Great Basin Rattlesnake

Great Basin Rattlesnake

Crotalus viridis lutosus

Size (length): 16-64 inches (40.6-162.6cm)
Habitat: Rocky outcrops, talus slopes, stony canyons, prairie dog towns; below 11,000'
Diet: Small mammals, birds, lizards, snakes, and amphibians
Predators: Hawks and raptors

 

Don't be fooled! This is a Great Basin Gopher Snake doing its best Rattlesnake impression. Note the narrower head and lack of a rattle. The Gopher Snake is not venomous.

General Biology:

The Great Basin Rattlesnake is light brown or gray with a tapering row of brownish blotches down the midline of the back. Scales are large and keeled (not flat and smooth) in 25-27 rows. Their range is from southeast Oregon, southern Idaho, and northeast California, to Nevada, western Utah, and northwest Arizona. It is a subspecies of the Western Rattlesnake.

The Great Basin Gopher Snake, Pituophis melanoleucus, is sometimes mistaken for a rattlesnake, too often motivating irrational fear or unnecessary violence from humans. The two species do have somewhat similar markings but careful observation quickly reveals several obvious differences. The body of a rattlesnake is thicker with flat sloping sides, whereas the gopher snake's body is perfectly round, long, and skinny. Rattlesnakes are also identified by their large triangular heads; gopher snakes' heads are small and bullet-shaped. Most notably, gopher snakes lack the rattle at the end of their tails. Interestingly, they have learned to mimic rattlesnakes by twitching their tails when alarmed. If their tail happens to be resting on some dry leaves, the noise of their tail-twitching can mimic the "buzz"of a rattlesnake's rattle. While this behavior fools a Coyote or fox into leaving the gopher snake alone, it often encourages misguided or malevolent humans to kill it.

 

Behavior:

Rattlesnakes are "sit and wait" predators, meaning they prefer to hide and let prey come to them instead of actively hunting. Rattlesnakes sense their surrounding world in several ways.

• Sight: With forward facing eyes, their vision is more binocular than that of most snakes. This gives them excellent aim and the ability to precisely judge distances when striking. At night, their "infrared night vision" allows them to use special organs on the face called Loreal Pits to detect changes in temperature. This allows it to locate and precisely strike the warm body of a rodent.
• Smell: By collecting molecules on their forked tongues and transferring them to a special receptor on the roof of their mouth called the Jacobson's Organ.
• Feel: Even the vibration of a small mouse tip-toeing through soft sand can be detected.

Rattlesnakes hibernate through the winter in communal burrows. For the Great Basin Rattlesnakes, mating occurs between March and May and sometimes in the fall. Young are live-born, usually between August and October in litter sizes of 4 - 21 young. The record lifespan of a Great Basin Rattlesnake is 19 ½ years.

Rattlesnakes are venomous, meaning they have the potential to inject poison during a bite. However, their first response is to avoid danger by moving away, followed by attempting to threaten a potential danger by shaking its tail to create its rattling sound. If you see a rattlesnake, give it plenty of space (5 feet/1.5 meters or more), and move on. Report sightings, as well as a detailed location description, to a nearby ranger or at the Visitor Center.

Remember: Rattlesnakes are an important part of our ecosystem and it is illegal to harass or kill them.

 

Conservation:

Snakes provoke instinctual fear and/or loathing in humans. All snakes including rattlesnakes are protected animals in National Parks; therefore it is illegal to harass or harm them. In the desert southwest, snakes are a key group of species that control rodent populations. It has been documented that high populations of White-footed Deer Mice lead to deadly Hanta Virus outbreaks. Consider the following reality: While there is no known cure for Hanta Virus, rattlesnake bites are almost never fatal when proper medical treatment is administered. Nationwide, almost half of all rattlesnake bites occur when people are trying to kill, capture, or otherwise harm the snakes. Your safest action is to leave rattlesnakes alone and they will leave you alone.

You can greatly reduce your chance of encountering a rattlesnake by staying on trails. Areas of rocky slopes or lowlands of tall sagebrush should be avoided as they offer shade and cover for snakes and can make them hard to spot.

Rattlesnake bites are seldom fatal. Nevertheless, professional medical care should be sought out as soon as possible. If you have been bitten: Remain as calm as possible as to slow the travel of venom through the body and contact 911 immediately. Remember that a biting snake is responding defensively to your actions. Protect them and yourself by leaving rattlesnakes alone.

 

When to see at Bryce Canyon:

Rattlesnakes can be seen at any time during the warm summer months, but are most commonly spotted around dawn and dusk. Cold winter temperatures keep them out of higher elevations.

Further Reading:

Behler, John L. and F. Wayne King. 1979. National Audubon Society Field Guide to North American Reptiles and Amphibians.

Alfred A. Knopf, Inc., New York, pp. 682, 694-695.

Stebbins, Robert C., Peterson Field Guides: Western Reptiles and Amphibians, 1985: Houghton Mifflin Company, Boston, p. 231-232.

Williams, David. 2000 A Naturalist's Guide to Canyon Country. Falcon Publishing, Inc., Helena, Montana. P155