie distinta e danno a quest'animale il nome scientifico di Martes caurina.
Questa martora vive nelle foreste di conifere mature e in quelle miste di Alaska e Canada, spingendosi a sud attraverso le Montagne Rocciose. L'intrappolamento e la distruzione dell'habitat forestale hanno ridotto il suo numero, ma è ancora molto più abbondante del più grande pescatore. La sottospecie di Terranova di questo animale (Martes americana atrata) viene considerata minacciata.
La martora americana ha un lungo corpo snello ricoperto da una pelliccia brunastra lucente con una gola di colore più chiaro, una lunga coda folta ed un muso appuntito. Come quelli dei gatti, i suoi artigli sono semi-retrattili e l'aiutano nell'arrampicarsi sugli alberi. Ha anche cuscinetti plantari molto grandi rispetto al peso corporeo, che le consentono di camminare sulla neve dura. Questa peculiarità permette alla martora un notevole vantaggio nelle aree che ricevono pesanti nevicate.
Quest'animale è onnivoro, preferendo catturare e mangiare piccoli mammiferi, soprattutto lo scoiattolo rosso americano (Tamiasciurus hudsonicus), ma consuma facilmente pesci, rane, insetti, carogne, frutti e altri tipi di vegetali, quando sono disponibili. È più attiva di notte, di primo mattino o di pomeriggio tardi. Al di fuori della stagione degli amori è solitamente solitaria. I maschi difendono un territorio che va da 2,5 a 7,7 chilometri quadrati e possono essere molto aggressivi nei confronti degli altri maschi. L'accoppiamento avviene durante l'estate, ma l'impianto dell'uovo fecondato è ritardato (impianto ritardato [1]) e i «cuccioli», da 1 a 5, nascono la primavera seguente in una tana in un albero cavo o in una cavità tra le rocce.
Le martore americane possono divenire animali domestici molto giocherelloni quando vengono catturate da piccole e nutrite con il biberon. Comunque, in diverse province (Canada) e stati (Stati Uniti) è necessario ottenere un determinato permesso per tenere in una residenza privata animali selvatici. Tra le varie legislazioni che applicano questa legge ricordiamo il Fish and Wildlife Act e il Wildlife Act. I permessi ottenuti possono comprendere un permesso di riabilitazione o un permesso di mantenimento in cattività. È una cosa normale per i governi e per le organizzazioni naturalistiche scoraggiare la gente a rimuovere animali selvatici dal suo ambiente naturale, salvo nei casi in cui la loro sopravvivenza sia minacciata.
La pelliccia della martora americana è lucente e folta, ricordando quella dello strettamente imparentato zibellino. Agli inizi del ventesimo secolo, la popolazione della martora americana si era molto impoverita a causa del commercio delle pellicce. La Compagnia della Baia di Hudson commerciava pelli come queste, oltre a quelle di altri animali. Numerose misure protettive e sforzi di reintroduzione hanno permesso alla popolazione di crescere, ma la deforestazione è ancora un problema per la martora in gran parte del suo habitat. La caccia alla martora americana è attualmente legale in certe aree durante una breve stagione venatoria.
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La martora americana (Martes americana) è un membro nordamericano della famiglia Mustelidae. Chiamata talvolta martora dei pini, bisognerebbe notare che il termine martora dei pini viene anche usato per indicare una specie separata di martora dell'Europa. Si differenzia dal pescatore (Martes pennanti) in quanto è più piccola di dimensioni ed ha un pelame solitamente bruno con una macchia sul petto di forma irregolare di colore più chiaro.
Alcuni autori ritengono che la popolazione che vive negli Stati Uniti occidentali debba essere considerata una specie distinta e danno a quest'animale il nome scientifico di Martes caurina.
Questa martora vive nelle foreste di conifere mature e in quelle miste di Alaska e Canada, spingendosi a sud attraverso le Montagne Rocciose. L'intrappolamento e la distruzione dell'habitat forestale hanno ridotto il suo numero, ma è ancora molto più abbondante del più grande pescatore. La sottospecie di Terranova di questo animale (Martes americana atrata) viene considerata minacciata.
