The common name "skunk" has its origins in Algonquin dialects.
Although their scent gland secretions are a potent deterrent to predators, mephitids are at risk of predation. This is especially true for young skunks. When they are out of their burrows, skunks remain relatively conspicuous and depend on their warning coloration to deter attackers. Known predators of skunks and stink badgers are larger carnivores such as coyotes, foxes, pumas, civets, American badgers, and lynx. Birds of prey, having less well-developed olfaction than mammals, are less susceptible to the skunks' odor, although being sprayed in the eyes is a risk. Avian predators may include eagles and owls. Great horned owls (Bubo virginianus) are known to prey on skunks.
Known Predators:
Anti-predator Adaptations: aposematic
Skunks and stink badgers can be recognized by their striking color patters. They are generally black (or sometimes brown) with a prominent, contrasting pattern of white fur on their faces, backs, and/or their tails. Generally, they have either white spots, or a white stripe running from their head, down their back to their tail. Patterns vary within and among species. For example, spotted skunks, as the name implies, have many white spots on a black background. Striped skunks have white dorsal stripes of varying thickness and length that may or may not run through the tail or extend onto the head. Coloration in skunks and stink badgers serves as an aposematic signal to would-be predators. All mephitids have extremely well-developed anal scent glands with which they produce noxious odors to deter threats. The product of the scent glands is secreted through nipples near the anus, and can be projected between 1 and 6 meters towards a threatening animal.
Mephitids have a relatively long rostrum (although it is not so large in Spilogale), broad, squat bodies, and often a thickly-furred tail. They have short limbs and robust claws that are well-suited for digging. Spotted skunks (Spilogale) are the smallest members of this family, weighing between 200 g and 1 kg. Hog-nosed skunks (Conepatus) reach the largest sizes (up to 4.5 kg).
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
First-year skunks suffer high mortality (~ 50% - 70%) as a result of predation and disease. Those that survive can live up to 7 years in the wild, although 5 to 6 years is more typical, and up to 10 years in captivity. Humans are a significant threat to skunks, either killing them deliberately to control the spread of rabies, or killing them accidentally while skunks make their way onto roads and highways.
Members of the family Mephitidae can be found in a variety of habitats, including relatively open forests, grasslands, agricultural areas, meadows, open fields, and rocky montane areas. Stink badgers may even spend some of their time in caves. Mephitids generally do not occur in very dense forests or in wetlands. During the day, skunks and stink badgers seek shelter in burrows or under the cover of rocks or logs. They can dig the burrows themselves, or may use the dens of other species, such as marmots or badgers. At night, skunks and stink badgers come out from their dens and forage. Some skunks are agile climbers (e.g., Spilogale) and can be found in trees in search of food or to avoid predators.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest ; mountains
Other Habitat Features: suburban ; agricultural
Three genera of Mephitidae occur solely in the New World. Mephitis ranges from southern Canada to Costa Rica, Conepatus ranges from the Southern United States to Argentina, and Spilogale ranges from Southern British Coumbia in the west, and Pennsylvania in the east, south to Costa Rica. Mydaus is restricted to Indonesia and the Philippines in Southeast Asia.
Biogeographic Regions: nearctic (Native ); oriental ; neotropical (Native )
Members of the family Mephitidae are omnivorous, but a large proportion of their diet consists of animal material. Skunks and stink badgers eat a variety of invertebrates such as worms and insects. They also eat small vertebrates such as rodents, lizards, snakes, birds and eggs. Mephitids forage nocturnally, rooting for and digging up prey as they wander through their home range. In northern areas, skunks greatly increase their fat reserves during the fall. During the winter months these skunks spend most of their time sleeping in dens, but will emerge to forage on warmer days.
Primary Diet: omnivore
As omnivores, mephitids potentially impact a variety of plant and animal populations in their respective communities. In particular, many species consume large quantities of insects and rodents. Although skunks have many potential predators, they are not the staple in the diet of any other species. Following one encounter with a skunk, predators often learn not to pursue them. Skunks also harbor and transmit several parasites and diseases such as distemper and histoplasmosis. Rabies is a significant problem for skunks. In the midwestern United States, striped skunks have recently overtaken domestic dogs as the species most commonly afflicted with rabies.
