Western diamondback rattlesnake

Western diamondbacks eat small animals.

They catch mice, rats, rabbits and birds. They wait very still until food comes close.

Western diamondbacks eat mostly small mammals, such as mice, rats and rabbits, and birds, and sometimes lizards or frogs. They are ambush hunters: a rattlesnake finds a good spot, often at dusk, and waits.

Its flicking tongue collects smells for a special smelling organ in the roof of its mouth. Pits on its face sense the warmth of an animal, so it can strike even in the dark. It bites with long, hollow fangs that inject venom, then follows the scent trail to find its meal and swallows it whole. An adult may eat only every two or three weeks.

The diet is mainly small mammals and birds, with occasional reptiles and amphibians (Animal Diversity Web). Rattlesnakes typically hunt by ambush, often at dusk: the forked tongue carries odor particles to the vomeronasal (Jacobson's) organ, and the facial pits detect infrared radiation, which San Diego Zoo Wildlife Alliance explains is processed in the same brain region as vision, so the snake effectively sees a heat image.

Venom from glands above the upper jaw is delivered through hollow fangs, and the snake controls how much it releases. After the strike it relies on scent to trail the prey, which is swallowed whole. Wild rattlesnakes eat every two to three weeks on average, and in dry places much of their water comes from prey.

Rattlesnakes are shy.

They hide or slip away if they can. They rattle to warn others to stay back. If you ever see a snake, stay far away and tell a grown-up.

Rattlesnakes do not chase people. When they sense danger, they first try to hide or escape. If they cannot, they coil up, lift the front of the body into an S shape, hold the tail up and rattle, which is the warning you see in the photo.

Texas wildlife experts say: if you see a rattlesnake, stand still until you know where it is, let it move away, and back off slowly. Never touch or tease a snake. Hawks, eagles and roadrunners all hunt rattlesnakes, and kingsnakes can even eat them.

Rattlesnakes first try to escape or rely on camouflage; if threatened they hiss, rattle and enlarge the body, and the western diamondback's threat posture is a flattened spiral coil with the forebody raised in an S-curve and the tail lifted. Texas Parks and Wildlife stresses that snakes do not prey on people or chase them, that the danger comes when a snake is surprised or cornered, and that most bites result from people taking unnecessary risks with venomous snakes.

San Diego Zoo Wildlife Alliance notes that few snakebites are fatal to people but that any venomous bite needs immediate hospital care. Natural predators include hawks, eagles, roadrunners and wild turkeys (ADW), and kingsnakes are highly resistant to rattlesnake venom.

There are lots of western diamondbacks.

They help by eating mice and rats. Snakes are part of nature, so we leave them alone.

Western diamondbacks are common across a huge area, so they are listed as least concern, and their numbers seem stable.

Some local groups have been harmed by roads, by building on their habitat and by people killing them. Wildlife experts ask people not to kill snakes: they keep rodent numbers down, and a rattlesnake usually only wants to be left in peace.

The IUCN lists Crotalus atrox as Least Concern (assessed 2007, flagged as needing an update), with a stable trend and an adult population that certainly exceeds 100,000. No major threats are identified, although some populations have been badly reduced by habitat destruction, road traffic and direct killing, especially during organized "rattlesnake roundups."

Texas Parks and Wildlife asks people not to kill snakes, even venomous ones, because they serve a valuable function in the environment; rattlesnakes help control rodents.