Brown creepers primarily eat small arthropods such as spiders, psudoscorpions, and insects. Some insects they are known to eat include stinkbugs, fruit flies, and weevils. Brown creepers also eat seeds and other vegetable matter during the winter.
Brown creepers forage on live tree trunks and occasionally on large branches, but rarely on the ground. Large trees with thick bark tend to have larger densities of arthropods, and are therefor favored. Brown creepers probe tree trunks with their long curved bill. They move upward on the trunk, sometimes spiraling around it, working up the tree to within 1 to 3 m of the top. They then fly to the bottom of the trunk (or the trunk of another tree) and start over.
Animal Foods: insects; terrestrial non-insect arthropods
Plant Foods: seeds, grains, and nuts
Primary Diet: omnivore
Predators of brown creeper eggs, nestlings and adults include red squirrels (Tamiasciurus hudsonicus), domestic cats (Felis silvestris), northern flying squirrels (Glaucomys sabrinus), golden-mantled ground squirrels (Spermophilus lateralis), wood rats (genus Neotoma), and deer mice (Peromyscus maniculatus). Adults respond by freezing and flattening their bodies against a tree trunk.
Known Predators:
Anti-predator Adaptations: cryptic
Brown creepers are tiny birds with mottled feathers that make them nearly indistinguishable from a piece of bark when viewed at a distance. They have dark-brown upperparts that are heavily streaked with white on the head, back, scapulars (feathers covering the shoulder), and wings. They have a distinctive brown stripe through their eye and a white stripe above it. The underparts are white with red/brown lightly mixed in. They have a long, stiff tail with feathers that are used as props to help the birds move up and around the trunk of a tree.
Brown creepers are 11.7 to 13.5 cm long and weigh 7.2 to 9.9 g. Their wing chords measure 62.9 to 65.5 mm. A standard metabolic rate for brown creepers was measured at 4.0 kcal/24 hours.
Male and female brown creepers are very similar in appearance. Their decurved bills are one of the only ways to differentiate between the sexes. Males tend to have a slightly longer bill (1 to 2 mm longer) than females.
Range mass: 7.2 to 9.9 g.
Range length: 11.7 to 13.5 cm.
Sexual Dimorphism: sexes alike
Other Physical Features: endothermic ; bilateral symmetry
The maximum recorded age for a banded brown creeper was 4 years, 7 months. However, little is actually known about the lifespan/longevity of brown creepers.
Range lifespan
Status: wild: 4.6 (high) years.
Average lifespan
Status: wild: 55 months.
Brown creepers live in coniferous forests and mixed coniferous-deciduous forests. They require large trees (dead or alive) for foraging and nesting. In the Pacific Northwest, brown creepers also live in coniferous forests but avoid the forests of the Olympics where trees are much larger and more spread apart. In the Rocky Mountains, brown creepers are found more in older red cedars, spruce-fir, and mixed conifer rather than in younger forests.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: forest
Brown creepers (Certhia americana) are the only treecreepers in North America. They are found throughout North America from Canada and Alaska to as far south as northern Nicaragua. In Alaska and Canada, brown creepers generally breed along the coast. In British Columbia, brown creepers breed along the western coast and through the central and southern interior. Limited surveys have been done to determine the northern limits of brown creepers. In the western United States, brown creepers are found throughout forested areas of the Rocky Mountains in western Washington, Oregon and the northern mountains of California.
Brown creepers are year-round residents throughout much of their range. However, brown creepers that breed in the northern part of the geographic range migrate south for the winter. Brown creepers winter throughout most of the United States except for high mountain regions, the Great Basin, Sonoran Desert, southern Texas and Florida.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Brown creepers interact with other birds such as red-headed woodpeckers (Melanerpes erythrocephalus). Interactions can become hostile during territory establishment. Brown creepers compete for territories as well as food. They are also occasional hosts for parasitic brown-headed cowbirds (Molothrus ater).
As insectivores, brown creepers may help to control pest populations.
Positive Impacts: controls pest population
There are no known adverse affects of brown creepers on humans.
Brown creepers are listed as a species of least concern by the IUCN. They are not protected under CITES or the U.S. Endangered Species act. However, they are endangered in Kentucky, threatened in Illinois, of special concern in Indiana, New Jersey, and Ohio, and protected in Idaho, Montana, and New York. Brown creepers are also protected under the US Migratory Bird Treaty Act.
The global population of brown creepers in estimated at 5,400,000 individuals. Population trends and causes of mortality of brown creepers are not well studied.