La martora americana ha un lungo corpo snello ricoperto da una pelliccia brunastra lucente con una gola di colore più chiaro, una lunga coda folta ed un muso appuntito. Come quelli dei gatti, i suoi artigli sono semi-retrattili e l'aiutano nell'arrampicarsi sugli alberi. Ha anche cuscinetti plantari molto grandi rispetto al peso corporeo, che le consentono di camminare sulla neve dura. Questa peculiarità permette alla martora un notevole vantaggio nelle aree che ricevono pesanti nevicate.
Quest'animale è onnivoro, preferendo catturare e mangiare piccoli mammiferi, soprattutto lo scoiattolo rosso americano (Tamiasciurus hudsonicus), ma consuma facilmente pesci, rane, insetti, carogne, frutti e altri tipi di vegetali, quando sono disponibili. È più attiva di notte, di primo mattino o di pomeriggio tardi. Al di fuori della stagione degli amori è solitamente solitaria. I maschi difendono un territorio che va da 2,5 a 7,7 chilometri quadrati e possono essere molto aggressivi nei confronti degli altri maschi. L'accoppiamento avviene durante l'estate, ma l'impianto dell'uovo fecondato è ritardato (impianto ritardato [1]) e i «cuccioli», da 1 a 5, nascono la primavera seguente in una tana in un albero cavo o in una cavità tra le rocce.
Le martore americane possono divenire animali domestici molto giocherelloni quando vengono catturate da piccole e nutrite con il biberon. Comunque, in diverse province (Canada) e stati (Stati Uniti) è necessario ottenere un determinato permesso per tenere in una residenza privata animali selvatici. Tra le varie legislazioni che applicano questa legge ricordiamo il Fish and Wildlife Act e il Wildlife Act. I permessi ottenuti possono comprendere un permesso di riabilitazione o un permesso di mantenimento in cattività. È una cosa normale per i governi e per le organizzazioni naturalistiche scoraggiare la gente a rimuovere animali selvatici dal suo ambiente naturale, salvo nei casi in cui la loro sopravvivenza sia minacciata.
La pelliccia della martora americana è lucente e folta, ricordando quella dello strettamente imparentato zibellino. Agli inizi del ventesimo secolo, la popolazione della martora americana si era molto impoverita a causa del commercio delle pellicce. La Compagnia della Baia di Hudson commerciava pelli come queste, oltre a quelle di altri animali. Numerose misure protettive e sforzi di reintroduzione hanno permesso alla popolazione di crescere, ma la deforestazione è ancora un problema per la martora in gran parte del suo habitat. La caccia alla martora americana è attualmente legale in certe aree durante una breve stagione venatoria.
Amerikinė kiaunė (lot. Martes americana, angl. American Marten, vok. Fichtenmarder) – kiauninių šeimos plėšrus žinduolis.
Paplitusi Aliaskoje, Kanadoje spygliuočių ir mišriuose miškuose.
Šis straipsnis apie zoologiją yra nebaigtas. Jūs galite prisidėti prie Vikipedijos papildydami šį straipsnį.
Amerikas cauna (Martes americana) ir neliela auguma sermuļu dzimtas (Mustelidae) plēsējs, kas pieder caunu ģintij (Martes). Amerikas caunas tuvākā radiniece ir zivju cauna.
Amerikas caunai ir ļoti kvalitatīva kažokāda, un tās populācija medību iespaidā 20. gadsimtā tika iespaidīgi samazināta. Mūsdienās ir ieviesti dažādi sugas aizsardzības pasākumi, kas ļāvuši populācijai sākt atjaunoties.
Amerikas cauna dzīvo Ziemeļamerikas ziemeļu daļā, un tā ir sastopama gan Aļaskā, gan ASV teritorijās uz dienvidiem no Kanādas, gan Kanādā.[1] Amerikas caunas izplatības karti var apskatīt šeit. Kopumā caunas ir bieži sastopams dzīvnieks, bet Amerikas caunas Ņūfaundlendas pasugas (Martes americana atrata) izdzīvošana ir padraudēta.
Amerikas caunai ir garš, slaids ķermenis ar īsām kājām. Kažoks spožs, visbiežāk tumši brūnā krāsā, bet var būt arī gaiši dzeltens.[2] Pakakle ir nedaudz gaišāka. Toties aste un kājas ļoti tumšas, reizēm gandrīz melnas.[3] Ziemā kažoks ir biezs, vasarā plānāks.
