Western diamond-backed rattlesnake

Scientific Name: Crotalus atrox

When the western diamond-backed rattlesnake is threatened, it will shake its rattle in warning. The rattle, which is at the end of the tail, is made from keratin, and each time the snake moults, a new segment is added. Although the bite of the western diamond-backed rattlesnake has caused a lot of fatalities, it will not actively attack, but bites in defence. Venom is injected quickly via long, hollow, retractable fangs. The tail of the snake next to the rattle is banded with black and white stripes, but the rest of its body is brown to grey, sometimes pinkish in colour with dark brown diamond blotches trimmed in white. This solid snake grows to 1.5 metres long.


Found in the south-west United States and central Mexico, the western diamond-backed rattlesnake favours dry, rocky terrain with some trees, cacti and shrubs. It will often hide in rocky crevices and burrows and during winter will hibernate in these – even if the burrows are occupied by prairie dogs or other western diamond-backed rattlesnakes.


Small mammals, birds, reptiles and amphibians. The snake is an ambush predator, keeping coiled up and still, waiting for the prey to pass for it to strike. If the prey is land bound, such as rodents, the snake will bite and release, then follow the scent trail to where the prey has died once the venom has kicked in. Birds are generally not released as they don’t leave a trail to follow. Prey is swallowed whole and the snake only eats every 2-3 weeks.


Snakes are mature at about 3 years and mating takes place in spring when the snakes come out of hibernation. After a gestation period of 167 days, the females give birth to 10-20 live young. Within a few hours of being born, the young scatter off in search of prey.