US Migratory Bird Act: protected
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
Brown creepers communicate primarily using vocalizations. When fighting for a territory, males sing a high pitched song. Vocalizations by males can be heard during the breeding season. The sounds are high and thin and vary within populations.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Brown creepers are monogamous. Males sing to attract a mate. The pair then chases one another, rapidly fluttering their wings and exposing their white undersides. Courtship feeding (where the male feeds the female) occurs throughout the nesting cycle until the eggs have hatched. Breeding pairs remain together up to several weeks after their chicks are ready to fly.
Mating System: monogamous
Brown creepers generally begin breeding in April, with breeding season peaking in May, June and July. Incubation in Michigan has been recorded as early as May 20.
The male and female chose the nest site together, but the female builds the nest. Nests are almost always built between the trunk and a loose piece of bark on a dead or dying tree. However, nests are occasionally found in locations such as inside a stack of concrete blocks and under loosened roof shingles. Nests take 6 to 30 days to build and are lined with feathers and bark.
The female lays 3 to 7 eggs and begins incubation after the last egg is laid. Incubation lasts 13 to 17 days. The female does all of the incubation and the male brings food to her.
The altricial chicks all hatch on the same day. The female broods them during bad weather, and both parents feed them. They fledge after 15 to 17 days, but continue to be fed by the parents for at least two weeks.
Data on the exact age of first breeding and intervals between breeding are scarce, although it is believed that breeding occurs in the first year.
Breeding interval: Brown creepers breed once per year and raise one brood per breeding season.
Breeding season: Breeding occurs from April through July
Range eggs per season: 3 to 7.
Range time to hatching: 13 to 17 days.
Range fledging age: 15 to 17 days.
Range time to independence: 14 (low) days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Both parents search for a nest site, but the female builds the nest. The female does all of the incubation and brooding, during which the male feeds her. Both parents feed the chicks during the nestling and fledgling stages, before they become independent. Both adults also carry eggshells and fecal sacs away from the nest.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
A small (5 inches), strangely-shaped tree-dwelling bird, the Brown Creeper is most easily identified by its mottled brown back, short legs, and long, curved bill. Other field marks include a brown tail, white breast, and white eye-stripes. Male and female Brown Creepers are similar to one another in all seasons. The Brown Creeper breeds in the northeastern U.S. and southern Canada, along the west coast from Alaska to California, and at higher elevations in the Rocky Mountains. This species also breeds in the mountains of central Mexico and locally south to Nicaragua. In winter, this species withdraws from more northern portions of its breeding range, and may be found more widely across the southern U.S. and on the Great Plains. Brown Creepers breed primarily in old-growth evergreen forests, but may also breed in deciduous forests at the southern limits of their range. In winter, this species may be found more frequently in deciduous forests and forests with younger trees. Brown creepers primarily eat bark-dwelling insects, with small amounts of seeds eaten during the winter when insects are scarce. The feeding behavior of the Brown Creeper is unique among birds in North America. Brown Creepers are most frequently observed “creeping” up the sides of large trees, probing the deeply-furrowed bark with their bills to extract insect prey. After reaching the top of the main trunk, Brown Creepers will fly to the base of another nearby tree and start again. With the aid of binoculars, it may also be possible to identify Brown Creeper nests wedged behind peeling pieces of bark. This species is primarily active during the day.
A small (5 inches), strangely-shaped tree-dwelling bird, the Brown Creeper is most easily identified by its mottled brown back, short legs, and long, curved bill. Other field marks include a brown tail, white breast, and white eye-stripes. Male and female Brown Creepers are similar to one another in all seasons. The Brown Creeper breeds in the northeastern U.S. and southern Canada, along the west coast from Alaska to California, and at higher elevations in the Rocky Mountains. This species also breeds in the mountains of central Mexico and locally south to Nicaragua. In winter, this species withdraws from more northern portions of its breeding range, and may be found more widely across the southern U.S. and on the Great Plains. Brown Creepers breed primarily in old-growth evergreen forests, but may also breed in deciduous forests at the southern limits of their range. In winter, this species may be found more frequently in deciduous forests and forests with younger trees. Brown creepers primarily eat bark-dwelling insects, with small amounts of seeds eaten during the winter when insects are scarce. The feeding behavior of the Brown Creeper is unique among birds in North America. Brown Creepers are most frequently observed “creeping” up the sides of large trees, probing the deeply-furrowed bark with their bills to extract insect prey. After reaching the top of the main trunk, Brown Creepers will fly to the base of another nearby tree and start again. With the aid of binoculars, it may also be possible to identify Brown Creeper nests wedged behind peeling pieces of bark. This species is primarily active during the day.