Amerikas caunai ir gara, kupla aste un smalks, smails purniņš. Caunai ir asi un līki nagi, kurus tā spēj daļēji ievilkt. Pateicoties asajiem nagiem, cauna ir veikla kāpelētāja pa kokiem. Tai ir relatīvi lielas ķepas, un ziemā pēdu platā virsma notur caunas vieglo augumu virs sasalušā sniega. Gan priekškājām, gan pakaļkājām Amerikas caunai ir pieci pirksti. Spilventiņi gandrīz visu gadu klāti ar biezu, elastīgu matojumu. Galva nedaudz saplacināta, acis un ausis lielas, salīdzinot ar galvas izmēru.[2]
Amerikas caunas ir mazākās caunu ģintī (Martes). Kā visām caunām tēviņi ir lielāki par mātītēm. Ķermeņa garums tēviņiem ir 36—45 cm, astes garums 15—23 cm, svars 470—1300 g, bet mātītēm ķermeņa garums ir 32—40 cm, svars 280—850 g.
Amerikas cauna ir nakts dzīvnieks, uzsākot medības vēlu pēcpusdienā un ejot atpūsties agri no rīta. Dienu tā pavada savā migā, kas ierīkota koka dobumā vai akmeņu krāvumā. Amerikas cauna kā visas caunas ir vientuļniece, un viena ar otru satiekas tikai riesta laikā. Tēviņi savā starpā var būt ļoti neiecietīgi. Tēviņu teritorija ir apmēram 8 km², bet mātītes teritorija ir mazāka, tikai 2,3 km².[3]
Amerikas cauna ir ļoti izveicīga un ātra kāpelētāja kokos, tāpat kā vāveres tā spēj lekt no koka uz koku, dzenoties pakaļ iecienītajam upurim vāverei. Amerikas cauna spēj lecienā starp kokiem nolidot 18 metrus un viegli pēc tam turpināt skrējienu.[2]
Lai arī Amerikas cauna daudz laika pavada kokā, pamatā tā medī uz zemes.[3] Amerikas cauna ir visēdāja un apēdīs jebko, ko varēs nomedīt. Parasti cauna medī mazus dzīvniekus, īpaši Amerikas rudo vāveri (Tamiasciurus hudsonicus), bet tā medī arī grauzējus, zivis, vardes, kukaiņus, neatsakās no maitas un pie iespējas ēd augļus, ogas un riekstus.
Riests caunām ir vasarā, bet mazuļi dzimst nākamā gada pavasarī, jo mātītei ir embrioniskā diapauze un tā spēj atlikt embrija attīstību, patiesais mazuļu attīstības laiks ir 28 dienas.[3] Parasti piedzimst 1—5 akli, nevarīgi mazuļi. Māte tos zīda ar pienu 42 dienas.[3]
Amerikas cauna (Martes americana) ir neliela auguma sermuļu dzimtas (Mustelidae) plēsējs, kas pieder caunu ģintij (Martes). Amerikas caunas tuvākā radiniece ir zivju cauna.
Amerikas caunai ir ļoti kvalitatīva kažokāda, un tās populācija medību iespaidā 20. gadsimtā tika iespaidīgi samazināta. Mūsdienās ir ieviesti dažādi sugas aizsardzības pasākumi, kas ļāvuši populācijai sākt atjaunoties.
De Amerikaanse marter (Martes americana) is een Noord-Amerikaanse marterachtige. Hij lijkt op de Euraziatische boommarter, maar de Amerikaanse marter heeft een lichtgekleurde kop.
Amerikaanse marters worden 49 tot 68,2 cm lang en 400 tot 1600 gram zwaar. Hij heeft een lange, volle staart van 13,5 tot 24 cm. Hij heeft een bruinige vacht, met een blekere kop en donkere poten. Opvallend is zijn oranje tot geelbruine keelvlek. Mannetjes worden groter dan vrouwtjes.
Hij besteedt de meeste tijd op de grond, waar hij jaagt op zijn prooi. Zijn grote poten zorgen ervoor dat hij niet door eventuele sneeuw zakt. Andere belangrijke prooidieren zijn andere woelmuizen, Amerikaanse rode eekhoorn (Tamiasciurus hudsonicus) en Canadees vlieghoorntje (Glaucomys sabrinus). Ook konijnen, vogels en reptielen vormen een belangrijk onderdeel van zijn voedsel, en verder vult hij zijn dieet aan met insecten, aardwormen, eieren, aas, vruchten, kegels en honing. Soms begraaft hij de restjes.
