American badger

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American badger
Taxidea taxus (Point Reyes, 2007).jpg
In Point Reyes National Seashore, California
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Subfamily: Taxideinae
Genus: Taxidea
Waterhouse, 1839
Species: T. taxus
Binomial name
Taxidea taxus
(Schreber, 1778)
American Badger area.png
American badger range

The American badger (Taxidea taxus) is a North American badger, somewhat similar in appearance to the European badger. It is found in the western and central United States, northern Mexico, and south-central Canada to certain areas of southwestern British Columbia.

American badger habitat is typefied by open grasslands with available prey (such as mice, squirrels, and groundhogs). The species prefers areas such as prairie regions with sandy loam soils where it can dig more easily for its prey.

Taxonomy[edit]

The American badger is a member of the Mustelidae, a diverse family of carnivorous mammals that also includes the weasel, otter, ferret, and wolverine.[2] The American badger belongs to the Taxidiinae, one of three subfamilies of badgers - the other two being the Melinae (9 species, including the Eurasian badger) and the Mellivorinae (honey badger). The American badger's closest relative is the prehistoric Chamitataxus.

Recognized subspecies include: the nominate subspecies T. t. taxus, found in central Canada and central US; T. t. jacksoni, found in the southern Great Lakes region including southern Ontario; T. t. jeffersoni, in British Columbia and the western US; and T. t. berlandieri, in the southwestern US and northern Mexico.[3][4] Ranges of subspecies overlap considerably, with intermediate forms occurring in the areas of overlap.

In Mexico, this animal is sometimes called tlalcoyote. The Spanish word for badger is tejón, but in Mexico this word is also used to describe the coati. This can lead to confusion, as both coatis and badgers are found in Mexico.

Description[edit]

American badger

The American badger has most of the general characteristics common to badgers; with stocky and low-slung bodies with short, powerful legs, they are identifiable by their huge foreclaws (measuring up to 5 cm in length) and distinctive head markings. Measuring generally between 60 to 75 cm (23.6 to 29.5 inches) in length, males of the species are slightly larger than females (with an average weight of roughly 7 kg (15.5 pounds) for females and up to almost 9 kg (19.8 pounds) for males). Northern subspecies such as T. t. jeffersonii are heavier than the southern subspecies. In the fall, when food is plentiful, adult male badgers can exceed 11.5 kg (25.3 pounds).[5]

American badger

Except for the head, the American badger is covered with a grizzled, brown, black and white coat of coarse hair or fur, giving almost a mixed brown-tan appearance. The coat aids in camouflage in grassland habitat. Its triangular face shows a distinctive black and white pattern, with brown or blackish "badges" marking the cheeks and a white stripe extending from the nose to the base of the head. In the subspecies T. t. berlandieri, the white head stripe extends the full length of the body, to the base of the tail.[6]

Diet[edit]

The American badger is a fossorial carnivore. It preys predominantly on pocket gophers (Geomyidae), ground squirrels (Spermophilus), moles (Talpidae), marmots (Marmota), prairie dogs (Cynomys), pika (Ochotona), woodrats (Neotoma), kangaroo rats (Dipodomys), deer mice (Peromyscus), and voles (Microtus), often digging to pursue prey into their dens, and sometimes plugging tunnel entrances with objects.[7] They also prey on ground-nesting birds, such as the bank swallow or sand martin (Riparia riparia) and burrowing owl (Athene cunicularia), and lizards, amphibians, carrion, fish, skunks (Mephitis and Spilogale), insects, including bees and honeycomb, and some plant foods such as corn (Zea mais), peas, green beans, mushrooms and other fungi, and sunflower seeds (Helianthus).

Behavior[edit]

American badgers are generally nocturnal, but have been reported to be active during the day. In remote areas with no human encroachment, badgers are routinely observed foraging during the day. Seasonally, however, a badger observed during daylight hours in the Spring months of late March to early May often represents a female badger, foraging during daylight to then return and stay with her young at night. Badgers do not hibernate, but may become less active in winter. A badger may spend much of the winter in cycles of torpor that last around 29 hours. They do emerge from their burrows when the temperature is above freezing.[4]

Badger burrows that are abandoned may then be occupied by foxes, skunks or animals of similar size. Abandoned badger burrows also provide ready-made homes for burrowing owl, California Tiger Salamander and California Red-Legged Frog. A misconception about badgers and coyotes is reflected in the human projected perception that badgers and coyotes form a mutually beneficial relationship in hunting and foraging. In fact, the benefit is for the coyote. Coyotes are not as effective in digging prey out of burrows and will remain in proximity to a foraging badger, to then capture prey if it escapes the badger's claw-paws. Widely reported has been the misconception that badgers and coyotes hunt together. Badgers are solitary foragers and coyotes who observe badgers in the process of seeking prey will position themselves in proximity in order to attempt to capture any prey that eludes a badger in its attempt to escape.

