They also have a high tolerance for warm temperatures and typically avoid shade. Although they can be found in forested landscapes, they seem to have a preference for open habitats where their good vision can most benefit them seeking prey and their speed is unencumbered by abundant debris, especially avoiding predators. Racers inhabit most of the grassland and shrub-steppe ecoysystems of the Southern Interior of the Province. In dry vegetation, this may produce a sound similar to that make by a rattlesnakes rattle. When confronted by a person, racers, like many harmless snakes, sometimes vibrate the tail. Estimated adult annual survivorship was 79% in Utah, 62% in Kansas, 54% in Michigan (Rosen 1991). Population density was estimated to be 0.65/ha in Utah (Brown 1973), up to about 15/ha in Kansas. In South Carolina, summer home range was 5-21 ha (mean 12 ha) movement on active days was 74-135 m (mean 104 m) home ranges overlapped (Plummer and Congdon 1994). Home range size was estimated at 1.4 ha for nongravid females in Utah (Brown and Parker 1976), about 10 ha in Kansas (Collins 1982). Egg laying occurs in June or July and hatchlings emerge in 40 to 60 days (COSEWIC 2004). Clutch size is dependent on female size and condition with an average of 6 eggs in BC, but as many as 12 has been reported (COSEWIC 2004). Adult females reproduce annually or biennially, depending on their condition and are adversely affected by drought. Sometimes this snake nests communally.īreeding occurs during May in the summer range when adult snakes (>3-4 years old) from different dens are most likely to be in contact with each other. Females become sexually mature in 3 years in Utah, 2-3 years in Kansas, 2 years in Michigan (Rosen 1991). Eggs hatch in about 6-9 weeks, generally in August or early September. Clutch size is usually 5-28, averages higher in the east than in the west mean clutch size about 6 in Utah, 12 in Kansas, 15 in Michigan (Rosen 1991). Eggs laying peaks early to mid-June in southern Michigan (Rosen 1991), late June or early July in Utah/Colorado. Adult Racers should not be confused with Rubber Boas, which have no dorsal patterns but have stout bodies, blunt tails, and very small eyes.Įggs laying occurs in June or early to mid-July in most areas. Nightsnakes might also be confused with juvenile Racers but they have vertical eye pupils and short tails. The dorsal skin neonates and yearlings is patterned with a series of saddle markings down its back, resembling a Gophersnake but is easily distinguished by not having any pattern on the tail and the eyes are much larger. The dorsal surface has no pattern in adults and is a olive-green. They have relatively large heads and very large eyes with round pupils. Racers are slender and sleek, sometimes growing to over a metre in length. It was recently treated as its own species (Collins 1991) but has since been recognized as just a subspecies (Crother et al. mormon) is the only subspecies of Racer in BC. Hatchling: upper surface with numerous brown blotches on a paler background eyes relatively huge. Total length up to around 190 cm in the northeastern U.S., much smaller (usually less than 90 cm) in the west. Upper surface of adults varies from black (e.g., northeastern U.S) to plain brown or olive (most of western and central U.S.), with a spattering of white, yellowish, buff, or pale blue in some parts of the south-central United States upper scales smooth (unkeeled) belly black (e.g., northeastern U.S.) to plain yellow or cream (western and central U.S.) eyes large anal scale divided nostril bordered by two separate scales usually 15 dorsal scale rows just anterior to the vent lower preocular scale (lowermost scale in front of the eye) wedged between upper lip scales. Status applied to Coluber constrictor mormon. The CDC reports on this element at the species level, as only one subspecies occurs within the province ( Coluber constrictor mormon). A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BC Conservation Data Centre: Species Summary
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