Commensal/Parasitic Species:
Skunks and stink badgers are generally beneficial to humans because they eat a variety of insect and rodent pests. The pelts of skunks are sometimes traded, although they are currently not in high demand. The fur of Spilogale is considered to be the finest among skunks, although no skunk pelts are considered highly valuable. Occasionally, people eat stink badgers (after removing the stink glands) or use a mixture of their skin and water in an attempt to cure rheumatism or fevers.
Positive Impacts: food ; body parts are source of valuable material; source of medicine or drug ; controls pest population
By far, humans are skunks' largest threat. Humans often consider skunks to be pests due to their smell and their occasional predation on domestic poultry and eggs. As significant vectors of rabies, skunks are often poisoned, shot, or otherwise killed in an effort to control the spread of this disease.
Negative Impacts: injures humans (causes disease in humans ); causes or carries domestic animal disease
The family Mephitidae, which includes the skunks and stink badgers, is comprised of four extant genera (Mephitis, Conepatus, Spilogale and Mydaus) and 13 species. While many authors have traditionally considered skunks a subfamily (Mephitinae) within Mustelidae, recent molecular evidence indicates that skunks do not lie within the mustelid group and should be recognized as a single family, Mephitidae, a systematic understanding that is accepted here. Stink badgers (Mydaus) have only recently been considered part of the skunk clade (Dragoo and Honeycutt, 1997; Flynn et al., 2005).
Three of the four genera of skunks inhabit the New World, collectively ranging from Canada to central South America; the exception are stink badgers (Mydaus), which occur on islands in Indonesia and the Philippines. Skunks are distinguishable by their conspicuous patterns of black and white stripes or spots, which serve as aposematic signals to would-be predators. Skunks have extremely well-developed anal scent glands with which they produce noxious odors to deter threats. Spotted skunks (Spilogale) are the smallest members of this family, weighing between 200 g and 1 kg. Hog-nosed skunks (Conepatus) reach the largest sizes (up to 4.5 kg). Mephitids have relatively long rostra (although not so pronounced in Spilogale), broad, squat bodies, and often a thickly-furred tail. They have short limbs and robust claws that are well-suited for digging.
Mephitids are mainly omnivorous. They often eat vegetation, insects and other small invertebrates, and smaller vertebrates such as snakes, birds and rodents. Mephitids are nocturnal, and inhabit a range of habitats that includes woodlands, deserts, grasslands, and rocky montane areas. They typically do not occur in dense forest. Skunks and stink badgers are adept diggers, which allows them to find food in the soil as well as to help excavate their dens. Some species can climb trees, either to seek shelter or to find food.
Skunks are generally abundant, but some populations are considered rare or possibly threatened due to demand for their fur. Big Thicket hog-nosed skunks , Conepatus mesoleucus telmalestes, known only from the Big Thicket region of Texas, are considered extinct. Conepatus chinga rex, Molina's hog-nosed skunks from northern Chile seems to have become rare as a result of hunting pressures. The Palawan stink badger is currently listed as vulnerable on the IUCN redlist, due to human induced habitat degradation and fragmentation.
Skunks are generally not vocal, but sometimes communicate with grunts, growls, and hisses. Olfaction is probably an important part of communication, especially during the mating season. Skunks are not territorial, so do not need to mark territories. Skunks have elaborate visual displays to ward off potential predators, which include holding the tail and body erect, standing on the forepaws, and stomping the ground.
Communication Channels: visual ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Generally, skunks are not territorial, and individuals of many species regularly den with conspecifics. During the mating season, males of some species may monopolize several females (e.g. Mephitis mephitis), chasing other males away when they approach. Even when males do not actively defend a group of females, male home ranges often overlap with those of females indicating that individual males may mate with several females in a season.
Mating System: polygynous
Little is known about the breeding biology of stink badgers.