The brown creeper (Certhia americana), also known as the American treecreeper, is a small songbird, the only North American member of the treecreeper family Certhiidae.
Adults are brown on the upper parts with light spotting, resembling a piece of tree bark, with white underparts. They have a long thin bill with a slight downward curve and a long stiff tail used for support as the bird creeps upwards. The male creeper has a slightly larger bill than the female. Brown creepers are smaller than white-breasted nuthatches but larger than golden-crowned kinglets.[2]
Measurements:[3]
Its voice includes single very high pitched, short, often insistent, piercing calls; see, or swee. The song often has a cadence like; pee pee willow wee or see tidle swee, with notes similar to the calls. Creepers in California have songs of four to nine syllables, except in the San Bernardino Mountains, where there are as many as nine to thirteen syllables per song, but within the same two second time frame.[4]
This species's avoidance of edges, cryptic plumage, and high-pitched vocalizations contribute to a low survey detection rate compared to other species.[5]
Their breeding habitat is mature forests, especially conifers, in Canada, Alaska and the northeastern and western United States. They are permanent residents through much of their range; many northern birds migrate farther south to the United States. Brown creeper has occurred as a vagrant to Bermuda and Central America's mountains in Guatemala, Honduras and the northern cordillera of El Salvador. Since 1966 the brown creeper has experienced a yearly 1.5% population increase throughout the northeastern and northwestern (Pacific coast) regions of its range.[6] The first breeding brown creepers in the Northwest Territories were detected inn 2008, in the Liard Valley, which may be a result of northern range expansion.[5]
As a migratory species with a northern range, this species is a conceivable vagrant to western Europe. However, it is intermediate in its characteristics between common treecreeper and short-toed treecreeper, and has sometimes in the past been considered a subspecies of the former, although its closest relative seems to be the latter (Tietze et al., 2006). Since the two European treecreepers are themselves among the most difficult species on that continent to distinguish from each other, a brown creeper would probably not even be suspected, other than on a treeless western island, and would be difficult to verify even then.
Brown creepers prefer mature, moist, coniferous forests or mixed coniferous/deciduous forests. They are found in drier forests as well, including Engelman Spruce and larch forest in eastern Washington. They generally avoid the rainforest of the outer coast. While they generally nest in hardwoods, conifers are preferred for foraging.
Breeding brown creepers generally require trees of a large diameter, whose deeper bark furrows support large amounts of bark-dwelling invertebrates such as spiders to make up a foraging substratum. They also require continual renewal of snags, with a preference for Balsam Fir in their New Brunswick breeding range.[7]
Brown creepers have been recorded breeding in the dry season (January–February) in Chalatenango Department, El Salvador, a behaviour unusual to insectivorous birds and shared in the region only by the golden-fronted woodpecker.[8]
Thirteen subspecies are recognised:[9]
As with many of Washington's birds, the Cascades divide this species into two subspecies. The species has declined in much of North America but appears to be doing well in Washington, with a small (not significant) increase on the state's breeding bird survey since 1966.
In Wyoming, brown creepers have been recognized as preferring habitat within large, intact and mature stands of spruces, firs, or lodgepole pine. It is therefore potentially vulnerable to logging, climate change, or replacement of those tree species by Ponderosa pine.[10] However, it is not considered a species of serious concern in that state.[11]
In New Brunswick, brown creepers have been shown to respond negatively to even moderate forestry. Conservation efforts in the province have focused on maintaining unmanaged patches with high densities of trees and snags in mature forest.[7]
Ivory-billed woodcreepers (Xiphorhynchus flavigaster) have been observed extracting brown creeper nestlings and dropping them away from the nest.[8]
Brown creepers forage on tree trunks and branches, typically spiraling upwards from the bottom of a tree trunk, and then flying down to the bottom of another tree. They creep slowly with their body flattened against the bark, probing with their beak for insects. They will rarely feed on the ground. They mainly eat small arthropods found in the bark, but sometimes they will eat seeds in winter.
Breeding season typically begins in April. The female will make a partial cup nest either under a piece of bark partially detached from the tree, or in a tree cavity. It will lay 3–7 eggs, and incubation lasts approximately two weeks. Both of the parents help feed the chicks. Parents both take turns feeding nestlings and removing fecal sacs from the nest.[8]
A creeper at Great Falls, MD, USA
Brown creeper spiraling in Biddeford, ME
.jpg)
In Coastal Southern Alaska
.jpg)
In Ontario, Canada
The brown creeper (Certhia americana), also known as the American treecreeper, is a small songbird, the only North American member of the treecreeper family Certhiidae.
