Believe it or not, you can find TWO types of rattlesnakes in Idaho!
But please don’t live in fear, thinking that you are going to be bitten. In general, rattlesnakes try to avoid any contact or interaction with people. The whole reason they have a rattle is to warn you to stay away! As long as you leave them alone, you shouldn’t have any trouble.
*If you come across any of these species, PLEASE DO NOT DISTURB! Rattlesnakes are dangerous animals and should be left alone. The more you agitate them, the more likely you could get bitten. DO NOT RELY ON THIS ARTICLE to correctly identify a rattlesnake that has recently bitten you. If you have recently been bitten, GO DIRECTLY to the nearest hospital to get help and determine if the snake is venomous.*
RELATED: The 8 Types of SNAKES Found in Idaho! (ID Guide)
#1. Prairie Rattlesnake
- Crotalus viridis
- Adults typically range between 3.3 and 5 feet in length.
- Coloration is highly variable and can be greenish-gray, olive green, greenish-brown, light brown, or yellow. All variations have dark blotches on the body that turn into rings near the tail.
- Broad triangular head, elliptical pupils, and a tail rattle.
These rattlesnakes can be found in Idaho in open prairies, grasslands, semi-desert shrublands, and forested environments. They can even be found at elevations up to 9500 feet (2900 m)!
The Prairie Rattlesnake hibernates during the winter, often in communal dens. These dens are typically rock crevices, caves, or old mammal burrows. Individual snakes will return to the same den each winter and migrate up to seven miles to their hunting grounds in the spring.
When they feel threatened, these snakes will freeze, using their camouflage to avoid detection. They may also quietly crawl away to cover. If approached, they may coil and rattle their tail as a warning before striking. Their potent venom has both hemotoxic and neurotoxic properties and, although rare, can be fatal to an adult human.
Prairie Rattlesnakes are listed on the ICUN Red List as a species of least concern. However, they are considered threatened and declining in parts of their range. Their biggest threats are pressures from habitat fragmentation and hunting.
#2. Western Rattlesnake
- Crotalus oreganus
- Adult size varies widely over their range, with the largest individuals being 6 feet long.
- Coloration varies greatly and can be dark brown, yellowish, dark gray, or olive-brown.
- Triangular head. A dark stripe with white borders that runs from the eye towards the jaw.
Also known as the Northern Pacific Rattle Snake, this species occupies a wide range of habitats. They can be found in mountainous areas, woodlands, and grasslands. They often occur in close proximity to humans.
Western Rattlesnakes have excellent camouflage and unique coloring, as these snakes show considerable variation. When they’re young, they have a distinct color pattern, but it fades over time as the snakes mature.
These snakes may be active during the day or night and are often curled, waiting to ambush various prey. They’ll feed on small mammals, birds, reptiles, and amphibians. They may also eat bird eggs, and young snakes often feed on insects.
Like other rattlesnakes, this species gives birth to live young. Healthy, sexually mature females can give birth to up to 25 babies!
Do you need additional help identifying a rattlesnake?
I recommend purchasing a Peterson Field Guide to the Reptiles and Amphibians of North America. These books have lots of helpful information, including pictures and range maps.
Which of these rattlesnakes have YOU seen before in Idaho?
Leave a comment below!