De Amerikaanse marter is vooral in de ochtend- en avondschemering actief, maar ook 's nachts en op bewolkte dagen. Overdag schuilt hij in een boom- of rotsholte. Dit kan een natuurlijke holte zijn, een omgevallen stronk, een eekhoornnest of zelfs een spechtenhol. Hij maakt een nest van gras en bladeren.
Amerikaanse marters leven in bossen van Canada, in het westen tot Californië en de Rocky Mountains en in het oosten rond de Grote Meren, tot New York en New England. Hij heeft een voorkeur voor naaldwouden, met dode stammen, takken en bladeren. Hier leeft zijn voornaamste prooi, de noordelijke rosse woelmuis (Clethrionomys gapperi).
Bronnen, noten en/of referentiesDe Amerikaanse marter (Martes americana) is een Noord-Amerikaanse marterachtige. Hij lijkt op de Euraziatische boommarter, maar de Amerikaanse marter heeft een lichtgekleurde kop.
Multimedia w Wikimedia Commons Kuna amerykańska[3], kuna świerkowa (Martes americana) – północnoamerykański gatunek drapieżnego ssaka z rodziny łasicowatych. Jest bardzo podobna do kuny leśnej - różni się jedynie większymi stopami oraz jasnym pyszczkiem. Od kuny rybożernej, która również występuje w jej środowisku można ją odróżnić po wielkości (jest mniejsza) oraz kolorze futra (kuna świerkowa jest jaśniejsza, ma żółtawą plamę na podgardlu oraz wyżej wymieniony jasny pyszczek).
Kuny amerykańskie występują głównie w starych lasach iglastych i mieszanych w Kanadzie, na Alasce oraz w Północnej Nowej Anglii. Polowania oraz niszczenie lasów zredukowało liczbę jej osobników, ale nadal jest bardziej liczna niż kuna wodna. Nowofundlandzki podgatunek tej kuny, Martes americana atrata, jest zagrożony.
Podobna do innych kun - posiada długie, smukłe ciało pokryte błyszczącym, brązowawym futrem. Gardło jest żółtawe, pysk jaśniejszy. Ogon długi i puszysty. Podobnie do kotów, ma pół-wciągalne pazury, które ułatwiają wspinaczkę po drzewach. Mają również stosunkowo duże stopy, przydatne w bardziej ośnieżonych rejonach.
Jest to zwierzę wszystkożerne, preferuje jednak małe ssaki, szczególnie sosnowiórkę czerwoną (Tamiasciurus hudsonicus). Chętnie zjada również ryby, żaby, owady, padlinę oraz owoce i warzywa, kiedy są dostępne.
Kuna ta jest najbardziej aktywna wczesnym rankiem, późnym popołudniem i nocą. Poza sezonem godowym prowadzi samotniczy tryb życia. Samce chronią swojego terytorium o wielkości około 8 kilometrów kwadratowych, które pokrywają się z terytoriami samic, o wielkości około 2,5 kilometrów kwadratowych. Występuje duża agresja pomiędzy osobnikami tej samej płci.
Krycie odbywa się latem, ale występuje ciąża przedłużona i młode w liczbie jednego do pięciu rodzą się następnej wiosny, najczęściej w dziupli drzewa lub jamie skalnej.
Wyróżnia się kilkanaście podgatunków kuny amerykańskiej[4][1][3]:
Kuna amerykańska, kuna świerkowa (Martes americana) – północnoamerykański gatunek drapieżnego ssaka z rodziny łasicowatych. Jest bardzo podobna do kuny leśnej - różni się jedynie większymi stopami oraz jasnym pyszczkiem. Od kuny rybożernej, która również występuje w jej środowisku można ją odróżnić po wielkości (jest mniejsza) oraz kolorze futra (kuna świerkowa jest jaśniejsza, ma żółtawą plamę na podgardlu oraz wyżej wymieniony jasny pyszczek).
Biotop i zagrożeniaKuny amerykańskie występują głównie w starych lasach iglastych i mieszanych w Kanadzie, na Alasce oraz w Północnej Nowej Anglii. Polowania oraz niszczenie lasów zredukowało liczbę jej osobników, ale nadal jest bardziej liczna niż kuna wodna. Nowofundlandzki podgatunek tej kuny, Martes americana atrata, jest zagrożony.
