Marmota monaxwoodchuck

Ge­o­graphic Range

Mar­mota monax is the most wide­spread North Amer­i­can mar­mot species. The south­ern lim­its of its range ex­tend from east­ern Ok­la­homa, north­ern Louisiana, Al­abama, and Geor­gia to North Car­olina. The east­ern lim­its of its range ex­tend from North Car­olina, along the At­lantic coast, to Labrador, Canada. It's north­ern lim­its range from Labrador to south­ern Alaska. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kays and Wil­son, 2002; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

Habi­tat

Mar­mota monax has a wide ge­o­graphic range and in­hab­its many dif­fer­ent ecosys­tems. It is typ­i­cally found in low el­e­va­tion forests, small wood­lots, fields, pas­tures, and hedgerows. Human ac­tiv­i­ties (e.g., clear­ing forests, build­ing roads, and agri­cul­ture) have in­creased food ac­cess and abun­dance al­low­ing M. monax to thrive. It con­structs dens in well drained soils, and most have sum­mer (lo­cated near food sources) and win­ter (lo­cated near pro­tec­tive cover) dens. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Range elevation
    low elevation (low) m
    (low) ft

Phys­i­cal De­scrip­tion

Wood­chucks are stocky in ap­pear­ance and often stand up on their hind legs, mak­ing them look tall. Their pelage varies greatly in color but ranges from gray to cin­na­mon to dark brown. Their body is cov­ered with white-tipped guard hairs giv­ing them a griz­zled ap­pear­ance. Their paws vary in color from a typ­i­cal black to dark brown in most sub­species. How­ever, one sub­species has paws that ap­pear pink. Their short bushy tail is often black to dark brown and is 20 to 25% their total body length. They weigh from 2 to 6 kg, range from 415 to 675 mm in total length, and have tails that range from 100 to 160 mm in length. Al­though males and fe­males are the same color, males are larger than fe­males. Wood­chucks have white teeth, which is un­char­ac­ter­is­tic of ro­dents, and a den­tal for­mula of 1/1, 0/0, 2/1, 3/3, for a total of 22 teeth. They have rounded ears that can cover the ex­ter­nal au­di­tory canal which pre­vents dirt from en­ter­ing the ear canal while bur­row­ing. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kays and Wil­son, 2002; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Sexual Dimorphism
  • male larger
  • Range mass
    2 to 6 kg
    4.41 to 13.22 lb
  • Range length
    415 to 675 mm
    16.34 to 26.57 in
  • Average basal metabolic rate
    3.696 W
    AnAge

Re­pro­duc­tion

Wood­chucks are polyg­y­nous, with males hav­ing mul­ti­ple mates per sea­son. Male wood­chucks emerge from hi­ber­na­tion ear­lier than fe­males in order to es­tab­lish ter­ri­to­ries, dom­i­nance hi­er­ar­chies, and to search for mates. Older, more dom­i­nant males hold ter­ri­to­ries whereas younger males are no­madic. With the ex­cep­tion of mat­ing sea­son, wood­chucks are non-so­cial, and dur­ing breed­ing sea­son, male-fe­male in­ter­ac­tions are lim­ited to cop­u­la­tion. Fe­males are mo­noe­strous and mat­ing oc­curs only dur­ing the spring. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

Breed­ing oc­curs shortly after emer­gence from hi­ber­na­tion in the spring, al­though the exact time varies by lat­i­tude. Fe­male wood­chucks give birth to 1 to 9 off­spring, with most lit­ters rang­ing be­tween 3 and 5 pups. Pups weigh be­tween 26 and 27 grams upon birth. Ges­ta­tion lasts from 31 to 32 days and wean­ing oc­curs around 44 days old. Pups be­come in­de­pen­dent very quickly and leave the mother around age 2 months old. Some wood­chucks be­come sex­u­ally ma­ture at 1 year old, how­ever, they often have a lower preg­nancy rate than oth­ers. Typ­i­cally, wood­chucks be­come sex­u­ally ma­ture by age 2. Breed­ing in cap­tive in­di­vid­u­als can occur year round. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998)

  • Breeding interval
    Woodchucks breed once yearly
  • Breeding season
    Mating occurs between February and May depending on latitude
  • Range number of offspring
    1 to 9
  • Average number of offspring
    4.5
    AnAge
  • Range gestation period
    31 to 32 days
  • Average weaning age
    44 days
  • Average time to independence
    2 months
  • Range age at sexual or reproductive maturity (female)
    1 to 2 years
  • Range age at sexual or reproductive maturity (male)
    1 to 2 years

Fol­low­ing birth, fe­males pro­vide all of the care for wood­chuck pups. Pups nurse for ap­prox­i­mately 44 days and be­come in­de­pen­dent at around 2 months of age. Oc­ca­sion­ally, fe­males in­herit their moth­ers den. Pups use the den for pro­tec­tion while the mother is away. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Parental Investment
  • altricial
  • female parental care
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female
  • inherits maternal/paternal territory