Skunks are seasonal breeders; typically, the breeding season lasts two to three months, but the time of the breeding season varies among species, and within species according to geographic location.
Skunks' gestation period varies among species. In Mephitis and Conepatus, gestation lasts 2 to 3 months. Spilogale gracilis undergoes delayed implantation, in which the fertilized egg does not implant into the uterine wall for a prolonged period of time. Spilogale putorius also exhibits delayed implantation, but only in the northern part of its range. Gestation times (including delayed implantation) in these species can last 250 days or more. Delayed implantation is more typical of species and or populations that live in seasonal climates.
Skunks generally give birth to 2-10 altricial young per year in a single litter. The young are weaned after about two months and become sexually mature late in their first year of life.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous ; delayed implantation
Little is known about parental care in stink badgers. Being mammals, females must invest some care before the young are weaned.
Skunks are born in an altricial state, without fur and with their eyes closed. Although the stink glands are full at birth, young cannot use them in defense until after the first week of life, and thus rely on the mother for full protection from predators. The young are weaned after about two months and can begin foraging on their own. Young will share a den with their mothers, and perhaps other conspecifics. Den sharing is especially important during the winter in northern areas to increase survival.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); post-independence association with parents
Taxonomy and Systematics
Dragoo (2009) recognized two subfamilies within the family Mephitidae. One subfamily, Myadinae, includes the two species of Mydaus stink badgers. In the other subfamily, Mephitinae, Dragoo recognized 10 skunk species in three genera: Conepatus, Mephitis, and Spilogale. Dragoo noted that the number of species recognized will likely change as revisions are undertaken using modern methods such as molecular phylogenetic analysis. However, as of 2009, he recognized the following six genera and twelve species of mephitids:
Mydaus (2 species):Sunda Stink Badger (Mydaus javanensis), from Java, Sumatra, and Borneo (the Greater Sunda Islands), and Palawan Stink Badger (M. marchei), from the island of Palawan in the Philippines. These two species were at one time placed in two separate monotypic genera, the Palawan Stink Badger being placed in a genus Suillotaxus.
Conepatus (4 species [now 3?]): American Hog-nosed Skunk (Conepatus leuconotus), from the southwestern United States south to Nicaragua; Molina's Hog-nosed Skunk (C. chinga), from Peru to Chile, Argentina, and southeastern Brazil; Striped Hog-nosed Skunk (C. semistriatus), with an apparently disjunct distribution from southeastern Mexico to Colombia and Venezuela and northeastern and central Brazil; and Humboldt's Hog-nosed Skunk (C. humboldtii), from Chile and Argentina. Schiaffini et al. (2013) analyzed morphometric and mitochondrial DNA variation and concluded that C. chinga and C. humboldtii are actually conspecific (i.e., belong to the same species) and that environmental variation seems to be responsible for shape and size variation in Conepatus skulls from southern South America. Thus, they considered all the skunks of southern South America (Uruguay, central and southern Chile, and Argentina) to belong to a single species, C. chinga. Similar analyses previously resulted in the collapsing of the putative species C. mesoleucus ("Western Hog-nosed Skunk") into C. leuconotus ("Eastern Hog-nosed Skunk") (Dragoo et al. 2003).
Mephitis (2 species): Hooded Skunk (Mephitis macroura), found from the southwestern United States to Nicaragua, and Striped Skunk (M. mephitis), found across much of Canada and most of the United States south to northwestern Mexico.
Spilogale (4 species): Pygmy Spotted Skunk (Spilogale pygmaea), found in western Mexico; Eastern Spotted Skunk (S. putorius), found across much of the eastern and central United States; Western Spotted Skunk (S. gracilis), found in the western United States south to northern Mexico; and Southern Spotted Skunk (S. angustifrons), found from central Mexico south to Costa Rica. Although the Eastern and Western Spotted Skunks were long considered to belong to a single species, a variety of data suggests that they are at least largely reproductively isolated and should be recognized as distinct species (Kaplan and Mead 1994 and references therein; Kinlaw 1995 and references therein).Spotted skunks are the smallest of the skunks and are good climbers, able to move up and down tree trunks like squirrels.
