from the Midwest, Canadian prairie provinces, and northeastern parts of the United States and Canada (Rosatte and Lariviere 2003). (Colorado typically has few cases of rabies in skunks.) Canine distemper and leptospirosis are also common in skunks. Vehicles and deliberate persecution account for many losses. In areas with a high incidence of rabies, skunks are often eliminated in control efforts during epizootics (Rosatte 1987). Brinkerhoff, Ray, et al. (2008) found that skunks from foothills habitats near Boulder carried a richer assemblage of fleas than did skunks from adjacent grasslands; specifically, a number of species of fleas typical of rodents were found on skunks from the foothills but were absent from skunks in the grasslands. This suggests that striped skunks are associated with rock squirrels and/or woodrats (either as predators or as commensals). Further, it highlights the potential importance of mesocarnivores as potential vectors of flea-borne zoonotic diseases in complex landscapes. Fur trappers take thousands of striped skunks annually even though the value of the pelt is usually no more than $3 to $6 (Rosatte and Lariviere 2003). In Colorado, annual harvest in the late 1930s and early 1940s averaged more than 12,000 animals; more recently harvest has usually been several thousand animals per year, depending on value offurs (J. Fitzgerald 1993b). In the past decade and more, average harvest is estimated at about 1, 150 (Table 4-3 ). Colorado has a 4-month season on the striped skunk as a furbearer and small game species. Literature on the species was reviewed by Godin (1982), Wade Smith and Verts (1982), Rosatte (1987), and Rosatte and Lariviere (2003).
Conepatus leuconotus WHITE-BACKED HOG-NOSED SKUNK
Description
The white-backed hog-nosed skunk is a large skunk with a white back and black sides and venter. The muzzle and sides of the face are black and lack a white
D1git1zed by Google nose stripe. The nose is extended into a naked, flexible snout, hence the name "hog-nosed." The tail is usually completely white and proportionally shorter in length than that of the striped skunk. The fur is shorter and harsher than that of either the spotted or striped skunks. The claws on the front feet are long and stout. Measurements are: total length 450-900 mm; length of tail 190-290 mm; length ofhindfoot 55-77 mm; length of ear 24-27; weight 1,500-4,500 g. The skull is highest in the parietal region, with the auditory bullae moderately inflated. The palate extends posteriorly past the plane of the molars and only 2 premolars are present on each side of the upper jaw. Females have 6 mammae.
PHOTOGRAPH 12-24. White-backed hog-nosed skunk (Conepatus leuconotus). Photograph by Joseph G. Hall.
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This skunk reaches its northern limits in extreme southeastern Colorado and ranges southward into Central America. The species is known from Colorado on the basis of 13 specimens and 1 clear track. The track and 2 skulls were recorded in 1996, 1997, and 2000 in Fremont, Baca, and Custer counties, respectively; all previous records were from the period 1922 to 1932 (Meaney, Ruggles, and Beauvais 2006). H. Donoho (in the early 1980s) and J. Fitzgerald (in 1991) sent questionnaires to Colorado Division of Wildlife personnel regarding the species. No reliable observations came from these inquiries, although one division biologist believed the species still occupied oakbrush-
o1git1zed by Goog le pinon habitats near Rye, Colorado (J. Fitzgerald 1993b ). Chris Pague, chief conservation scientist with The Nature Conservancy in Colorado, photographed a road-killed hog-nosed skunk on Raton Pass, 1.3 km south of the Colorado state line on Interstate 25, in March 2003. Limited data from New Mexico (Meaney, Ruggles, and Beauvais 2006) showed slightly higher harvest of animals in recent years. It may be that the species is on a slight rebound in Colorado and New Mexico; however, significant effort will have to be expended to determine its status. The hog-nosed skunk in Colorado and the Oklahoma Panhandle (Caire et al. 1989) may represent a population disjunct by several hundred kilometers from their next nearest locality, in the Sandia Mountains of New Mexico (Findley et al. 1975). The present status of the species in Colorado is unknown. Two subspecies have been previously named from Colorado: Conepatus mesoleucus jremonti from El Paso and Fremont counties and C. m. jigginsi from Baca County. D. Armstrong (1972) regarded the subspecific designations with skepticism but had inadequate data for a substantive conclusion. Dragoo et al. (2003) suggested that they represent 1 subspecies (C. leuconotus jigginsi) and argued that the subspecies warrants special management.
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MAP 12-47. Distribution of the white-backed hog-nosed skunk (Conepatus leuconotus) in North America.
o1git1zed by Goog le • 0 1() 20 JO 40 50 • ---M!~~ MAP 12-48. Distribution of the white-backed hog-nosed skunk (Conepatus leuconotus) in Colorado.
