Animal Diversity Web

Di­ver­sity

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). (Dra­goo and Hon­ey­cutt, 1997; Flynn, et al., 2005; Nowak, 1991; Sato, et al., 2004; Vaughan, et al., 2000; Whitaker and Hamil­ton, 1998)

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. (Nowak, 1991; Vaughan, et al., 2000; Whitaker and Hamil­ton, 1998)

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. (Kruska, 1990; Nowak, 1991)

Ge­o­graphic Range

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. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

• Biogeographic Regions
• nearctic
  • native
• oriental
• neotropical
  • native

Habi­tat

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. (Kruska, 1990; Nowak, 1991)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• forest
• scrub forest
• mountains

• Other Habitat Features
• suburban
• agricultural

Phys­i­cal De­scrip­tion

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. (Kruska, 1990; Nowak, 1991; Vaughan, et al., 2000; Whitaker and Hamil­ton, 1998)

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). (Kruska, 1990; Nowak, 1991)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

Re­pro­duc­tion

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. (Nowak, 1991; Whitaker and Hamil­ton, 1998)

• 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. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

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. (Kruska, 1990; Thom, et al., 2004)

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. (Kruska, 1990)

• 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. (Kruska, 1990; Nowak, 1991)

• 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

Lifes­pan/Longevity

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. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

Be­hav­ior

Mem­bers of the fam­ily Mephi­ti­dae are per­haps most fa­mil­iar to peo­ple be­cause of their con­spic­u­ous an­tipreda­tor be­hav­ior. All mephi­tids can pro­ject a sticky, foul-smelling se­cre­tion from their anal scent glands in order to deter a po­ten­tial threat. Stink bad­gers can spray over one meter, whereas some skunks (e.g. Mephi­tis mephi­tis) can spray an at­tacker at dis­tances over 6 me­ters. When con­fronted with a pre­sumed threat, skunks first face the threat, raise their tails with hair stand­ing on end, and might also stomp on the ground. Skunks may even stand on their forepaws in a "hand­stand" as they face their at­tacker. If suf­fi­ciently pro­voked, they will bend their bod­ies in a U-shape, aim­ing their hindquar­ters at the threat and spray­ing fluid. Typ­i­cally, skunks aim for a preda­tor's eyes, which are es­pe­cially sen­si­tive to the fluid. In ad­di­tion to spray­ing at­tack­ers, some skunks (e.g., Spi­lo­gale puto­rius) climb trees to avoid dan­ger. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

Skunks and stink bad­gers are noc­tur­nal. They spend the day­time hours in bur­rows or hol­low logs, and for­age in the evenings for veg­e­ta­tion, in­sects, worms, and small ver­te­brates. In sea­sonal cli­mates, skunks re­main in their dens dur­ing the win­ter months. While they do not enter deep hi­ber­na­tion, they do sub­sist mainly on fat re­serves. Com­mu­nal dens help skunks con­serve en­ergy in the win­ter. (Kruska, 1990; Nowak, 1991)

Skunks are not typ­i­cally ag­gres­sive to­wards each other, or to het­erospecifics. Home ranges typ­i­cally over­lap, and males of some species only ac­tively de­fend fe­males dur­ing the mat­ing sea­son. Al­though skunks gen­er­ally for­age alone, they may den in groups of sev­eral in­di­vid­u­als, or even with other species. In many cases, adult males den by them­selves or only with fe­males. (Kruska, 1990; Nowak, 1991)

• Key Behaviors
• terricolous
• fossorial
• nocturnal
• motile
• hibernation

Com­mu­ni­ca­tion and Per­cep­tion

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. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

• Communication Channels
• visual
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

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. (Kruska, 1990; Nowak, 1991)

• Primary Diet
• omnivore

Pre­da­tion

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. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

• Anti-predator Adaptations
• aposematic

• Known Predators

  • Canis latrans
  • Lynx canadensis
  • Taxidea taxus
  • Puma concolor
  • foxes
  • civets
  • eagles
  • owls
  • great horned owls (Bubo virginianus)