General Ecology
Skunks are best known for their extremely enlarged scent glands (modified apocrine sweat glands) at the base of the tail, which they use to squirt a noxious fluid at potential predators. These enlarged scent glands are among the several features that were long considered to be shared with weasels, resulting in the skunks being included in the weasel family, Mustelidae. It is now clear, however, that at least some of the characters traditionally used to unite skunks and weasels are not actually shared, derived characters ("synapomorphies"), as is logically required if they are to be used as evidence that the two groups share a more recent common ancestor with each other than with other carnivorans (Dragoo and Honeycutt 1997 and references therein). Analysis of chromosomes also does not suggest a very close relationship between skunks and weasels. Molecular phylogenetic data have shed considerable light on the phylogenetic placement of the Mephitidae within the order Carnivora and consistently indicate that the skunks and mustelids are not actually closely related. As of 2013, it appears that Mephitidae is basal to a clade consisting of Ailuridae [Red Panda], Procyonidae [raccoons and allies], and Mustelidae, with Ailuridae basal to (Procyonidae + Mustelidae) (Dragoo and Honeycutt 1997 and references therein; Eizirik et al. 2010; Nyakatura and Bininda-Emonds 2012; Sato et al. 2012).
All skunks exhibit some degree of sexual dimorphism in skull morphology, but this is most evident in the spotted skunks. Male skunks have a baculum ("penis bone"), although it is smaller than it is in most carnivores, and females have an os clitoris. Dragoo (2009) reviewed the skeletal morphology of the skunks.
Skunks have been recorded from sea level to 4200 meters, but are more common at elevations below around 1800 meters. The family is distributed mainly in the New World, from Canada to Argentina, but the two species of stink badgers are found in the Philippines, Java, Borneo, and Sumatra. New World skunks are found in an extraordinary range of habitats, but generally not in the most arid and hot deserts of the southwestern United States or in arctic Canada (although there are, in fact, reports of Striped Skunks occurring north of the Arctic Circle). Northern Mexico and the southwestern United States have the highest skunk diversity, with three genera and five species, although typically no more than two species co-occur in the same habitat. Striped Skunks do well in urban areas, as do Hooded Skunks in the desert southwest of the United States. Even spotted and hog-nosed skunks may be adapting somewhat to living in urban areas. The only skunks in South America are the hog-nosed skunks, which are found in a wide range of mostly fairly open habitats. In their range in southeast Asia, stink badgers are found mainly in montane areas, although they have been found at lower elevations as well. They can occur in a range of open natural habitats, agricultural areas and secondary forest, as well as in the vicinity of human habitation.
Skunks are opportunistic and omnivorous in their feeding habits. All of them will eat insects, but insects tend to represent an especially large component of the diet for hog-nosed skunks. Hog-nosed skunks spend more time and energy digging for beetle grubs and other insect larvae than do other skunks, explaining the resemblance of their shoulder blades and humerus (upper forelimb bone) to those of American Badgers (Taxidea), which are also committed diggers. Like the nose of a hog, the nose of a hog-nosed skunk is hairless, flexible, and well suited for rooting for food.Stink badgers forage at night for worms and other invertebrates as well as eggs, carrion, and some plant matter. They are rather slow-moving animals with a top speed around that of a walking human.
Skunks dig holes in the ground or use burrows excavated by other animals. In warm weather, they will nest above ground under cover and some skunks (Hooded and spotted) will even nest in trees. They are generally nocturnal and solitary (although in very cold weather, females may den together, sometimes with a single male, to conserve body heat and body fat). Their natural predators include Coyotes, Bobcats, foxes, and owls.
Striped Skunks are known to be induced ovulators, shedding eggs within 40 to 50 hours of copulation. Dragoo (2009) reviewed the basic reproductive physiology of skunks.
