DISTRIBUTION, ABUNDANCE, AND SEASONALITY

Coachwhips are common to uncommon in arid regions below 2350 m (7700 ft) in California (Stebbins 1985). They are found in the deserts south of Mono Co. and the foothills of the coast ranges south of San Francisco Bay. There is an isolated population in the Sutter Buttes, Sutter Co. (Hayes and Cliff 1982). Coachwhips occur in open terrain and are most abundant in grass, desert, scrub, chaparral, and pasture habitats (Wilson 1970, Stebbins 1972).

SPECIFIC HABITAT REQUIREMENTS

Feeding: Diet consists of rodents, lizards and eggs, snakes (including rattlesnakes), birds and eggs, young turtles, insects, and carrion (Cowles 1946, Stebbins 1954, Wright and Wright 1957, Carpenter 1958, Cunningham 1959, Miller and Stebbins 1964). Coachwhips search actively for prey, with their heads elevated. They poke their heads in burrows, or climb trees, using both vision and olfaction to detect prey (Stebbins 1954, 1985, Miller and Stebbins 1964), which is consumed alive and whole (Ortenburger 1928, Stebbins 1954, 1985).

Cover: Coachwhips seek cover in rodent burrows, bushes, trees, and rock piles (Stebbins 1954, 1985, Miller and Stebbins 1964). They hibernate in soil or sand approximately 0.3 m (1 ft) below the surface, sometimes at the bases of plants (Wright and Wright 1957).

Reproduction: Little is known about nest sites. One was recorded on the bank of a highway drainage ditch, approximately 0.3 m (1 ft) beneath the ground surface (Wright and Wright 1957).

Water: In desert regions, coachwhips may be attracted to water to drink or ambush prey (Miller and Stebbins 1964).

Pattern: Open habitats are preferred.

SPECIES LIFE HISTORY

Activity Patterns: Diurnal. Coachwhips are usually active mid-morning and late afternoon (Miller and Stebbins 1964) from March through October (Wright and Wright 1957).

Seasonal Movements/Migration: No data.

Home Range: No data.

Territory: No data.

Reproduction: Mating occurs in April and May, eggs are laid June and July, and the first young appear in late August or early September (Stebbins 1954, Wright and Wright 1957, Fitch 1970). Clutch size ranges from 4 to 16 eggs with a mean of 8 to 10 (Stebbins 1954, Wright and Wright 1957, Carpenter 1958, Cunningham 1959, Fitch 1970). The incubation period in the lab is 76-79 days (Stebbins 1954).

Niche: Coachwhips are mainly terrestrial, but occasionally climb trees and bushes to bask, seek prey and cover. These aggressive snakes will bite if captured. They are able to move rapidly, up to 12.8km (8 mi) per hour (Stebbins 1954, 1985, Miller and Stebbins 1964). Hawks are probable predators, and roadrunners may feed on young coachwhips.