Taxidea taxus

Geographic Range

Badgers are found primarily in the Great Plains region of North America. Badgers occur north through the central western Canadian provinces, in appropriate habitat throughout the western United States, and south throughout the mountainous areas of Mexico. They have expanded their range since the turn of the 20th century and are now found as far east as Ontario, Canada.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Badgers prefer to live in dry, open grasslands, fields, and pastures. They are found from high alpine meadows to sea level (or below in Death Valley, California).

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland
• chaparral chaparral
• mountains mountains

• Wetlands
• marsh marsh

• Other Habitat Features
• agricultural agricultural

Physical Description

Badgers measure 520 to 875 mm from head to tail, with the tail making up only 100 to 155 mm of this length. Badgers weigh 4 to 12 kg. The body is flattened, and the legs are short and stocky. The fur on the back and flanks of the animal ranges from grayish to reddish. The ventrum is a buffy color. The face of the badger is distinct. The throat and chin are whitish, and the face has black patches. A white dorsal stripe extends back over the head from the nose. In northern populations, this stripe ends near the shoulders. In southern populations, however, it continues over the back to the rump. Males are significantly larger than females and animals from northern populations are larger than those from southern populations.

• Other Physical Features
• endothermic endothermic
• heterothermic heterothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

The home ranges of both male and female badgers expands during the breeding season, indicating that males and females travel more extensively to find mates. Males have larger home ranges that are likely to overlap with the home ranges of several females.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Mating occurs in late summer or early autumn but embryos are arrested early in development. Implantation is delayed until December or as late as February. After this period embryos implant into the uterine wall and resume development. So, although a female is technically pregnant for 7 months, gestation is a mere 6 weeks. Litters of 1 to 5 offspring, with an average of 3, are born in early spring. Females are able to mate when they are 4 months old, but males do not mate until the autumn of their second year. Most females mate after their first year.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous
• delayed implantation delayed implantation

Female badgers prepare a grass-lined den in which to give birth. Badgers are born blind and helpless with a thin coat of fur. The eyes of the youngsters open at 4 to 6 weeks old, and the young are nursed by their mother until they are 2 to 3 months old. Females give their young solid food before they are weaned and for a few weeks after they are weaned. Young may emerge from the den as early as 5 to 6 weeks old. Juveniles disperse at 5 to 6 months.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Badgers have lived to be 26 years old in captivity. The average lifespan in the wild has been estimated by different researchers at 4 to 5 years and at 9 to 10 years. The oldest wild badger lived to 14 years. Yearly mortality was estimated at 35% by one study. Some populations are estimated to be up to 80% yearlings or young of the year, suggesting high mortality rates.

Behavior

Badgers are solitary animals. Typical population density is about 5 animals per square kilometer. Badgers are mainly active at night, and tend to be inactive during the winter months. They are not true hibernators, but spend much of the winter in cycles of torpor that usually last about 29 hours. During torpor body temperatures fall to about 9 degrees Celsius and the heart beats at about half the normal rate. They emerge from their dens on warm days in the winter.

Badgers are excellent digging machines. Their powerfully built forelimbs allow them to tunnel rapidly through the soil, and apparently through other harder substances as well. There are anecdotal accounts of badgers emerging from holes they have excavated through blacktopped pavement and two inch thick concrete.

Their burrows are constructed mainly in the pursuit of prey, but they are also used for sleeping. A typical badger den may be as far a 3 meters below the surface, contain about 10 meters of tunnels, and have an enlarged chamber for sleeping. Badgers use multiple burrows within their home range, and they may not use the same burrow more than once a month. In the summer months they may dig a new burrow each day.

• Key Behaviors
• terricolous
• fossorial fossorial
• diurnal diurnal
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• hibernation hibernation
• solitary solitary

Home Range

Males occupy larger home ranges than females (2.4 versus 1.6 square kilometers), but this species is not known to defend an exclusive territory.

Communication and Perception

Badgers have keen vision, scent, and hearing. They have nerve endings in the foreclaws that may make them especially sensitive to touch in their forepaws, but this has not been investigated. Not much is known about communication in these normally solitary animals, but it is likely that home ranges are marked with scents that are used by conspecifics to determine reproductive readiness.

