Western Diamondback Rattlesnake

Crotalus atrox

Summary 5

The western diamondback rattlesnake or Texas diamond-back (Crotalus atrox) is a venomous rattlesnake species found in the southwestern United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S. No subspecies is currently recognized.

Description 6

VENOMOUS. Rough, sharply-keeled scales, broad head on a narrow neck, vertical slit pupils. Stocky body has a brown to tan diamond shaped pattern down the back, ending with alternating black and white before the rattle. Diamond pattern is not always conspicuous, can vary in different individuals. Two parallel pale stripes separated by a darker stripe extends diagonally across the cheeks to the eyes. Typically 3 to 4 feet (91 to 122cm) long. (J. R. Dixon and J. E. Werler, Texas Snakes: A Field Guide, University of Texas Press, 2000.)

Coloration: 7

Background coloration of tan or brown surrounds series of diamond-shaped blotches.
Dorsal coloration varies tremendously over its distributional range, though typically shades of tan or brown.
Tail is black and white banded (sometimes called "coontail" across its range).
Ventral surface is off-white and usually unmarked.

Behavior: 7

All rattlesnakes are venomous, and therefore potentially dangerous if approached or handled. Rattlesnakes are not generally aggressive and will most likely flee if given a chance to retreat. The western diamond-backed rattlesnake is primarily a nocturnal animal, hunting for its prey on warm summer nights. It is, however, seasonally diurnal, moving between hunting sites during the day during the cooler spring and fall months. The western diamond-backed rattlesnake is usually inactive between late October and early March, though an occasional rattlesnake may be seen sunning itself on warm winter days.

Habitat: 7

Found from the flatlands and prairies to the rocky hills and low mountains, the western diamond-backed rattlesnake is a key participant in the food web; it is an important predator of many small rodents, rabbits, and birds. The western diamond-backed rattlesnake is in turn preyed upon by a variety of larger mammals and birds, such as coyotes, foxes, and hawks.

General Distribution: 7

In the United States, Crotalus atrox is found in California, Arizona, New Mexico, Oklahoma and Texas. The western diamond-backed rattlesnake also has an extensive range in the northern half of Mexico.

Texas Distribution: 7

In Texas, Crotalus atrox is found throughout the state, save the wettest eastern portions of the state. Its relative, the eastern diamond-backed rattlesnake (Crotalus adamanteus), is found in eastern Louisiana and ranges from there through Florida to North Carolina.

Conservation Status: 7

The western diamond-backed rattlesnake is not a protected species in Texas and can be legally collected with a hunting license.

Sources and Credits

  1. (c) J. N. Stuart, all rights reserved, uploaded by J. N. Stuart, http://www.flickr.com/photos/stuartwildlife/9574741923/
  2. (c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda
  3. (c) Matt Muir, some rights reserved (CC BY), uploaded by Matt Muir
  4. (c) showmejoe, some rights reserved (CC BY-NC-SA), uploaded by showmejoe, https://picasaweb.google.com/109872954484795521115/RubyArizona#5385786684286239794
  5. Adapted by Desmon M Dunn from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Crotalus_atrox
  6. (c) Amber Leung, some rights reserved (CC BY-SA), https://www.inaturalist.org/guide_taxa/494736
  7. (c) Caleb Paul, some rights reserved (CC BY-SA), https://www.inaturalist.org/guide_taxa/776635

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