Ecosys­tem Roles

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. (Nowak, 1991; Whitaker and Hamil­ton, 1998)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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. (Nowak, 1991; Whitaker and Hamil­ton, 1998)

• Positive Impacts
• food
• body parts are source of valuable material
• source of medicine or drug
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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. (Kruska, 1990; Nowak, 1991; Whitaker and Hamil­ton, 1998)

• Negative Impacts
• injures humans
  • causes disease in humans
• causes or carries domestic animal disease

Con­ser­va­tion Sta­tus

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. (IUCN 2004, 2004; Kruska, 1990; Whitaker and Hamil­ton, 1998)

• IUCN Red List [Link]

  Not Evaluated

Other Com­ments

The com­mon name "skunk" has its ori­gins in Al­go­nquin di­alects. (Kruska, 1990)

Con­trib­u­tors

Tanya Dewey (ed­i­tor), An­i­mal Di­ver­sity Web.

Matthew Wund (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Am­stislavsky, S., Y. Ter­novskaya. 2000. Re­pro­duc­tion in Mustelids. An­i­mal Re­pro­duc­tion Sci­ence, 60-61: 571-581.

Dra­goo, J., R. Hon­ey­cutt. 1997. Sys­tem­at­ics of mustelid-like car­ni­vores. Jour­nal of Mam­mal­ogy, 78/2: 426-443.

Flynn, J., J. Finarelli, S. Zehr, J. Hsu, M. Ned­bal. 2005. Mol­e­c­u­lar phy­logeny of the Car­nivora (Mam­malia): as­sess­ing the im­pact of in­creased sam­pling on re­solv­ing enig­matic re­la­tion­ships. Sys­tem­atic Bi­ol­ogy, 54/2: 317-337.

IUCN 2004, 2004. "2004 IUCN Redlist of Threat­ened Species" (On-line). Ac­cessed July 26, 2005 at http://​www.​iucnredlist.​org/​.

Koepfli, K., R. Wayne. 2003. Type I Sts mark­ers are more in­for­ma­tive than cy­tochrome b in phy­lo­ge­netic re­con­struc­tion of the Mustel­idae (Mam­malia: Car­nivora). Sys­tem­atic Bi­ol­ogy, 52/5: 571-593.

Kruska, D. 1990. Mustel­idae. Pp. 388-449 in B Grz­imek, ed. Grz­imek's En­cy­clo­pe­dia of Mam­mals, Vol. 3, 1 Edi­tion. New York: Mc­Graw-Hill.

Marmi, J., J. Lopez-Gi­raldez, X. Domingo-Roura. 2004. Phy­logeny, evo­lu­tion­ary his­tory and tax­on­omy of the Mustel­idae based on se­quences of the cy­tochrome b gene and a com­plex repet­i­tive flank­ing re­gion. Zo­o­log­ica Scripta, 33/6: 481-499.

Nowak, R. 1991. Car­nivora: fam­ily Mustel­idae. Pp. 1104-1143 in Walker's Mam­mals of the World, Vol. 2, 5th Edi­tion. Bal­ti­more: Johns Hop­kins Uni­ver­sity Press.

Sato, J., T. Hosada, M. Wol­san, H. Suzuki. 2004. Mol­e­c­u­lar phy­logeny of arc­toids (Mam­malia: Car­nivora) with em­pha­sis on phy­lo­ge­netic and tax­o­nomic po­si­tions of the fer­ret-bad­gers and skunks. Zo­olo­gial Sci­ence, 21: 111-118.

Thom, M., D. John­son, D. Mac­don­ald. 2004. The Evo­lu­tion andThe evo­lu­tion and main­te­nance of de­layed im­plan­ta­tion in the Mustel­idae (Mam­malia: Car­nivora). Evo­lu­tion, 58/1: 175-183.

Vaughan, T., J. Ryan, N. Czaplewski. 2000. Mam­mal­ogy, 4th Edi­tion. Toronto: Brooks Cole.

Whitaker, J., W. Hamil­ton. 1998. Mam­mals of the East­ern United States. Ithaca: Com­stock Pub­lish­ing.