Coluber constrictor foxii

Blue racers prefer open and semi-open habitats, savanna, old field shoreline, and edge habitats. A mosaic of these habitats is likely required to fulfill the ecological needs of C. c. foxii.

In the United States: Ohio, Indiana, Illinois, Michigan, Wisconsin, South Dakota, and Iowa are the only states with extant populations of blue racer. The last reliable record of the blue racer on mainland Canada was in Ontario in 1983. On Pelee Island in Ontario, the blue racer is restricted to the eastern two-thirds of the island.

Blue racers often have creamy white ventral scales, dull grey to brilliant blue lateral scales, and pale brown to dark grey dorsum. They also have characteristic black masks, relatively large eyes, and often have brownish-orange rostral scales (snouts). Unlike adults, hatchlings and yearlings (first full active season) have dorsal blotches that fade completely by the third year; however, juvenile patterning is still visible on the venter until late in the snake's third season.

Juvenile

Adult

The blue racer is one of Ontario's largest snakes, reaching 90 cm to 152 cm snout-to-vent length (SVL). The largest documented specimen captured on Pelee Island was 138 cm SVL. Although there has been some controversy regarding the designation of C.c. foxii as a subspecies distinct from C.c. flaviventris (the eastern yellow-bellied racer), most recent authorities agree that the subspecies C.c. foxii is valid.^[1]

Blue racers are active foragers. The younger snakes may eat crickets and other insects, whereas adults feed primarily on rodents, songbirds and other snakes. Adults engage in both terrestrial and arboreal foraging. Blue racers are diurnally active. Probable natural predators of adult blue racers include the larger birds of prey (e.g., red-tailed hawk, northern harrier, great horned owl) and carnivorous mammals such as raccoons, foxes and coyotes. Dogs and feral house cats are known to kill and/or harass juvenile blue racers. The eggs and young are likely vulnerable to a wider variety of avian and mammalian predators.^[1]

Blue racer

seem to be relatively intolerant of high levels of human activity and for most of the active season, they remain in areas of low human density.

Evidence to suggest this comes largely from radio telemetry data from both blue racers and eastern fox snakes that inhabited the same general areas on Pelee Island (although studies were not conducted concurrently). In contrast to blue racers, eastern fox snakes were often found under front porches, in barns/garages, and in the foundations of houses; whereas, most (but not all) blue racers were observed in more "natural" settings. Therefore, blue racers are more confined to areas with minimal anthropogenic activity. Campbell and Perrin also noted that racers were among the first snakes to disappear from suburban areas.^[1]

The blue racer is oviparous and the average clutch size for seven females is 14.7 ± 2.53. Females can reproduce annually, but biennial cycles are likely more common. Males can mature physiologically at 11 months, but do not have the opportunity to mate until their second full year; similarly, females may mature at 24 months but are not able to reproduce until the following year. Mating begins in April and continues throughout May. Females oviposit in late June and eggs hatch from mid-August to late-September. The most common nesting microhabitats used by female blue racers are fallen decaying logs; however, eggs are also laid under large rocks and in mounds of decaying organic matter. Intra- and interspecific (with the eastern fox snake) communal nest sites have been documented and appear to be relatively common.^[1]