Robinson, M.L., Conrad, P.M., and Ryan M.M. 2007, Venomous Reptiles of Nevada, Extension, University of Nevada, Reno, SP-07-07

NEVADA’S REPTILES

Approximately 52 species of snakes and lizards share the Nevada landscape with us. Of these, only 12 are considered venomous. Only 6 can be dangerous to people and pets. Encountering them is uncommon because of their body camouflage and secretive nature, which are their first defenses in evading predators. Consider yourself fortunate if you do see one! As with all wildlife, treat venomous reptiles with respect.

Reptiles are ectothermic, meaning their body temperature increases or decreases in response to the surrounding environment. They are most active in the spring, summer and early fall when it’s comfortable, short sleeve weather for us. Reptiles usually hibernate, or brumate, during winter in response to colder temperatures. During high summer temperatures in the Mohave Desert, reptiles may estivate underground in order to maintain vital body temperatures.

In most cases*, collecting Nevada’s native reptiles is not allowed without the appropriate permit, which is issued by the Nevada Department of Wildlife. Please visit www.ndow.org to become familiar with the different types of collection, species allowed, limits and types of permits required by the department.

THE VENOMOUS SNAKES

Nevada is home to 5 snake species that can be dangerous to people and pets. They are all members of the Viperidae family, the pit vipers. They are the Sidewinder, Mohave, Speckled, Western Diamondback and Great Basin rattlesnakes. With the exception of juveniles, most rattlesnakes we encounter in Nevada are 1½ to 4 feet long. It is very important to remember that rattlesnakes do not always rattle their tails in warning a rattle does not always precede a strike!

General Characteristics

All rattlesnakes in Nevada have facial or loreal pits, heat-sensitive depressions, on either side of the head between the nostril and eye. These pits can detect differences in temperatures of less than 0.5° F in nearby objects and aid rattlesnakes in detecting prey even in complete darkness. Compared to most non-venomous snakes, rattlesnakes have broad, triangular shaped heads that accommodate the venom glands and muscles controlling them (see Figures 3 and 4). Pit vipers use fangs to dispense venom, which is a complex toxic compound used both to subdue prey and protect against predators. Having the ability to dispense venom using these fangs can mean life or death for rattlesnakes.

When not in use, fangs are folded against the roof of the mouth. These fangs swing down as the snake lunges forward to strike and venom is dispensed through the fang into the prey. Fangs are not permanent; they are periodically replaced. The flexible jaws allow snakes to swallow their prey whole.

Rattlesnakes have a triangular head that gives way to a narrow neck, thick body, and a tail tipped with a series of inter-locking segments making up the rattle. Every time a snake sheds its skin a new segment is added. Snakes shed from one to three times a year and sometimes rattle segments break off, which is why rattlesnakes cannot be aged by simply counting the rattle segments.

Rattlesnakes do not hatch from eggs; they are born alive from mid-summer to fall. The ability to vibrate the tail is instinctive, but the rattle cannot be heard until juveniles shed at least three times. Remember, juvenile rattlesnakes should not be mistaken as harmless, as they can deliver a fully potent bite and lack the ability to control the amount of venom injected.

For pictures and descriptions of Nevada's venomous snakes use the link below.

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