Taxidea taxus (Schreber, 1777) Waterhouse, 1839

Don E. Wilson & Russell A. Mittermeier, 2009, Mustelidae, Handbook of the Mammals of the World – Volume 1 Carnivores, Barcelona: Lynx Edicions, pp. 564-656 : 621

1.

American Badger

Taxidea taxus

French: Blaireau d’Amérique / German: Amerikanischer Dachs / Spanish: Tejon americano

Taxonomy. Ursus taxus Schreber, 1778,

Canada.

Four subspecies are recognized.

Subspecies and Distribution.

T. t. taxus Schreber, 1778 — S Canada (Alberta, British Columbia, Manitoba, Ontario & Saskatschewan) and NC USA.

T. t. berlandieri Baird, 1858 — N & C Mexico and SC USA (W of the Mississippi River).

T. t. jacksoni Schantz, 1946 — NE USA (Great Lakes Region).

T. t. jeffersonii Harlan, 1825 — W USA (NW to California).

Descriptive notes. Head-body 42-72 cm, tail 10-15.5 cm; weight 7.6-8.7 kg (males), 6.3-7.1 kg (females), adult males weigh on average 25% more than females. The American Badger’s body appears flat dorso-ventrally, with a flat head, and shorttail and limbs. The upperparts are grayish-white to yellowish-brown orsilvery black; the underparts are buffy. The feet are dark brown to black. Black patches are present on the face, cheeks, chin, and throat. A dorsal white stripe runs from the nose to the neck, and in some populations, to the rump. The claws on the forefeet are long and strong. There are four pairs of mammae. The skull is wedge-shaped, almost triangular. Dental formula: 13/3,C1/1,P3/3,M1/2=34

Habitat. American Badgers are found in grasslands, prairie habitats, shrubs and steppes, and open woodlands. In British Columbia, they prefer open range and agricultural habitats that have fine sandy-loam and well-drained soils.

Food and Feeding. The diet includes small mammals (especially marmots, ground squirrels, prairie dogs, pocket gophers, cottontail rabbits, mice, voles, chipmunks, and squirrels), birds, eggs, reptiles, amphibians, and invertebrates (insects and molluscs). Carrion is also eaten. In British Columbia, the six main prey species are the Columbian Ground Squirrel (Spermophilus columbianus), Yellow-bellied Marmot (Marmota Slaviventris), Northern Pocket Gopher (Thomomys talpoides), Muskrat (Ondatra zibethicus), Southern Red-backed Vole (Myodes gapperi), and Meadow Vole (Microtus pennsylvanicus). In south-eastern Wyoming, prairie dogs were found in 57% of stomach and fecal samples from female American Badgers. The most common food item in the diet in west-central Minnesota and south-eastern North Dakota is small mammals (98%, primarily Muridae and Geomyidae). Other prey includes insects (40%), and birds and eggs (32%, mostly ducks Anatidae ). Reptiles, amphibians and molluscs are also eaten, but are less common than other foods. Insects and birds’ eggs are more common in the diet during spring (April-May) than summer (June-July). Birds are more frequent in the diets of adults than juveniles. In South Dakota, 40% of stomach contents were mammals, 35% were of plant origin, 10% were birds, 10% were insects, and the remainder was mostly inorganic materials. American Badgers obtain most of their food by excavating the burrows of fossorial animals. If large prey is taken, such as a rabbit, the badger may dig a hole, carry in the prey, and remain below ground with it for several days. There are reports of American Badgers forming a “hunting partnership” with Coyotes. The Coyote apparently usesits keen sense of smell to locate burrowing rodents and the American Badger digs them up with its powerful claws. Both predators then share the proceeds. The techniques used by American Badgers when hunting Richardson’s Ground Squirrels (Spermophilus richardsonii) have been observed. They frequently hunted hibernating squirrels in the autumn, sometimes hunted infants in the spring, but rarely hunted active squirrels in the summer. They always captured hibernating and active squirrels underground, but sometimes intercepted fleeing squirrels aboveground. The most common hunting technique used was excavation of the burrow, but plugging of openings accounted for 5-23% of hunting actions. Plugging occurred predominantly in mid-June to late July, before most ground squirrels hibernated, and in late August to late October when juvenile males were active, but other squirrels were in hibernation. American Badgers usually used soil from around the tunnel opening or soil dragged 30-270 cm from a nearby mound to plug tunnels. Theykill ground squirrels with a single grasping bite directed dorsally or laterally to the thorax. The canines and third upper incisors generally only bruise the skin, without puncturing it, but cause extensive hemorrhaging in the thoracic cavity. Food items are sometimes buried and eaten later.

