The bull snake is a common name for a race of snakes in the same species more commonly known as gopher snakes. The race termed bull snakes occurs in eastern New Mexico and up through the Great Plains and Midwestern states. The eight other races of snakes in this species are referred to as gopher snakes. The Sonoran gopher snake occurs throughout most of central and western New Mexico and interbreeds with the bull snake in areas of population overlap.
These snakes are non-poisonous and kill their prey by constricting. They are rather large snakes, reaching eight feet in length. Bull and gopher snakes take small mammals, such as ground squirrels, gophers, mice and rats, and rabbits. They also prey on ground-nesting birds and their eggs, as well as other reptiles. The coloration and pattern of dark spots resemble the prairie rattler, and the defensive behavior of gopher snakes also involves a hissing, rattling sound produced in the trachea that mimics the rattler’s alarm warning. The head may also be flattened when the snake is threatened, making it resemble the triangular head shape of a rattler. A quick glance at the smooth, pointed tail will serve to positively identify a bull or gopher snake and distinguish it from a rattlesnake.
Bull snakes breed in early spring and lay from a few to two dozen eggs. The young hatch out after about 10 weeks and are on their own, able to hunt without assistance from the parents. The juveniles are in the greatest danger of falling prey to predators during this early period. A variety of prairie predators eat gopher snakes, such as foxes, coyotes and hawks. Gopher snakes serve an important ecological function in helping control rodent populations. Gopher snake populations are vulnerable in areas where natural grasslands and prairies are being converted for croplands, industrial development or urban landscapes.
Gopher snakes are active during the day in cooler weather, basking in a sunny area to absorb heat in order to become fully mobile. In warmer weather they will hunt at night. Gopher snakes hibernate during winter in rock dens or underground burrows. I once watched one slithering along quickly in the grass beside a gravel road and then disappear head first into a hole. The burrow must have been large because the snake dove into it at full speed until it disappeared. These snakes will also sometimes come around residences but can be easily and safely moved to a nearby lot or pasture using a long pole to suspend the snake while carrying it. I have relocated a bull snake from my front porch to a pasture across the street this way.