Author: Anne Schultz

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Scientific Name: pituophis catenifer sayi
Common Name: bullsnake, gopher snake
Spanish Name: víbora sorda

Herpetologists don't agree completely on the classification of bullsnakes: some use the scientific name Pituophis melanoleucus, and others refer to this snake as Pituophis catenifer.

Bullsnakes are large, heavy-bodied snakes. Adults are typically 3 to 5 feet long. Their bodies are yellowish or tan, with between 33 and 66 brown or reddish blotches reaches from head to tail. The blotches on the tail often have a more regular, banded appearance.

Their bellies are yellow or creamy white, with black spots

Geographic range:
Bullsnakes are found throughout North America: they are known to occur from southern Canada into Mexico, and are found from New Jersey California.

Bullsnakes are probably the most widespread snake in New Mexico. They have been found in dry deserts at elevations of 3000 feet and in mixed conifer forests at much higher elevations (90,000 feet!). They are commonly found in areas where lots of small mammals also live. They live here because rodents and other mammals are a food source and because they will also use their old burrows for shelter.

Food Web:
Bullsnakes eat a variety of small mammals like voles, shrews, rabbits, and ground squirrels are common. These snakes will also feed on birds and their eggs, frogs, and lizards. Bullsnakes are constrictors, which means that they squeeze their food until they die, but they may also swallow small animals without killing them first. These snakes can be helpful to farmers and ranchers, because they hunt rodents that are often considered pests!

Reproduction and Development:
Bullsnakes can reproduce when they are three or four years old. Mating happens in the spring, when the snakes emerge from hibernation. Males may compete for opportunities to mate with females, sometimes by participating in a ritualized fight with each other. Neither participant is usually hurt, but the two snakes coil around each other, and each one tries to force his opponent's body and head lower to the ground. The snake that maintains the upper position wins the fight, and the loser retreats. The winner then might get a chance to mate.

Mating occurs in early spring. By late June or July, the female lays a clutch of five to twenty eggs. Young snakes will hatch in late summer or early fall – usually in August or September. The hatchlings are between 8 and 18 inches, and are grayish in color until they shed their skin for the first time.

Bullsnakes are active mainly during the day, but it is not unusual to see them in the evenings or at night. During the hottest parts of the summer, they are actually more active at night.

Some people confuse bullsnakes – which are not poisonous – with rattlesnakes, because the defensive behavior and appearance of both snakes is alike. Bullsnakes will show defensive behavior when threatened. They flatten their head, puff up their bodies and coil up. They will also hiss and shake their tails.

Ecosystem roles:
Bullsnakes are important in controlling the population size of small mammals, particularly rodents. Since bullsnakes are common predators in the habitat of the deer mouse, which is commonly the habitat for the Hantavirus, because they eat the animals the animals that may be i nfected with the virus.

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Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Family: Colubridae
Genus: Pituophis
Species: Pituophis melanoleucus

Degenhardt, William G., Charles W. Painter, and Andrew H. Price. 1996. Amphibians and Reptiles of New Mexico. Albuquerque: University of New Mexico Press.

Stebbins, Robert C. 2003. A Field Guide to Western Reptiles and Amphibians. New York: Houghton Mifflin Company.

Related Terms: pituophis catenifer sayi, víbora sorda, gopher snake