WyglądPodobna do innych kun - posiada długie, smukłe ciało pokryte błyszczącym, brązowawym futrem. Gardło jest żółtawe, pysk jaśniejszy. Ogon długi i puszysty. Podobnie do kotów, ma pół-wciągalne pazury, które ułatwiają wspinaczkę po drzewach. Mają również stosunkowo duże stopy, przydatne w bardziej ośnieżonych rejonach.
PożywienieJest to zwierzę wszystkożerne, preferuje jednak małe ssaki, szczególnie sosnowiórkę czerwoną (Tamiasciurus hudsonicus). Chętnie zjada również ryby, żaby, owady, padlinę oraz owoce i warzywa, kiedy są dostępne.
Tryb życiaKuna ta jest najbardziej aktywna wczesnym rankiem, późnym popołudniem i nocą. Poza sezonem godowym prowadzi samotniczy tryb życia. Samce chronią swojego terytorium o wielkości około 8 kilometrów kwadratowych, które pokrywają się z terytoriami samic, o wielkości około 2,5 kilometrów kwadratowych. Występuje duża agresja pomiędzy osobnikami tej samej płci.
RozmnażanieKrycie odbywa się latem, ale występuje ciąża przedłużona i młode w liczbie jednego do pięciu rodzą się następnej wiosny, najczęściej w dziupli drzewa lub jamie skalnej.
A Marta-americana (Martes americana) é uma espécie de Marta nativa da América do Norte, é muito confundida com a marta-pescadora mas diferenciada por ser menor e mais clara.
A marta vive florestas de coníferas ou mistas no Alasca e no Canadá, e no sul do norte da Nova Inglaterra e pelas Montanhas Rochosas e Sierra Nevada.
A captura e desmatamento diminuíram a sua população mas ainda continua mais abundante que seu parente maior a marta-pescadora.
As martas são mais ativas na primavera e outono do que no inverno, pois nestas outras épocas é mais fácil achar comida.
Ambiente
O clima afeta muito no comportamento das martas, em temperaturas de -4° F a atividade da marta diminuí em 45%.
Durante o inverno as martas evitam o máximo de água possível, pois o frio de inverno pode congelar facilmente a mesma. A marta é adaptada a locomoção na neve profunda, pois em áreas aonde possuem martas-pescadoras ou lobos ela pode se locomover com mais velocidade.
A Marta-americana (Martes americana) é uma espécie de Marta nativa da América do Norte, é muito confundida com a marta-pescadora mas diferenciada por ser menor e mais clara.
Kuna americká (Martes americana) je zviera z čeľade lasicovité. Má červenkastohnedú srsť a krátke zavalité nohy. Dorastá do dĺžky 65 cm (vrátane chvosta). Korisť loví na zemi i na stromoch.
Žije v ihličnatých lesoch a veľmi zručne loví veverice v korunách stromov. Je rozšírená najmä v Kanade, Aljaške a v západnej časti USA.
Commons ponúka multimediálne súbory na tému Kuna americká
Wikidruhy ponúkajú informácie na tému Kuna americká
Tento článok týkajúci sa živočíchov je zatiaľ „výhonok“. Pomôž Wikipédii tým, že ho doplníš a rozšíriš. Kuna americká (Martes americana) je zviera z čeľade lasicovité. Má červenkastohnedú srsť a krátke zavalité nohy. Dorastá do dĺžky 65 cm (vrátane chvosta). Korisť loví na zemi i na stromoch.
Žije v ihličnatých lesoch a veľmi zručne loví veverice v korunách stromov. Je rozšírená najmä v Kanade, Aljaške a v západnej časti USA.
Amerikansk mård (Martes americana) är ett rovdjur i släktet mårdar som förekommer i Nordamerika.[2] Det finns stora likheter mellan den amerikanska och den europeiska mården och förstnämnda djur betraktas av några zoologer som underart till den sistnämnda.