Activity patterns. Mainly nocturnal, but can be active at any hour. American Badgers rest underground in burrows; these are either self-excavated or are modified burrows that were initially made by another animal. The burrow can be as long as 10 m and can extend 3 m below the surface. A bulky nest of grass is located in an enlarged chamber; the entrances are marked by mounds of earth. American Badgers are active all year, but during severe winter weather they may sleep in the den for several days or weeks.

During this period of inactivity, heart rates are reduced by 50% and the body temperature decreases by 9 °C.

Movements, Home range and Social organization. Daily movement may exceed 10 km and dispersal movements may be greater than 100 km. Mean home range size is up to 12- 3 km? for males and up to 3-4 km? for females. Home ranges overlap, but adults are solitary except during the breeding season. In Utah, mean home range size was 5-83 km? the mean size of female home ranges (2-37 km?) was less than half that of the males. In Idaho, mean home range size was 2-4 km? for males and 1-6 km? for females. In south-eastern Wyoming, the mean home range size of females (3-4 km?) was smaller than that of males (12- 3 km?); mean overlap was less for females than for males, and the mean home rangesize of males was larger during the breeding season than during the non-breeding season (breeding = 11- 1 km?non-breeding = 5- 4 km?). A radio-tracked female in Minnesota used an area of 752 ha during the summer. She had 50 dens within this area and was never found in the same den on two consecutive days. In the autumn, she shifted to an adjacent area of 52 ha and often reused dens. In the winter, she used a single den and traveled infrequently within an area of 2 ha. Population density may be as high as 5/km?. In south-eastern Wyoming, the density varies between 0-8-1-1/km?.

Breeding. Mating occurs in late July or August. Implantation ofthe fertilized eggs into the uterus is delayed until December—February, and births take place in late March or early April. The total gestation period is about seven months; actual embryonic development is about six weeks. Litter size is one to five, usually two. The young are born underground in a nest of dry grass. They are weaned at aboutsix weeks and disperse soon after. Some young females may mate in the first breeding season following birth, when they are about four months old; males wait until the following year.

Status and Conservation. Classified as Least Concern in The IUCN Red List. American Badgers are considered common. Although this species haslittle importance in the fur trade,it is harvested for its fur in many parts of its range. American Badgers are also persecuted because of the damage they do to pasture and agricultural land.

Bibliography. Anderson & Johns (1977), Armitage (2004), Azevedo et al. (2006), Eldridge (2004), Goodrich & Buskirk (1998), Harlow (1981), Hart & Trumbo (1983), Hoodicoff (2006), Lampe (1982), Lindzey (1978, 2003), Long (1973), Long &Killingley (1983), Messick & Hornocker (1981), Michener (2004), Michener & Iwaniuk (2001), Minta (1993), Minta et al. (1992), Murie (1992), Sargeant & Warner (1972), Sovada et al. (1999), Van Vuren (2001), Wozencraft (2005).

Figures

1. American Badger (Taxidea taxus), 2. Honey Badger (Mellivora capensis), 3. Hog Badger (Arctonyx collars), 4. Japanese Badger (Meles anakuma), 5. Asian Badger (Meles leucurus), 6. European Badger (Meles meles)

Subspecies and Distribution. T. t. taxus Schreber, 1778 — S Canada (Alberta, British Columbia, Manitoba, Ontario & Saskatschewan) and NC USA . T. t. berlandieri Baird, 1858 — N & C Mexico and SC USA (W of the Mississippi River). T. t. jacksoni Schantz, 1946 — NE USA (Great Lakes Region). T. t. jeffersonii Harlan, 1825 — W USA (NW to California).