Lifes­pan/Longevity

Wood­chucks live 4 to 6 years in the wild but, due to pre­da­tion and dis­ease, often do not live past age 3. Wood­chucks may live up to 10 years in cap­tiv­ity. (Forsyth, 1985; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Range lifespan
    Status: wild
    2 to 6 years
  • Range lifespan
    Status: captivity
    10 (high) years
  • Typical lifespan
    Status: wild
    4 to 6 years
  • Average lifespan
    Status: captivity
    14 years
    AnAge

Be­hav­ior

Wood­chucks are di­ur­nal, soli­tary an­i­mals. Dom­i­nant males have home ranges of ap­prox­i­mately 10,000 m^2, which usu­ally over­laps with those of at least 2 other fe­males. Sub­or­di­nate males are no­madic. Fe­males have a home range of about 2,500 m^2 in the spring, which ex­pands to greater than 10,000 m^2 after giv­ing birth. Wood­chucks are bur­row­ing mam­mals and gen­er­ally con­struct sum­mer and win­ter dens. These dens gen­er­ally have sev­eral en­trances (in­clud­ing an es­cape hole) and many cham­bers and tun­nels. Wood­chucks usu­ally feed twice daily dur­ing the sum­mer, with each feed­ing ses­sion last­ing no more than 2 hours. They are often found sun­ning them­selves in the mid­dle of the day dur­ing sum­mer. Al­though usu­ally aso­cial, wood­chucks will some­times greet each other nose to nose. Wood­chucks threat­ened by con­specifics re­spond by arch­ing their bod­ies, bar­ing their teeth, and rais­ing their tail. They also com­mu­ni­cate via scent glands and vo­cal­iza­tions. Gen­er­ally, wood­chucks are true hi­ber­na­tors; how­ever, in the south­ern part of their range, they have been known to stay ac­tive through­out the year. Wood­chucks mate soon after emerg­ing from hi­ber­na­tion. Dur­ing cer­tain parts of the year, they may enter tor­por dur­ing the day. ("The Roots of Mar­mot So­cial­ity", 2001; "Wood­chuck", 2007; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998; Yah­ner, 2001)

  • Range territory size
    2,500 to >10,000 m^2

Home Range

Wood­chuck home ranges vary through­out their ge­o­graphic range. How­ever, ev­i­dence sug­gests that home ranges are ap­prox­i­mately 10,000 m^2 for males and 2,500 m^2 for fe­males, prior to par­tu­ri­tion. (Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

Com­mu­ni­ca­tion and Per­cep­tion

Wood­chucks are ter­ri­to­r­ial and non-so­cial. Sight, smell, and sound are im­por­tant for com­mu­ni­ca­tion among con­specifics. Se­cre­tions from fa­cial and anal glands are used to de­mar­cate ter­ri­to­r­ial bound­aries. They also hiss, growl, shriek, whis­tle, teeth-chat­ter, and bark. Wood­chucks use their sight to de­tect preda­tors and to make vi­sual threats to other con­specifics. Vocal threats, vi­sual threats, and fight­ing are used to es­tab­lish so­cial rank. (Forsyth, 1985; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

Food Habits

Wood­chucks are di­ur­nal and their feed­ing ac­tiv­ity is high­est dur­ing morn­ing and af­ter­noon. For­ag­ing bouts last less than 2 hours. Pre­ferred for­age in­cludes al­falfa (Med­icago sativa), clover (Genus: Tri­folium), and dan­de­lion (Tarax­acum of­fic­i­nale). Other foods in­clude bark, leaves, in­sects, and bird eggs. All wood­chucks store fat for win­ter hi­ber­na­tion. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Animal Foods
  • eggs
  • insects
  • mollusks
  • Plant Foods
  • leaves
  • wood, bark, or stems
  • seeds, grains, and nuts
  • flowers

Pre­da­tion

Wood­chucks avoid preda­tors by climb­ing trees and look­ing up pe­ri­od­i­cally while feed­ing. Their large body size may de­ters some preda­tors. They often use their teeth to de­fend them­selves and pro­duce a shrill whis­tle when threat­ened. Whis­tles also serve as a warn­ing call to con­specifics, es­pe­cially ju­ve­niles. Young wood­chucks hide in and around the den for pro­tec­tion from po­ten­tial preda­tors. Known preda­tors in­clude gray wolves (Canis lupus), coy­otes (Canis la­trans), do­mes­tic dogs (Canis fa­mil­iaris), red foxes (Vulpes vulpes), gray foxes (Uro­cyon cinereoar­gen­teus), black bears (Ursus amer­i­canus), lynx (Lynx canaden­sis), bob­cats (Lynx rufus), hawks (Ac­cip­itri­dae), and snakes (Ser­pentes). (Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