Som hos de flesta mårddjur är kroppen långsträckt och smal med korta extremiteter. Pälsen har huvudsakligen en brun färg, huvudet är grå och extremiteterna samt svansen är svarta. Precis som den europeiska mården har djuret en krämfärgad fläck på halsens framsida men hos den amerikanska mården är denna betydligt mindre. Vuxna djur uppnår en kroppslängd av 32 till 45 cm och den yviga svansen är 14 till 23 cm lång. Hanar uppnår en vikt mellan 0,5 och 1,3 kg och honor mellan 0,3 och 0,9 kg.[3]
Den amerikanska mården förekommer i stora delar av Alaska och Kanada med undantag av de allra nordligaste områdena. Den lever också i USA i Klippiga bergen, vid de stora sjöarna och i New England. Populationerna i västra USA är inte sammanhängande. Arten når där i syd norra Kalifornien och Colorado. Habitatet utgörs huvudsakligen av skogar. Amerikansk mård är vanligast i täta barrskogar med några trädstammar liggande på marken.[1]
Under 1800-talet fanns amerikansk mård även i sydöstra USA.[4]
Denna art är i stort sett aktiv på natten. På dagen gömmer sig djuret i håligheter i träd, bergssprickor eller underjordiska bon som byggts av andra djur.[1] Den amerikanska mården letar sin föda på marken och i träd och är duktig på att simma och dyka.[3] Den håller ingen vinterdvala.[3]
Som hos de flesta mårddjur har varje individ ett revir. I genomsnitt är territoriet för hanar 8 kvadratkilometer och för honor 2,3 kvadratkilometer stort men storleken varierar beroende på habitat och tillgång till föda.[1] Dessa djur lever huvudsakligen ensamma men ibland iakttas par av olika kön som jagar tillsammans.[3] Reviret markeras med körtelvätska.[3]
Livslängden varar i naturen upp till tolv och i fångenskap upp till sjutton år.[3]
Amerikanska mårdar är allätare men huvuddelen av bytet består av gnagare och andra små däggdjur. Dessutom äter de fåglar, insekter, as och även frukt.[1] För att nå sina byten kan mården följa efter, sitta i ett bakhåll eller gräva fram de från deras underjordiska bon.[5]
Parningen sker under sommaren mellan juni och augusti men på grund av att ägget vilar en tid börjar den egentliga dräktigheten först i februari.[3] Dräktigheten varar i ungefär en månad och i mars eller april föder honan ett till fem (i genomsnitt 2,6) ungdjur. Dessa är till en början blinda och öppnar efter cirka 39 dagar ögonen. Efter 6 veckor sluter honan att dia ungarna och efter ungefär 3,5 månader är ungarna fullt utvecklade. Ungarna blir efter två år könsmogna.[3]
Honan fodrar lyan med torra växtdelar före ungarnas födelse. Ungarnas uppfostring skötas främst av honan. Ibland syns hannar tillsammans med en hona och hennes ungar.[3]
På grund av att djurets päls anses som värdefull blev den tidigare jagad. I några delar av utbredningsområdet minskade beståndet tydligt. I New England och Michigan räknades arten tidvis som utdöd men idag finns åter amerikanska mårdar där. I olika regioner finns skyddszoner för arten som allmänt inte räknas till de hotade arterna. Det beror väsentligen på det stora beståndet i Kanada.
Amerikansk mård (Martes americana) är ett rovdjur i släktet mårdar som förekommer i Nordamerika. Det finns stora likheter mellan den amerikanska och den europeiska mården och förstnämnda djur betraktas av några zoologer som underart till den sistnämnda.
Amerika sansarı (Martes americana), sansargiller (Mustelidae) familyasının Kuzey Amerika'da yaşayan bir türü. Balıkçı sansardan (Martes pennanti) farkı boyunun daha ufak olması ve genellikle göğsünde düzensiz bir şekilde daha açık renkli lekesi olan kahverengi kürkü olmasıdır.
Wikimedia Commons'ta Amerika sansarı ile ilgili çoklu ortam belgeleri bulunur. 
Wikispecies'te Amerika sansarı ile ilgili detaylı taksonomi bilgileri bulunur. 
Etçiller ile ilgili bu madde bir taslaktır. Madde içeriğini geliştirerek Vikipedi'ye katkıda bulunabilirsiniz. Amerika sansarı (Martes americana), sansargiller (Mustelidae) familyasının Kuzey Amerika'da yaşayan bir türü. Balıkçı sansardan (Martes pennanti) farkı boyunun daha ufak olması ve genellikle göğsünde düzensiz bir şekilde daha açık renkli lekesi olan kahverengi kürkü olmasıdır.