Life cycle[edit]

Badgers are normally solitary animals for most of the year, but are thought to expand their territories in the breeding season to seek out mates. Males may breed with more than one female. Mating occurs in late summer and early fall. American badgers experience delayed implantation. Pregnancies are suspended until December or as late as February. Young are born from late March to early April.[4] Litters range from one to five young,[8] averaging about three.[9]

Badgers are born blind, furred, and helpless.[4] Eyes open at four to six weeks. The female feeds her young solid foods prior to complete weaning, and for a few weeks thereafter.[9] Young American badgers first emerge from the den on their own at five to six weeks old.[8][10] Families usually break up and juveniles disperse from the end of June to August; young American badgers leave their mothers as early as late May or June.[10] Juvenile dispersal movements are erratic.[8]

American badger at Omaha's Henry Doorly Zoo

Most female American badgers become pregnant for the first time after they are a year old. A minority of females four to five months old ovulate and a few become pregnant. Males usually do not breed until their second year.[4]

Major causes of adult American badger mortality include, first and foremost, loss of habitat and habitat fragmentation, preventing the ability to move through a normal range, and then automobiles, ranchers and farmers (by various methods), sport shooting, and fur trapping. Identifying habitat areas preferred by adult female badgers for breeding, birthing and raising young are critically important to support biodiversity in the context of climate change impacts, loss of habitat and competition among species for habitat areas as coastal wildlife migrate inland, seeking cooler temperatures in upland habitat areas that often represent established habitat for American Badger. Large predators occasionally kill American badgers.[8] The average longevity in the wild is 9–10 years and the record is 14 years;[11] a captive American badger lived at least 15 years and five months.[8]

Habitat[edit]

American badgers occur primarily in grasslands and open areas with grasslands, which can include parklands, farms, and treeless areas with friable soil and a supply of rodent prey.[12][13] They may also be found in forest glades and meadows, marshes, brushy areas, hot deserts, and mountain meadows. They are sometimes found at elevations up to 12,000 feet (3,600 m) but are usually found in the Sonoran and Transition life zones (which are at elevations lower and warmer than those characterized by coniferous forests).[9] In Arizona, they occur in desert scrub and semidesert grasslands.[14] In California, American badgers are primarily able to survive through a combination of open grasslands of agricultural lands, protected land trust and open space lands, and even regional and state and national park lands with grassland habitat. An identified population in South Sonoma County fragilely survives with areas of abundant prey, but threatened from fragmentation. The Sonoma County badger population also includes some protected and private lands near the Sonoma Coast. Badgers are occasionally found in open chaparral (with less than 50% plant cover) and riparian zones. They are not usually found in mature chaparral.[15] In Manitoba aspen parklands, American badger abundance was positively associated with the abundance of Richardson's ground squirrels (Spermophilus richardsonii).[16]

Badgers can be found in the sagebrush deserts of eastern Oregon.

American badger use of home range varies with season and sex. Different areas of the home range are used more frequently at different seasons and usually are related to prey availability. Males generally have larger home ranges than females. In a study almost 40 years ago, radiotransmitter-tagged American badgers had an average annual home range of 2,100 acres (850 ha). The home range of one female was 1,790 acres (725 ha) in summer, 131 acres (53 ha) in fall, and 5 acres (2 ha) in winter.[17] Lindzey reported average home ranges of 667 to 1,550 acres (270–627 ha).[18] In 2014, severe fragmentation of American Badger habitat from over-development of land and blockage of wildlife movement areas equate to the range of a badger being significantly influenced by available land for habitat and foraging as well as the ability to move within a preferred range. Direct observations in Sonoma County, documenting habitat and badger sightings and foraging, reflect various ranges within the fragmented habitat areas from less than 1/2 mile to approximately 4 miles. Within these areas, the availability of prey and a fresh water source are key factors for the preferred habitat areas and ability to survive. Identifying and conserving habitat areas where there is year-round activity, along with identified burrowing patterns and observations of female badger territory for birthing and raising young have become critical factors in survival of the species.

