Family: Boidae, Boas view all from this family
Description 14-33" (35.6-83.8 cm). Looks rubbery. Short broad snout and short blunt tail give it a two-headed appearance. Uniformly olive-green, reddish-brown, or tan to chocolate-brown. Large scales on top of head. Eyes small with vertical pupils. Scales smooth, in 32-53 rows. Anal plate single. Adult males have well-developed anal spurs; small spurs in females usually hidden.
Subspecies Northern Rubber Boa (C. b. bottae), dorsal color of adults usually olive-green to medium brown; average total length over 16" (400 cm). Southern British Columbia through Washington, Idaho, Oregon, and mountains of California, eastward through northern Nevada, northern and central Utah, and western Wyoming and Montana. Isolated populations in Bighorn Mountains of central Wyoming and Montana.
Southern Rubber Boa (C. b. umbratica), smaller than C. b. bottae, usually less than 16" (40 cm) long; lighter in color, mainly tan; larger scales. San Bernardino and San Jacinto Mountains of Southern California.
In southern California (southern Sierra Nevada, Tehachapi Mountains, and Mount Pinos), some specimens display characteristics of both subspecies -- they are smaller than typical C. b. bottae, and darker than typical C. b. umbratica. These populations are considered to be intergrades.
Breeding Live-bearing; 2-8 young, 7" (17.8 cm) long, are born late August to September.
Habitat Damp woodland and coniferous forest, large grassy areas, meadows, and moist sandy areas along rocky streams. Sea level to 9,200' (2,800 m).
Range British Columbia to s. California and eastward to Montana, Wyoming, and Utah.
Discussion Crepuscular and nocturnal. An accomplished burrower, it retreats under rocks or into damp sand, hollow rotting logs, or forest litter. Also a good swimmer and climber; its prehensile tail enables it to climb shrubs and small trees. A constrictor, it preys on small mammals, birds, and lizards. It is docile and curls into ball when picked up. Captive longevity exceeds 11 years.
