Desert Habitat

March 12, 2002

Western Rattlesnake
Crotalus viridis

Description: This snake's length ranges from 15 to 65 inches. The snakes body is usually very stout. It has a triangular head that is wider than the neck. The skin on the snake has dark brown or black, diamond shaped blotches on a lighter background. The rattle is found on the snake's tail. Rattlesnakes may be found in rocky outcrops along canyon rims.

Diet: Eats mainly small mammals such as mice, ground squirrels and rabbits but may also consume birds and lizards

Reproduction: Young are born in the late summer or early fall. Litter size increases with female size. Studies have shown that the level of fat reserves in females will determine whether or not they produce a litter each year or every other year.

Interesting and Unique: The rattle on the snake is a series of dry, flattened, interlocking segments that produces a buzzing sound when shaken. A new segment is added each time the snake sheds its skin, which can occur up to 4 times per year. Rattlesnakes have a set of hollow fangs which fold back along the jaw; these fangs spring forward allowing the snake to immobilize its prey by injecting a poisonous venom. The venom is a mixture of proteins that act on blood and muscle tissue. The snake also has heat sensitive pits on its head which helps it to locate warm-blooded prey.