CSG Species Accounts: Bobcat (Lynx rufus)

Description and Behavior
The bobcat, named for its short tail (TL=13-20 cm; 13-16% of head-body length: Hall 1981), is a medium-sized cat with a ruff of fur edging the sides of the face. The average weight of adult males ranges from 8.9-13.3 kg, and females from 5.8-9.2 kg (Anderson 1987). The largest verifiable weight recorded is 17.6 kg for an adult male from Minnesota (Berg 1979). Average adult weights and cranial measurements (Samson 1979) indicate that bobcats are larger in the north of their range (Anderson 1987); larger bobcats also tend to occur in more open habitats, with smaller bobcats in forested habitat (Read 1981). Pelt coloration has been variously described as light grey, yellowish brown, buff, brown and reddish brown. Bobcats are always spotted to some extent, with some individuals patterned only on the undersides, others with spots extending up the sides onto the chest and back. Both melanistic and albinistic specimens have been reported (Schantz 1939, Ulmer 1941, Young 1958) -- melanism has been found only in Florida (Regan and Maehr 1990). The bobcat may be distinguished from the similar-looking Canada lynx by its shorter hind legs, smaller feet, and shorter ear tufts. The bobcat’s tail is black only on the top, whereas the lynx has black all around the tip.
However, as with the lynx, lagomorphs are the bobcat’s year-round dietary staple -- cottontail rabbits in the south of their range, and snowshoe hares in the north (Maehr and Brady 1986, Anderson 1987, Rolley 1987). Unlike the specialist lynx, however, the bobcat is a generalist and, depending on the locality, rodents also make an important contribution to its diet (Young 1958). In the southern Central Plains and the southern United States, cotton rats are the primary food item (Kight 1962, Beasom and Moore 1977, Miller and Speake 1978, McCord and Cardoza 1982, Leopold and Krausman 1986, Maehr and Brady 1986). Wood rats and kangaroo rats are important in the south-western US (Leach and Frazier 1953, Gashwiler et al. 1960, Small 1971, Jones and Smith 1979). In western Washington state, Knick et al. (1984) reported a 42% occurrence of mountain beaver in the diet. In Texas, peccaries are also taken (Leopold and Krausman 1986). Bobcats also take birds (Leach and Frazier 1953, Beasom and Moore 1977, Miller and Speake 1978, Bailey 1979) and bats (Wroe and Wroe 1982).
Despite their small size, bobcats can be effective predators of large adult ungulates, especially deer, generally killed when resting (Matson 1948, Young 1958). Several studies have found that males tend to consume larger prey than females (Fritts and Sealander 1978a, Sweeney 1978, Litvaitis et al. 1984), and that juveniles consume proportionally more rodents than adults (Whittle 1979, Toweill 1982). Ungulates can be an important winter food source for northern bobcats, when snow depth increases their vulnerability to predation (Erickson 1955, Fritts and Sealander 1978a, Miller and Speake 1978, May 1981, Litvaitis et al. 1986, Koehler and Hornocker 1989). Young fawns are also particularly vulnerable (Beale and Smith 1973, Trainer 1975). Bobcats will also scavenge ungulate carcasses killed by other predators (Koehler and Hornocker 1991).
Bobcats may be active during all hours of the day and night, but studies have consistently found crepuscular (dawn and dusk) activity peaks, a pattern based on the activity patterns of major lagomorph and rodent prey species (reviewed by Anderson 1987, Rolley 1987).