Eastern racer


The eastern racer (Coluber constrictor) is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America and Central America. Eleven subspecies, including the nominotypical subspecies, are recognized, which as a group are commonly referred to as the eastern racers. The species is monotypic in the genus Coluber.

C. constrictor is found throughout the United States, east of the Rocky Mountains, but it also ranges north into Canada and south into Mexico, Guatemala, and Belize.

Adult eastern racers can typically vary from 50 to 152 cm (20 to 60 in) in total length (including tail) depending on the subspecies, but a record-sized specimen measured 185.4 cm (73.0 in) in total length.[4][5][6] A typical adult specimen will weigh around 556 g (1.226 lb), with little size difference between the sexes.[7] The patterns vary widely among subspecies. Most are solid-colored as their common names imply: black racers, brown racers, tan racers, blue racers, or green racers. "Runner" is sometimes used instead of "racer" in their common names. All subspecies have a lighter-colored underbelly: white, light tan, or yellow in color. Juveniles are more strikingly patterned, with a middorsal row of dark blotches on a light ground color. The tail is unpatterned. As they grow older, the dorsum darkens and the juvenile pattern gradually disappears.[4]

The eastern racers are fast-moving, highly active, diurnal snakes. Their diet consists primarily of small rodents, frogs, toads, lizards, and other snakes.[8] Some subspecies are known to climb trees to eat eggs and young birds. Juveniles often consume soft-bodied insects, such as crickets and moths[citation needed]. Despite their specific name, constrictor, they do not really employ constriction, instead simply subduing struggling prey by pinning it bodily, pressing one or two coils against it to hold it in place instead of actually suffocating it. Most smaller prey items are simply swallowed alive.

They are curious snakes with excellent vision and are sometimes seen raising their heads above the height of the grass where they are crawling to view what is around them. Aptly named, racers are very fast and typically flee from a potential predator. However, once cornered, they put up a vigorous fight, biting hard and often. They are difficult to handle and will writhe, defecate, and release a foul-smelling musk from their cloacae. Vibrating their tails among dry leaves, racers can sound convincingly like rattlesnakes.[9]

C. constrictor is found frequently near water, but also in brush, trash piles, roadsides, and swamps, and in suburbia; it is the most common snake in residential neighborhoods in Florida. It spends most of its time on the ground, but it is a good tree climber and may be found in shrubs and trees where bird nests can be raided for eggs and chicks, as well as small adult birds such as finches, canaries, and thrashers.


Closeup of head of C. c. mormon, western yellow-bellied racer
Closeup of the head of Coluber constrictor constrictor, northern black racer