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This is a species of rocky canyon country of the Southwest: pinon-juniper woodlands, oakbrush, shrublands with cactus, and montane shrublands; it also has been reported from desert and grassland environments (Dowler et al. 2005; Ebeling 2006; Meaney, Ruggles, and Beauvais 2006). In Colorado the few records are associated with oakbrush and pinon-juniper woodlands or oakbrush/ ponderosa pine. Beauvais and Smith (2005) modeled potential habitat in Colorado. Hog-nosed skunks are thought not to thrive in contact with humans.
o1git1zed by Goog le This was once thought to be the commonest skunk species in Texas but it has declined drastically (Rosatte and Lariviere 2003; Meaney, Ruggles, and Beauvais 2006). Little information exists on the life history of the species. In Texas, they were observed to feed mostly on terrestrial insects, with beetles seeming to be of particular importance (Meaney, Ruggles, and Beauvais 2006). However, they also consumed carrion, small reptiles and mammals, and vegetable material, including prickly-pear fruit, berries, and nuts (V. Bailey 1932; W. B. Davis 1974; R. Patton 1974). They seemed to spend much of their time rooting for insects with the snout and long front claws. This rooting activity leaves large areas of disturbed litter and topsoil and is a good clue to their presence (F. Miller 1925). A difficulty in studying hog-nosed skunks is their apparent lack of interest in investigating the bait stations and baited traps commonly used in investigations of other carnivores (Meaney, Ruggles, and Beauvais 2006). Hog-nosed skunks are thought to be solitary and mostly nocturnal (Meaney, Ruggles, and Beauvais 2006). They use rocky ledges, caves, abandoned mines, abandoned burrows, woodrat nests, and similar sites for denning. In Arizona they construct large, mounded grass nests up to a meter high in old mine shafts or caves, and they occupy woodrat dens (Hoffmeister 1986). It is not known whether they enter dormancy seasonally at their northern limits in Colorado. Most of their geographic range is far enough south that the animals can be active year-round. This is a species that might expand its range in Colorado with ongoing climate change. Reproductive biology is not well-known. In Texas, mating occurs in late February (R. Patton 1974), with young born in April or May. Gestation takes 42 to 60 days, with litter size averaging 3. S. Ferguson et al . (1996) speculated that delayed implantation does not occur in the species. Young reach adult size by August and are thought to be sexually mature by 11 months (Meaney, Ruggles, and Beauvais 2006). Mortality factors and population dynamics are poorly understood, although roadkill appears to be significant in some areas and feral pigs may compete for foods in parts of the range. Literature on this species was reviewed by W. Howard and Marsh (1982); Rosatte (1987); Rosatte and
D1git1zed by Google Lariviere (2003); Meaney, Ruggles, and Beauvais (2006); and Dragoo and Sheffield (2009). The species is considered a non-game mammal in Colorado (Colorado Division of Wildlife 2009c).
F "I P . d R R. t "I d K"
The family Procyonidae includes small to medium-sized carnivores with pointed snouts and, in many species, long tails ringed with contrasting colors and distinctive facial markings. The ears are small to medium-sized, and the face is typically short and broad. The feet have 5 digits with well-developed claws, variously non-retractile or retractile. The foot posture is plantigrade or semi plantigrade. The number of teeth ranges from 36 to 40, with the loss of some premolars. The dental formula is 3/3, 1/1, 4/4, 2/2 = 40 teeth for Coloradan species. The incisors are unspecialized. Typical of carnivores, the canines are well developed. The carnassials, however, are poorly developed. The molars are often broad and somewhat triangular or rounded. The stomach is simple, and a cecum is absent. Most procyonids are good climbers, typically sheltering in trees or rock crevices. They are crepuscular or nocturnal and omnivorous in their diets. The species are social to varying degrees; some are solitary, some form pairs, and others live in family groups. Females are monoestrous, having a single estrous cycle during a restricted breeding season. Males are typically about one-fifth larger than females and have a well-developed baculum. The Procyonidae is a rather old lineage, dating from the Oligocene Epoch in North America, approximately 40 million years ago. Procyon and Bassariscus both are known from Miocene deposits (Savage and Russell 1983). Procyonids appear to be closely related to the Ursidae. There are 6 genera and 14 species in the Procyonidae, all restricted to the New World. In Colorado there are 2 genera, each represented by a single species. The Asian red panda (Ailurus julgens) was included within the Procyonidae for many years. Flynn et al.
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