Estimated density of American badgers in Utah scrub-steppe was one per square mile (2.6 km2), or 10 dens per square mile (assuming a single American badger has 10 dens in current or recent use).[4]

The American badger in Ontario, is restricted primarily to the extreme southwestern portion of the province – largely along the north shore of Lake Erie in open areas generally associated with agriculture and woodland edges. There have been a few reports from the Bruce-Grey region.[19]

Plant communities[edit]

American badgers are most commonly found in treeless areas, including tallgrass and shortgrass prairies, grass-dominated meadows and fields within forested habitats, and shrub-steppe communities. In the Southwest, plant indicators of the Sonoran and Transition life zones (relatively low, dry elevations) commonly associated with American badgers include creosotebush (Larrea tridentata), junipers (Juniperus spp.), gambel oak (Quercus gambelii), willows (Salix spp.), cottonwoods (Populus spp.), ponderosa pine (Pinus ponderosa), grasses, and sagebrushes (Artemisia spp.).[9]

In Colorado 37 years ago, American badgers were common in grass–forb and ponderosa pine habitats.[20] In Kansas, they are common in tallgrass prairie dominated by big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), and Indian grass (Sorghastrum nutans).[21] In Montana 24 years ago, badgers were present in Glacier National Park in fescue (Festuca spp.) grasslands.[22] In Manitoba, they occur in grassland extensions within aspen (Populus spp.) parklands.[16]

Cover requirements[edit]

American badgers enlarge foraged out gopher holes or other prey holes or burrows to create a burrow for sleeping and concealment, protection from weather, and natal dens; burrows range from about 4 feet to 10 feet in depth and 4 feet to 6 feet in width. A female American Badger may create 2 to 4 burrows in proximity with a connecting tunnel for concealment and safety for her young. Displaced soil from digging out the burrow characteristically appears in front of the burrow entrance, and a view from a distance reveals a mound-like roof of the burrow, with the living and concealment space created underneath the raised-roof appearing mound. During summer and autumn, badgers range more frequently, with mating season generally in November, and burrowing patterns reflect 1 to 3 burrows may be dug from foraged out prey holes in a day, used for a day to a week, and then abandoned, with possible returns later, and other small wildlife utilizing abandoned burrows in the interim. Where prey is particularly plentiful, they will reuse dens,[9] especially in the fall, sometimes for a few days at a time. In winter, a single den may be used for most of the season.[4] Natal dens are dug by the female and are used for extended periods, but litters may be moved, probably to allow the mother to forage in new areas close to the nursery. Natal dens are usually larger and more complex than diurnal dens.[8]

Predators[edit]

The American badger is an aggressive animal and has few natural enemies. Predation on smaller individuals by golden eagles (Aquila chrysaetos), coyotes,[4] cougars (Felis concolor), and bobcats (Lynx rufus) have been reported.[23] Bears (Ursus spp.) and gray wolves (Canis lupus) occasionally kill American badgers.[8]

Conservation status[edit]

In May 2000, the Canadian Species at Risk Act listed both the Taxidea taxus jacksoni and the T. t. jeffersonii subspecies as an endangered species in Canada.[24] The California Department of Fish and Game designated the American badger as a California species of special concern.[25]

See also[edit]

References[edit]

 This article incorporates public domain material from the United States Department of Agriculture document "Taxidea taxus".