Ecosys­tem Roles

Aban­doned wood­chuck dens are used by a num­ber of dif­fer­ent species, in­clud­ing rab­bits, skunks, rac­coons, opos­sums, foxes, weasels, ground squir­rels, river ot­ters, chip­munks, meadow voles, short-tailed shrews, house mice, pine voles, white-footed mice, lizards, snakes, and arthro­pods. They are also host to a num­ber of dif­fer­ent par­a­site species, in­clud­ing bot­flies, ne­ma­todes, pro­to­zoa, tu­laremia, ra­bies, chig­gers, mites, ticks, fleas, and lice. Wood­chucks are also prey for many preda­tors species. (Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

Com­men­sal/Par­a­sitic Species

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Wood­chucks have been used in bio­med­ical re­search in­ves­ti­gat­ing he­pati­tis B, meta­bolic func­tion, obe­sity, en­ergy bal­ance, the en­docrine sys­tem, re­pro­duc­tion, neu­rol­ogy, car­dio­vas­cu­lar dis­ease, cere­brovas­cu­lar dis­ease, and neo­plas­tic dis­ease. Ad­di­tion­ally, they are often tar­geted as game by hunters. (Grz­imek, 2003; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Positive Impacts
  • research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Mar­mota monax is known to de­stroy gar­dens, pas­tures, and agri­cul­tural crops. Their bur­rows have been known to in­jure live­stock and dam­age farm equip­ment and build­ing foun­da­tions. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998)

  • Negative Impacts
  • crop pest

Con­ser­va­tion Sta­tus

Due to their abun­dance and broad ge­o­graphic range, wood­chucks are listed as a species of least con­cern on the IUCN Red List of Threat­ened Species.

Other Com­ments

Wood­chucks have nu­mer­ous com­mon names, in­clud­ing ground hog, and whis­tle pig. The word "wood­chuck" is a mis­in­ter­pre­ta­tion of their Na­tive Amer­i­can name "wuchak", which roughly trans­lates as "the dig­ger". Ground­hog Day oc­curs when Punx­sutawney Phil, a cap­tive wood­chuck held in rural Penn­syl­va­nia, is awak­ened from hi­ber­na­tion in order to de­ter­mine if he will see his shadow. Ac­cord­ing to the leg­end, if he sees his shadow there will be 6 ad­di­tional weeks of win­ter. If he does not see his shadow, leg­end pre­dicts an early spring. The leg­end of Ground­hog Day is likely due to the fact that wood­chucks often re-en­ter hi­ber­na­tion after emerg­ing from their dens pre­ma­turely. ("Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Yah­ner, 2001; "Wood­chuck", 2007; Forsyth, 1985; Grz­imek, 2003; Kurta, 1995; Kwiencin­ski, 1998; Whitaker, Jr. and Hamil­ton, Jr., 1998; Yah­ner, 2001)

Con­trib­u­tors

Clin­ton To­bias (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor, in­struc­tor), Uni­ver­sity of Michi­gan-Ann Arbor, John Berini (ed­i­tor), An­i­mal Di­ver­sity Web Staff, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

herbivore

An animal that eats mainly plants or parts of plants.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

induced ovulation

ovulation is stimulated by the act of copulation (does not occur spontaneously)

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

polygynous

having more than one female as a mate at one time

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

soil aeration

digs and breaks up soil so air and water can get in

solitary

lives alone

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

Ref­er­ences

An­drom­eda Ox­ford, Ltd. 2001. The Roots of Mar­mot So­cial­ity. Pp. 612-613 in D Mac­don­ald, ed. The En­cy­lo­pe­dia of Mam­mals, Vol. 3, 2 Edi­tion. New York, NY: Facts On File, Inc..

En­cy­clopae­dia Bri­tan­nica, Inc. 2007. Wood­chuck. Pp. 741 in The New En­cy­clopae­dia Bri­tan­nica, Vol. 12, 15 Edi­tion. Chicago, IL: En­cy­clopae­dia Bri­tan­nica, Inc..

Forsyth, A. 1985. Mam­mals of the Cana­dian Wild. Cam­den East, On­tario: Cam­den House.

Grz­imek, B. 2003. Wood­chuck. Pp. 152-153 in M Mc­Dade, ed. Grz­imek's An­i­mal Life En­cy­clo­pe­dia, Vol. 16/5, 2 Edi­tion. Farm­ing­ton Hills, MI: Gale Group.

Kays, R., D. Wil­son. 2002. The Mam­mals of North Amer­ica. Prince­ton, NJ: Prince­ton Uni­ver­sity Press.

Kurta, A. 1995. Mam­mals of the Great Lakes Re­gion. Ann Arbor, MI: Uni­ver­sity of Michi­gan Press.

Kwiencin­ski, G. 1998. Mar­mota monax. Mam­malian Species, 591: 1-8.

Whitaker, Jr., J., W. Hamil­ton, Jr.. 1998. Mam­mals of the East­ern United States. Ithaca, NY: Cor­nell Uni­ver­sity Press.

Yah­ner, R. 2001. Fas­ci­nat­ing Mam­mals: con­ser­va­tion and ecol­ogy in the mid-east­ern states. Pitts­burgh, Pa: Uni­ver­sity of Pitts­burgh Press.