Куна американська має довге, струнке тіло, відносно великі округлі вуха, короткі кінцівки. Голова приблизно трикутна, ніс гострий. Ноги п'ятипалі (хоча перший палець редукований) і пальцеходячі. В зимовий період підошви ніг густо опушені. Довга, шовковиста, щільна шерсть в діапазоні кольорів від блідо-жовтуватого-бурого до майже чорного. Голова зазвичай світліша, ніж інші частини тіла, ноги і хвіст темніші. Горло від світло-солом'яного до яскраво-помаранчевого кольору, морда бліда. Хвіст довгий і пухнастий. Як кішка, має кігті, що напівубираються, щоб лазити по деревах. Куна американська також має відносно великі стопи, що корисно в снігових районах. Існує значний розкид індивідуального забарвлення, але між статями його нема. Гвардії волосся 31,8 до 44,5 мм в довжину і щільний підшерсток становить близько 25,4 мм. Влітку хутро більш тонку і грубе. Блискуче хутро американської куни високо цінується мисливцями.
Статевий диморфізм виражений: у самців в середньому на близько 15% більша, ніж у самиць довжина тіла і на 65% більша маса тіла. Існує значна різниця в розмірі в різних місцях по всьому континенту. Діапазони розмірів дорослого самця: голова і тіло довжиною від 360 до 450 мм, довжина хвоста, від 200 до 230 мм, маса 470 до 1250 гр. Для дорослих самиць: голова і тіло довжиною від 320 до 400 мм, хвіст від 180 до 200 мм, а вага від 280 до 850 г. Зубна формула: i 3/3, c 1/1, p 4/4, m 1/2 = 38. 2n=38 хромосом.
Американська куниці мешкає у більшій частині Північної Америки від Аляски протягом більшої частини лісової Канади до північного сходу США, і на південь вздовж північної Каліфорнії, й на півдні в гори Сьєрра-Невади і Скелясті гори. Живе в основному в старих, високих хвойних і змішаних лісах.
Лаштує гнізда в дуплах дерев або в колодах, скелястих ущелинах чи норах. Активний усі пори року, веде нічний спосіб життя (хоча також активний рано вранці й пізно ввечері) і почасти деревний, але витрачає багато часу на землі. Поза сезоном розмноження веде, як правило, але не завжди, відокремлене життя. Самці захищають домашню територію розміром близько 8 квадратних кілометрів, самиці — розміром близько 2,5 квадратних кілометрів, між територіями самців і самиць існує перекриття. Між особами однієї статі стосунки агресивні. Куна американська використовувати широкий спектр продуктів харчування. Поживою є головним чином гризуни та інші дрібні ссавці (Tamiasciurus, Glaucomys, Tamias, Peromyscus, Sorex), але також птахи та їхні яйця, рептилії, амфібії, дощові черви, комахи, падло, сезонно фрукти і ягоди. Мабуть, найбільшим звичайним видобутком куниці є заєць, Lepus americanus. Куна потребує близько 80 ккал/день або близько трьох мишей. Зимовий розподіл куни може регулювати більше наявність жертв, ніж інших чинники середовища проживання. Часто харчуючись під снігом, роблять тунелі вниз поруч з колодами і пнями.
Bubo virginianus, Aquila chrysaetos, Haliaeetus leucocephalus, Canis latrans, Vulpes vulpes, Lynx canadensis, Puma concolor, Martes pennanti — природні хижаки для куни американської. Жоден з них не спричиняє істотного впливу на чисельність куни.
Шлюбний сезон триває від 24 до 46 днів, як правило, відбувається в липні і серпні, але через ембріональну діапаузу малюки в кількості від одного до п'яти (в середньому 2.85) народжуються з середини березня до кінця квітня наступного року. Активна вагітність триває близько 27 днів. Таким чином, загальний термін вагітності становить від 220 до 276 днів. Варіація 56 днів в періоді вагітності ймовірно пов'язана з відмінностями в даті запліднення.
Через втрату місця існування, вид зник у багатьох південно-східних областях. На початок XX століття надмірне захоплення у пастки сильно виснажило куну американську на Алясці, в Канаді і північному заході Сполучених Штатів. Ареал цього виду скоротився.