  1. ^ Reid, F. & Helgen, K. (2008). Taxidea taxus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 21 March 2009. Database entry includes a brief justification of why this species is of least concern
  2. ^ Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. p. 619. ISBN 978-0-8018-8221-0. OCLC 62265494. 
  3. ^ "Taxidea". Retrieved 2007-08-07. 
  4. ^ a b c d e f g h Long, Charles A. (1972). "Taxidea taxus". Journal of Mammalogy 26: 1–4. doi:10.2307/3504047. Archived from the original on 13 July 2007. Retrieved 2007-08-07. Long, Charles A. (1972). "Taxonomic Revision of the North American Badger, Taxidea taxus". Journal of Mammalogy (Journal of Mammalogy) 53 (4): 725–759. doi:10.2307/1379211. JSTOR 1379211. 
  5. ^ Feldhamer, George A.; Bruce Carlyle Thompson; Joseph A. Chapman (2003). Wild Mammals of North America: Biology, Management, and Conservation. JHU Press. p. 683. ISBN 0-8018-7416-5. 
  6. ^ American Society of Mammalogists Staff; Smithsonian Institution Staff (1999). The Smithsonian Book of North American Mammals. UBC Press. p. 179. ISBN 0-7748-0762-8. 
  7. ^ Michener, Gail R. (2004). "Hunting techniques and tool use by North American badgers preying on Richardson's ground squirrels". Journal of mammalogy 85 (5): 1019–1027. doi:10.1644/BNS-102. JSTOR 1383835. 
  8. ^ a b c d e f g Lindzey, Frederick G. (1982). Badger: Taxidea taxus. In: Chapman, Joseph A.; Feldhamer, George A., eds. Wild mammals of North America: Biology, management, and economics. Baltimore, MD: The Johns Hopkins University Press: 653–663
  9. ^ a b c d e Long, Charles A.; Killingley, Carl Arthur. 1983. The badgers of the world. Springfield, IL: Charles C. Thomas Publishing
  10. ^ a b Messick, John P.; Hornocker, Maurice G. (1981). "Ecology of the Badger in Southwestern Idaho". Wildlife Monographs 76 (76): 1–53. JSTOR 3830719. 
  11. ^ Lindsey, Frederick G. 1971. Ecology of badgers in Curlew Valley, Utah and Idaho with emphasis on movement and activity patterns. Logan, UT: Utah State University
  12. ^ Banfield, A. W. F. 1974. The mammals of Canada. Toronto, ON: University of Toronto Press
  13. ^ de Vos, A. 1969. Ecological conditions affecting the production of wild herbivorous mammals on grasslands. In: Advances in ecological research. [Place of publication unknown]: [Publisher unknown]: 137–179. On file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT
  14. ^ Davis, Russell; Sidner, Ronnie. 1992. Mammals of woodland and forest habitats in the Rincon Mountains of Saguaro National Monument, Arizona. Technical Report NPS/WRUA/NRTR-92/06. Tucson, AZ: The University of Arizona, School of Renewable Natural Resources, Cooperative National Park esources Study Unit
  15. ^ Quinn, Ronald D. 1990. Habitat preferences and distribution of mammals in California chaparral. Res. Pap. PSW-202. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station
  16. ^ a b Bird, Ralph D. (1930). "Biotic communities of the aspen parkland of central Canada". Ecology 11 (2): 356–442. doi:10.2307/1930270. JSTOR 1930270. 
  17. ^ Sargeant, Alan B.; Warner, Dwain W. (1972). "Movements and denning habits of a badger". Journal of Mammalogy 53 (1): 207–210. doi:10.2307/1378851. 
  18. ^ Lindzey, Frederick G. (1978). "Movement patterns of badgers in northwestern Utah". Journal of Wildlife Management 42 (2): 418–422. doi:10.2307/3800282. JSTOR 3800282. 
  19. ^ "Ontario Badgers". ontariobadgers.org. 
  20. ^ Morris, Meredith J.; Reid, Vincent H.; Pillmore, Richard E.; Hammer, Mary C. 1977. Birds and mammals of Manitou Experimental Forest, Colorado. Gen. Tech. Rep. RM-38. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment.
  21. ^ Gibson, David J. (1989). "Effects of animal disturbance on tallgrass prairie vegetation". American Midland Naturalist 121 (1): 144–154. doi:10.2307/2425665. JSTOR 2425665. 
  22. ^ Tyser, Robin W. 1990. Ecology of fescue grasslands in Glacier National Park. In: Boyce, Mark S.; Plumb, Glenn E., eds. National Park Service Research Center, 14th annual report. Laramie, WY: University of Wyoming, National Park Service Research Center: 59–60
  23. ^ Skinner, Scott. 1990. Earthmover. Wyoming Wildlife. 54(2): 4–9
  24. ^ "Species at Risk Act: List of Wildlife Species at Risk accessdate=14 March 2013". 
  25. ^ "Mammal Species of Special Concern". dfg.ca.gov. Archived from the original on 23 November 2010. Retrieved 27 November 2010. 

Further reading[edit]

External links[edit]