A skunk's spray is a potent defense, but escape is generally a skunk's first choice when it encounters a perceived threat. If escape is not a feasible option, performing a threat display rather than actually spraying may be effective (stink badgers may play dead). If threatened, an American Hog-nosed Skunk can put on an impressive threat display, standing on its hind legs, then coming down on all fours, hissing and flinging dirt backwards and, eventually, stomping its front paws, raising its tail, baring its teeth, and spraying and biting. Depending on the circumstances, a skunk can spray either a cloud of fine mist or a narrow stream, often directed at the face, which can sting and temprarily blind a predator as well as overwhelm its olfactory system. Interestingly, a skunk isable to avoid spraying scent on its own body except for in exceptional circumstances, e.g., when it has been captured by a predator and is desperately trying to save itself or after being hit by a car.
In much of the world, domestic and feral dogs are the primary reservoirs and vectors for rabies. In the United States, however, extensive vaccination has shifted this status to wild mammals, especially carnivores. Prior to 1990, Striped Skunks accounted for the most cases of rabies reported in the United States, but after 1990 an increase in the prevalence of rabies among Northern Raccoons (Procyon lotor) bumped skunks to #2.
Conservation Status
The populations of most skunk species seem currently to be relatively secure, at least on a global scale. The Pygmy Spotted Skunk, however, is listed on the IUCN Red List as Vulnerable. It has suffered from substantial habitat destruction across much of its range and in some places these animals are killed, stuffed, and sold as souvenirs. For skunks in general, the main threats seem to be hunting by humans and habitat loss. The Palawan Stink Badger is generally common, but may be vulnerable simply because its range is rather limited. The Eastern Spotted Skunk was once common throughout the midwestern and southeastern United States, with consistent annual range-wide harvests of >>100 000 animals. In the 1940s, however, populations crashed and the decline has continued more slowly in subsequent decades, although the cause of this decline is unclear. The species is currently listed by various state agencies as endangered, threatened, or "of concern"’ across much of its range. (Gompper and Hackett 2005)
(Dragoo 2009 and references therein)
Mephitidae is a family of mammals comprising the skunks and stink badgers. They are noted for the great development of their anal scent glands, which they use to deter predators. Skunks were formerly classified as a subfamily of the Mustelidae (the weasel family); however, recent genetic evidence has caused skunks to be treated as a separate family.[1] Similarly, the stink badgers had been classified with badgers, but genetic evidence shows they share a more recent common ancestor with skunks, so they are now included in the skunk family. A 2017 study using retroposon markers indicated that they are most closely related to the Ailuridae (red pandas and allies) and Procyonidae (raccoons and allies).
There are twelve extant species of mephitids in four genera: Conepatus (hog-nosed skunks, four species); Mephitis (the hooded and striped skunks, two species); Mydaus (stink badgers, two species); and Spilogale (spotted skunks, four species). The two stink badgers in the genus Mydaus inhabit Indonesia, Brunei, Malaysia and the Philippines; the other members of the family inhabit the Americas, ranging from Canada to central South America. All other mephitids are extinct, known through fossils, including those from Eurasia.[2][3][4]
In taxonomic order, the living species of Mephitidae are:[5]
Mephitidae is a family of mammals comprising the skunks and stink badgers. They are noted for the great development of their anal scent glands, which they use to deter predators. Skunks were formerly classified as a subfamily of the Mustelidae (the weasel family); however, recent genetic evidence has caused skunks to be treated as a separate family. Similarly, the stink badgers had been classified with badgers, but genetic evidence shows they share a more recent common ancestor with skunks, so they are now included in the skunk family. A 2017 study using retroposon markers indicated that they are most closely related to the Ailuridae (red pandas and allies) and Procyonidae (raccoons and allies).
There are twelve extant species of mephitids in four genera: Conepatus (hog-nosed skunks, four species); Mephitis (the hooded and striped skunks, two species); Mydaus (stink badgers, two species); and Spilogale (spotted skunks, four species). The two stink badgers in the genus Mydaus inhabit Indonesia, Brunei, Malaysia and the Philippines; the other members of the family inhabit the Americas, ranging from Canada to central South America. All other mephitids are extinct, known through fossils, including those from Eurasia.
In taxonomic order, the living species of Mephitidae are:
