Bull Snake

Taxobox
name = Bull Snake


regnum = Animalia
phylum = Chordata
classis = Reptilia
ordo = Squamata
subordo = Serpentes
familia = Colubridae
genus = "Pituophis"
species = "P. catenifer"
subspecies = "P. c. sayi"
trinomial = "Pituophis catenifer sayi"
trinomial_authority = Schlegel, 1837

Bull Snake is a species ("Pituophis catenifer") and also a subspecies ("Pituophis catenifer" sayi) of large non-venomous colubrid snake, widespread in the western half of the United States and northern Mexico. The epithet "sayi" is in honor of the renowned zoologist Thomas Say.

The species also goes by the name Gopher Snake. For a list of P. catenifer subspecies, see Pituophis.

It is inconvenient for the bull snake species to have the same common name as the bull snake subspecies. The solution is to speak of the "bull snake species" or the "bull snake subspecies" whenever the distinction is important, or to use the formal Latin names. Similar situations are not particularly unusual in taxonomy. A familiar example is the nightshade family (Solanaceae) and the nightshade genus (Solanum).

This article covers the species as a whole; differences between one subspecies and the next are minor.

Range

Bull snakes have one of the most expansive ranges of any species in the "Pituophis" genus. They can be found throughout much of the western half of United States and northern Mexico. This includes the U.S. states of Texas, New Mexico, Arizona, Utah, Oklahoma, Idaho, Oregon, Washington, Iowa, Illinois, Missouri, Colorado, Kansas, Minnesota, North Dakota, South Dakota, Nebraska, California, Wyoming, Montana, Wisconsin, and Nevada.

Description

Bull snakes often exceed convert|6|ft|m|1 in length, and specimens of up to convert|100|in|cm|0 have been recorded. This makes them among the largest US snakes, although generally not as long as indigo snakes or as big around as rattlesnakes. Males are generally larger than females. They are usually yellow in color, with brown, black or sometimes reddish colored blotching. The blotching pattern is as follows: fat blotches on top, three sets of spots on the sides, and bands of black on the tail. Many color variations have been found, including albinos and white varieties.

Diet

Bull snakes eat small mammals, such as mice, rats, large bugs, as well as ground nesting birds, lizards, and the young of other snakes. Juvenile bull snakes depend on insects, small lizards and baby mice.

(The idea that bull snakes occasionally eat rattlesnakes is sometimes touted as a reason for humans not to harm bull snakes when encountering them in the wild, although a better reason is the bull snake's role in controlling warm-blooded vermin such as rodents. Note that many snakes have a natural immunity to venom, just as rattlesnakes themselves are immune to their own. Some venomous snakes are being reaserched for the already antivenin inside their bodies to be used for medical purposes.)

Behavior

Though some bull snakes can be docile, and with some time become accustomed to handling, most bull snakes are quite defensive and known for their perceived "bad attitude".

When threatened by anything as large as a human, a bull snake's primary defense is to flee, if possible.

Bull snakes are often confused for rattlesnakes, and killed by laypersons. Due to its coloration, dorsal pattern, and semi-keeled scalation; the Bullsnake superficially resembles the Western Diamondback Rattler ( "Crotalus atrox" ), which is also common within the same range. The bull snake capitalizes on this similarity by performing a very impressive rattlesnake impression when threatened. First, it hisses, or forcibly exhales through a bisected glottis, which flaps back and forth producing a very convincing "rattle" sound. It will also take on a rattlesnake-like "S-curve" body posture, as if it is going to strike. The bull snake will commonly vibrate its tail rapidly amongst the brush or leaves, and flatten its head to make it take on a more characteristic triangular-shaped head of the rattlesnake. These defensive behaviors are meant to scare away threats, not sound an attack.

In contrast to rattlesnakes, which usually keep their tail elevated in order to sound the most efficient rattle, bull snakes tend to keep their tail in contact with the ground, in order to beat it against something to make a sound.

Their rattlesnake mimic is so impressive that it is frequently the bull snake's very undoing when discovered by humans.

Bull snakes customarily kill their prey by constriction before consuming it.

References

* Genus Pituophis
* [http://www.elaphe.it/pituophis.htm Keeping and Breeding of Bull Snake]

External links

* [http://www.herpnet.net/Iowa-Herpetology/reptiles/snakes/bullsnake.html Bull Snake Species account from the Iowa Reptile and Amphibian Field Guide]
* [http://www.exotic-pets.eu/snakes/bullsnake.php Bull snakes in captivity]
* [http://depts.washington.edu/natmap/facts/gopher_snake_712.html Gopher Snake Facts & Photos]

Gallery