Eastern Yellow-Bellied Racer

Family: 
Colubridae (nonvenomous snakes) in the order Squamata (lizards and snakes)
Description: 

The color of this common, medium to large, smooth-scaled, slender, snake is uniform but variable—from olive, tan, brown, or blue to gray or nearly black. The belly may be yellow, cream, or light blue gray. Juveniles are tan, strongly marked with closely spaced gray or brown blotches in the middle of the back, and smaller, alternating spots on the sides; the belly is usually cream colored with dark gray speckling. As the young snakes grow, the markings fade and eventually disappear by the third season. When alarmed, racers try to escape quickly and sometimes vibrate their tails. When captured, they struggle violently, bite viciously, and discharge musk and waste matter from their vents.

Similar species: In southeastern Missouri, the eastern subspecies is replaced by the southern black racer subspecies (Coluber constrictor priapus), which is usually uniformly dark gray to bluish black and has a prominent white chin.

Size: 
Length: 30 to 50 inches (76-127 cm).
Habitat and conservation: 
Racers are active March through November. Active during daytime, they live in native prairies, grasslands, pastures, brushy areas, and along the edges of forests. In spring and fall, they occur on rocky, wooded, south-facing hillsides, which is where they overwinter (in caves), if they do not overwinter in a mammal burrow in an open habitat. Racers will hide under rocks, brush, or in animal burrows if pursued. As the name implies, racers can move fast, especially through tall grass or brush.
Foods: 
Food includes frogs, lizards, small snakes, small rodents, birds, and insects. Racers are not constrictors. They use their speed and agility to overtake prey—as well as to escape their own predators.
Distribution in Missouri: 
The eastern yellow-bellied racer subspecies occurs nearly statewide. In southeastern Missouri, it is replaced by the southern black racer subspecies.
Status: 
Many Missourians know yellow-bellied racers as "blue racers."
Life cycle: 
Courtship and mating occur soon after these snakes emerge from overwintering retreats, usually in early April. Egg-laying is in mid-June to late July. The female lays 8-21 eggs under logs, in rotten stumps, or in abandoned mammal burrows. The eggs hatch in 2-3 months.
Human connections: 
For as long as there have been humans, snakes have captured our imaginations. In myth, religion, and story, snakes perform the role of seducer, sneak, guardian, healer, killer, and transformer. They symbolize power, wisdom, sexuality, and life itself, and have been worshiped and reviled.
Ecosystem connections: 
Racers are predators of many small animals, but as with many other predatory species, they can be preyed upon themselves by other predator animals, including larger mammals and by birds such as hawks. The eggs and young are especially vulnerable.