Chồn thông châu Mỹ (Martes americana) là một loài động vật có vú trong họ Chồn, bộ Ăn thịt. Loài này được Turton mô tả năm 1806.[2]
Chồn thông Mỹ được phân bố rộng rãi ở miền bắc Bắc Mỹ. Từ Bắc vào Nam phạm vi của loài này kéo dài từ hạn phía bắc của dãy cây ở Bắc cực Alaska và Canada tới miền bắc New Mexico. Từ đông sang tây phạm vi phân bố của loài này kéo dài từ Newfoundland và tây nam đến quận Napa, California. Tại Canada và Alaska, phạm vi phân bố rộng lớn và liên tục. Ở miền Tây Hoa Kỳ, phạm vi loài này được giới hạn đến những dãy núi cung cấp môi trường sống ưa thích. Theo thời gian, sự phân bố của loài này đã thu gọn lại và mở rộng trong khu vực, với sự tuyệt chủng cục bộ và và tái lập thành công xảy ra tại khu vực Ngũ Đại hồ và một số khu vực của vùng Đông Bắc Mỹ. Chúng đã được đưa vào lại trong một số lĩnh vực tuyệt chủng đã xảy ra[4].
Loài chồn này sinh sống tại nơi rừng lá kim hoặc rừng hỗn hợp ở Alaska và Canada.[5] and south into Northern New England[6][7][8] và phía nam New England và thông qua dãy núi Rocky và Sierra Nevada. Nhóm nhỏ loài chồn này sinh sống ở trung Tây Minnesota và Wisconsin. Đánh bẫy và phá hoại sinh cảnh đã làm giảm số lượng của loài này. Phân loài Newfoundland của loài này (Martes americana atrata) được xem là bị đe dọa.
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Bài viết về các loài trong bộ thú ăn thịt này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Chồn thông châu Mỹ (Martes americana) là một loài động vật có vú trong họ Chồn, bộ Ăn thịt. Loài này được Turton mô tả năm 1806.
Martes americana
Turton, 1806
Американская куница[1] (лат. Martes americana) — редкий вид семейства куньих, внешне похож на лесную куницу.
Американская куница широко распространена на Североамериканском континенте. С севера на юг её ареал простирается от северной границы лесов арктической Аляски и Канады до северной части Нью-Мексико. С востока на запад её распространение простирается от Ньюфаундленда на юг и запад до Калифорнии. В Канаде и на Аляске американская куница расселена широко и непрерывно. В западной части Соединенных Штатов расселение ограничивается отдельными регионами, приуроченными горным цепям, на территории которых сложилась подходящая среда обитания. Популяция американской куницы была восстановлена в некоторых районах, где ранее отмечалось её сокращение.
Американская куница предпочитает обитать в хвойных или смешанных лесах Аляски и Канады. Небольшие группы куницы живут на среднем западе США в штатах Миннесота и Висконсин. Промысел и сокращение площади лесов, пригодных для обитания американской куницы, сократили её численность, но популяция ещё остаётся значительной. Считается, что один из подвидов (Martes americana atrata), обитающий в Ньюфаундленде, находится под угрозой исчезновения.
Американская куница имеет мягкий и густой мех, с вариацией цвета от бледно-жёлтого к красноватому и тёмно-коричневому. Шея животного бледно-жёлтая, а хвост и ноги тёмно-коричневые. На морде две чёрные линии, идущие вертикально от глаз. Пушистый длинный хвост составляет треть общей длины зверька. Самцы достигают длины тела от 36 см до 45 см при длине хвоста от 15 см до 23 см и веса от 470 г. до 1300 г. Самки меньше, длиной тела от 32 см и до 40 см и длиной хвоста от 13,5 см до 20 см и весят от 280 г. до 850 г.
Мало известно о повадках американской куницы, это типичный ночной и очень осторожный хищник.
Американская куница (лат. Martes americana) — редкий вид семейства куньих, внешне похож на лесную куницу.
아메리카담비(Martes americana)는 족제비과에 속하며 북아메리카에서 발견되는 담비류의 일종이다.[1] 솔담비 또는 소나무담비(pine marten)로도 불리지만, 유럽소나무담비와는 다른 종이다. 피셔보다 크기는 작고, 털 색은 더 밝다.
아메리카담비는 북아메리카 북부 지역에 널리 분포한다. 남북 방향으로 북쪽의 알래스카와 캐나다 북극 지역의 수목 한계선부터 남쪽으로 뉴멕시코주 북부 지역에 걸쳐 분포한다. 동서 방향으로 동쪽의 뉴펀들랜드섬부터 남서쪽의 캘리포니아주 나파 군에 이르는 지역에 분포한다.
13종의 아종이 알려져 있다.[2]