• Communication Channels
• chemical chemical

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Badgers are carnivorous. Their dominant prey are pocket gophers ( Geomyidae ), ground squirrels ( Spermophilus ), moles ( Talpidae ), marmots ( Marmota ), prairie dogs ( Cynomys ), woodrats ( Neotoma ), kangaroo rats ( Dipodomys ), deer mice ( Peromyscus ), and voles ( Microtus ). They also prey on ground nesting birds, such as bank swallows ( Riparia riparia and burrowing owls Athene cunicularia ), lizards, amphibians, carrion, fish, hibernating skunks ( Mephitis and Spilogale ), insects, including bees and honeycomb, and some plant foods, such as corn ( Zea ) and sunflower seeds ( Helianthus ). Unlike many carnivores that stalk their prey in open country, badgers catch most of their food by digging. They can tunnel after ground dwelling rodents with amazing speed. They have been known to cache food.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• insects
• terrestrial non-insect arthropods

• Foraging Behavior
• stores or caches food stores or caches food

Predation

Natural predation on badgers is rare, with young animals being most vulnerable. The primary predators of badgers are humans who are responsible for habitat destruction, trapping, hunting, automobile fatalities, and poisoning. Other reported predators of American badgers include golden eagles ( Aquila chrysaetos ), bobcats ( Lynx rufus ), cougars ( Puma concolor ), and coyotes ( Canis latrans ). Bears ( Ursus ) and gray wolves ( Canis lupus ) may also sometimes take badgers.

Ecosystem Roles

Badgers are important consumers of many small prey items in their ecosystem. They help to control rodent populations, kill venomous snakes, and eat insects and carrion. Their burrows provide shelter for other species and their digging activity helps in soil development.

Badgers and coyotes are sometimes seen hunting at the same time in an apparently cooperative manner. Badgers can readily dig rodents out of burrows but cannot run them down readily. Coyotes, on the other hand, can readily run rodents down while above ground, but cannot effectively dig them out of burrows. When badgers and coyotes hunt in the same area at the same time, they may increase the number of rodents available to the other. Coyotes take advantage of rodents attempting to escape from badgers attacking their burrows and it has been demonstrated that coyotes benefit from the association. Badgers may be able to take advantage of rodents that are escaping coyotes by fleeing into burrows, but it is more difficult to assess whether badgers actually do benefit from this association. Badgers and coyotes tolerate each other's presence and may even engage in play behavior.

• Ecosystem Impact
• creates habitat
• soil aeration soil aeration

Economic Importance for Humans: Positive

Badgers eat many rodent pests, which may carry disease or damage crops. In addition, their burrows provide shelter for small game mammals, like cottontail rabbits . The fur is attractive, it has been used as a trim on Native American garments and historically it was used to make shaving and painting brushes.

• Positive Impacts
• body parts are source of valuable material
• controls pest population

Economic Importance for Humans: Negative

Badger burrows may present a hazard to cattle and horses. Such animals have been known to break legs by stepping into badger holes.

Conservation Status

American badgers are fairly common in appropriate habitats and are not generally considered threatened. In some areas they are uncommon or rare. In Michigan, Wisconsin, Illinois, and British Columbia they are protected from hunting by law.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Allison Poor (editor), University of Michigan-Ann Arbor.

Nancy Shefferly (author), Animal Diversity Web.

References

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

Long, C. 1999. American badger: Taxidea taxus. Pp. 177-179 in The Smithsonian Book of North American Mammals . Washington, D.C.: Smithsonian Institution Press.

Sullivan, J. 1996. "Taxidea taxus" (On-line). USDA Forest Service, Wildlife Species. Accessed September 08, 2006 at http://www.fs.fed.us/database/feis/wildlife/mammal/tata/all.html .

Hoffmeister, D.F. 1989. Mammals of Illinois. University of Illinois Press, Urbana and Chicago.

Nowak, Ronald. 1991. Walker's Mammals of the World. John Hopkins University Press, Baltimore and London.