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Canadian Herpetological Society Société d'Herpétologie du Canada |
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Blue Racer
Coluber constrictor foxii
Family: Colubridae
The Blue Racer is a subspecies of the North American Racer (Coluber constrictor).
COSEWIC status:- Endangered
- Endangered
- Least Concern
Description
The Blue Racer is tan, pale blue or bluish green with a white or bluish belly and a dark “mask” may be visible around the eyes. Young juveniles are well-patterned with a series of dark-bordered, brown, red, or grey blotches over a grey to tan background. The dorsal scales are smooth and it has a divided anal plate. Individuals can grow to almost 2 m in length.
Similar Species
As an adult this species is the only large, bluish snake in Ontario. The Smooth Greensnake, however, often turns bluish after death. The often light grey to black Lake Erie Watersnakes have a stout body, usually with some remnants of darker or lighter bands and keeled scales. Young Blue Racers may be confused with young Lake Erie Watersnake or Eastern Foxsnake, the only species with a blotched pattern that live alongside Blue Racers on Pelee Island. Eastern Foxsnakes have weakly keeled scales and a checkered belly, and Lake Erie Watersnakes have keeled scales and may have full bands, partial bands or be mostly grey, instead of having dark-bordered blotches.
Distribution
Click for larger image
Although the Blue Racer once occurred on the Ontario mainland, its Canadian distribution is now limited to Pelee Island, in Lake Erie. This subspecies also occurs south of the Great Lakes in Ohio and west to Iowa. The various subspecies of the North American Racer occur in southern Saskatchewan, southern British Columbia and throughout almost all U.S. states, in Mexico and south to Guatemala.
Habitat
The Blue Racer inhabits grasslands, fields, savannah and open woodlands. Rocks, logs and other cover objects are important microhabitats that provide retreat and thermoregulation sites. Individuals overwinter below the frost line in mammal burrows, rock crevices, anthropogenic structures (e.g. old foundations, cisterns) and other underground cavities. Females lay their eggs in rotting logs, stumps, vegetation or mounds of decaying matter, under rocks or in animal burrows.
Biology
Blue Racers breed in the spring and females lay an average of 15 leathery eggs, sometimes communally. The eggs hatch in late summer, and the young are 20–30 cm in length. Individuals may reproduce each year, but most likely only reproduce every two years in Canada. Individuals of this species reach maturity in two to three years and can live for more than 20 years. As its name suggests, the Blue Racer is a very fast snake and can move at a speed of almost 7 kph. The Blue Racer eats insects, frogs, other snakes, small rodents and birds. Blue Racers may hibernate communally in large groups.
Threats
Habitat loss on Pelee Island due to conversion of land to agricultural use has been the largest threat to the Canadian Blue Racer population. Fortunately, much of this species’ habitat on the island is now protected by provincial nature reserves and land trusts. However, some threat of development persists on private lands and ongoing succession of habitats in protected areas is resulting in ongoing decline of this species’ habitat. Road mortality and human persecution continue to threaten this small population.