Tuesday 21 May
Western diamond-backed rattlesnake (Crotalus atrox)
What’s the World’s Favourite Species?Find out here.
Western diamond-backed rattlesnake fact file
- Find out more
- Print factsheet
Western diamond-backed rattlesnake description
An iconic reptile, the rattle of the western diamondback rattlesnake is one of the most evocative sounds of the arid southern United States (3). A large and heavy-bodied species, the western diamond-backed rattlesnake’s colouration varies from chalky grey to dull red, appearing dusty due to minute flecks and dots on the scales. As suggested by its common name, this species has diamond-shaped markings over most of its body, which are edged with black and white (2). These markings are replaced by conspicuous black and white bands towards the rear of the tail, just in front of the rattle (2) (4), while the head has two characteristic pale stripes, one in front of the eye and the other behind, which run diagonally down the head towards the mouth (2). Undoubtedly, the most distinctive feature of this species is the rattle. This unusual appendage is composed of loosely-connected, interlocking segments made of dead, horny keratin, which knock together when the tail is vibrated, producing the rattling sound (4) (5). Newborn rattlesnakes are born without a rattle, but acquire segments after each moult, eventually developing as many as ten (4) (5).
- Also known as
- Western diamondback rattlesnake. Top
- The Humane Society of the United States (September, 2009)
- In snakes, a process of growth, in which the outer layer of the skin is shed allowing the body to become larger.
- IUCN Red List (September, 2009)
- Dixon, J.R., Werler, J.E. and Levoy, R. (2005) Texas Snakes: A Field Guide. University of Texas Press, Austin.
- O'Shea, M. (2008) Venomous Snakes of the World. New Holland Publishers, London.
- Burnie, D. (2001) Animal. Dorling Kindersley, London.
- Werler, J.E. and Dixon, J.R. (2000) Texas Snakes: Identification, Distribution, and Natural History. University of Texas Press, Austin.
- Degenhardt, W.G., Painter, C.W. and Price, A.H. (2005) Amphibians and Reptiles of New Mexico. UNM Press, Albuquerque.
- Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
- Taylor, E.N. and Denardo, D.F. (2005) Reproductive Ecology of Western Diamond-Backed Rattlesnakes (Crotalus atrox) in the Sonoran Desert. Copeia, 2005: 152 - 158.
- The Humane Society of the United States (September, 2009)
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
Western diamond-backed rattlesnake biology
An efficient predator of small mammals, birds and lizards, the western diamond-backed rattlesnake hunts by ambush (4), laying in wait around burrows or runs (6). In addition to locating prey by sight and smell, this species also detects body-heat by means of heat-sensitive pits between the eyes and nostrils. When in range, prey is dispatched with a rapid strike, delivering a large quantity of highly toxic venom, which kills the animal within seconds (4). In addition to its toxic effects, the venom also has a role in digestion, and within 24 hours of the prey being ingested, the venom will have broken down the skin and begun to digest the internal organs (7). While the western diamond rattlesnake will usually attempt to escape from potential threats, when cornered, this species will give the characteristic warning rattle, raise its head and the anterior of its body, and may strike if further provoked (4). This species is active during the night in the summer, but extends its activity into the cooler times of day during the spring and autumn (7). During the winter the western diamond-backed rattlesnake undergoes a process analogous to hibernation in mammals, called brumation, in which the low environmental temperatures reduce the snake’s metabolic rate and limit its activity. During this time, the western diamond-backed rattlesnake may form large aggregations in upland areas, which shelter in dens located in abandoned mines, caves, or rock crevices (1) (7).
The western diamond-backed rattlesnake has two breeding periods, the first occurring in the spring, and the second in late summer/autumn. Sperm from the latter period may be stored in the female’s body throughout the winter before being used to fertilise the eggs (8). The western diamond-backed rattlesnake bears live young, and litters may number from 4 to 61 offspring (3). The newborn snakes are well-developed, and already equipped with fangs and toxic venom, but do not reach sexual maturity until three to four years old (4).Top
Western diamond-backed rattlesnake range
The western diamond-backed rattlesnake inhabits the southern USA, and northern and central Mexico. In the USA, it can be found in south-eastern California, southern Nevada, Arizona, New Mexico, Texas, Oklahoma and Arkansas, while in Mexico, it occurs in extreme north-east Baja California, and northern states, south as far as Veracruz, and possibly Oaxaca (1)Top
Western diamond-backed rattlesnake habitat
The western diamond-backed rattlesnake can be found in arid and semi-arid habitats, including desert, plains, rocky hills, grassland, shrubland, woodland, dried river beds and coastal islands. It ranges from lowland regions to mountainous areas, at elevations of up to 2,440 metres above sea level, but typically occurs below 1,500 metres (1).Top
Western diamond-backed rattlesnake status
Classified as Least Concern (LC) on the IUCN Red List (1).Top
Western diamond-backed rattlesnake threats
With a wide range and a relatively stable population exceeding 100,000 adults, there is little threat to the western diamond-backed rattlesnake at present. Nevertheless, severe regional declines have occurred as a result of habitat destruction, road traffic, hunting and persecution. Organised hunts known as “rattlesnake roundups” occur in some states, with the aim of ridding the area of rattlesnakes (1). The hunts have been criticised on the basis that they not only disrupt the ecosystem, by removing an important rodent predator, but also use methods that are environmentally destructive and impact non-target species (9).Top
Western diamond-backed rattlesnake conservation
While there are currently no known conservation measures specifically targeting the western diamond-backed rattlesnake, this species occurs in several protected areas throughout its range (1).Top
Find out more
To learn more about the issues surrounding “rattlesnake roundups” visit:
AuthenticationThis information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: email@example.comTop
More »Related species
Play the Team WILD game
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.