Do Roadrunners Eat Rattlesnakes? Desert Diet Facts

What roadrunners really eat

The greater roadrunner is an opportunistic predator of the desert Southwest and Mexico. Studies of stomach contents and observations of hunting birds show a broad diet:

• Insects and other invertebrates: grasshoppers, crickets, beetles, caterpillars, cicadas, centipedes and scorpions, and spiders including tarantulas and black widows.
• Lizards: whiptails, spiny lizards, side-blotched lizards, horned lizards and many others.
• Snakes: garter snakes, whipsnakes, young rattlesnakes and other small species.
• Mammals: mice, kangaroo rats, young ground squirrels and occasionally bats.
• Birds: small songbirds, hummingbirds at feeders, and eggs and nestlings taken from nests.
• Plant food and carrion: a little fruit and seed, especially in winter, and occasionally dead animals such as roadkill.

The exact mix changes with the seasons. In spring and summer, when insects and lizards are abundant, they make up most meals; in winter, when reptiles are inactive, roadrunners eat more rodents, birds and plant food. By number, insects are usually the most common item, but reptiles and small mammals supply a large share of the food by weight. Moisture-rich prey also provides much of the water a roadrunner needs in a dry habitat.

How a roadrunner tackles a rattlesnake

When a roadrunner meets a snake small enough to handle, it uses speed and timing rather than strength. The bird circles and feints, often with its wings partly spread, keeping just out of range of the snake’s strike. It then darts in and grabs the snake near the head with its long, hooked bill.

Once it has a grip, the roadrunner lifts the snake and beats it repeatedly against the ground or a rock until it stops moving. It then swallows the snake head first. The Cornell Lab of Ornithology notes that roadrunners sometimes team up: one bird distracts the snake by jumping and flapping while the other sneaks in to pin its head.

The rattlesnakes taken are small or young individuals. A large adult western diamondback can be more than a meter long and heavy, far too much for a bird that weighs well under 600 g (1.3 lb). The idea of roadrunners routinely fighting full-sized rattlesnakes owes more to folklore and the bird’s old nickname, “snake killer”, than to everyday reality.

Swallowing long prey in stages

A roadrunner has no teeth and swallows its prey whole. When a snake or lizard is too long to fit inside at once, the bird swallows as much as it can and walks around with the tail end hanging out of its bill. As the front part is digested, it gradually swallows the rest. It may carry prey like this for some time while it continues its day.

Horned lizards, with their sharp spines, are a special case. Roadrunners are careful to swallow them head first, so the horns point away from the bird’s throat and vital organs.

Is a roadrunner immune to venom?

There is no good scientific evidence that roadrunners are immune to rattlesnake venom. Their protection comes from speed, sharp reflexes and technique: keeping out of reach, striking the head first and disabling the snake quickly.

Roadrunners also eat other venomous prey. Scorpions, including the Arizona bark scorpion, as well as tarantulas and black widow spiders, appear in their diet, and the birds seem to handle them without harm. They usually beat or crush such prey before swallowing it, which may reduce the risk of stings and bites.

How roadrunners hunt

Roadrunners hunt by walking, trotting and running through open scrub, stopping often to watch and listen. They catch most prey with a quick dash and a stab of the bill. Other techniques include:

• Ambush: waiting in shade near a bird feeder, water source or busy insect patch, then dashing out.
• Leaping: jumping straight up to snatch flying insects or small birds.
• Flushing: walking through vegetation to disturb insects and lizards.
• Nest raiding: climbing into shrubs to take eggs and chicks.

Like other desert animals, roadrunners hunt most actively in the cooler hours. In summer they are busiest from sunrise to mid-morning and again in the late afternoon.

Roadrunners and people’s gardens

In suburbs of Arizona, New Mexico, Texas and southern California, roadrunners hunt lizards in rock gardens and sometimes catch songbirds and hummingbirds near feeders. This is natural predator behavior. Roadrunners are wild birds protected under the Migratory Bird Treaty Act and should be watched from a distance, not fed.

If you live or hike in this region, our guide to snakes in Arizona explains which rattlesnakes share the roadrunner’s habitat and how to stay safe around them. If anyone is bitten by a snake, seek emergency medical help immediately by calling 911.