Sidewinder

Sidewinders eat lizards and mice.

Sometimes a big one eats a bird.

Sidewinders eat mostly lizards and small mammals such as mice, and big sidewinders sometimes eat birds. Lizards make up more than half of what they eat.

A sidewinder often waits just under the sand for an animal to come close. In late spring and summer, when it hunts at night, it eats more mammals; in early spring and fall it catches more lizards that are out in the day. After eating, it may stay still for 5 to 10 days.

ADW: over 50% of the diet is lizards (e.g. zebra-tailed lizards, western whiptails, Colorado Desert fringe-toed lizards) and over 40% mammals (e.g. pocket mice, house mice, Botta's pocket gopher); large sidewinders also take birds. More mammals are eaten when the snakes are nocturnal in late spring and summer, more diurnal lizards in early spring and fall. Snakes may stay inactive for 5 to 10 days after feeding. The NPS lists lizards, small mammals and birds, and describes sidewinders waiting for prey while buried in the sand; the North Carolina Zoo notes that they often sit just under the sand to ambush prey.

A sidewinder smells with its tongue.

It can feel the warmth of animals nearby.

Like other rattlesnakes, a sidewinder has a pit on each side of its head that senses heat, which helps it find warm-bodied prey. It flicks its tongue to pick up smells, and a special smell organ, the vomeronasal organ, reads them. It relies on smell more than sight.

Sidewinders can even detect a substance in the skin of kingsnakes, a snake that eats them, and stay away.

ADW: facial pits detect infrared radiation and are used to find prey; tongue flicking delivers chemical cues to the vomeronasal organ, which sidewinders rely on more than sight to detect prey; they have been shown to detect substances in kingsnake (Lampropeltis) skin and so avoid them. Males use touch in mate searching, courtship and catching prey, and all three ways of moving (sidewinding, rectilinear motion and lateral undulation) need the snake to feel the ground.

A sidewinder moves sideways over the sand.

It leaves tracks shaped like the letter J.

A sidewinder moves by throwing its body sideways in loops. This lets it move quickly across loose sand, and because only a little of its body touches the hot sand at a time, it helps it keep cool. Its tracks look like a row of J shapes.

Sidewinders are most active at dawn and dusk, and at night in hot weather. In the heat of the day they hide in rodent burrows, or wiggle down into the sand until they are almost buried. In winter they rest in the burrows of rodents or desert tortoises.

The NPS describes sidewinding as fast travel over sand that also keeps the snake cool by limiting how long any part of the body touches hot sand, and the J-shaped tracks that may end in a small depression where a snake has 'cratered': shifting side to side until almost buried. Sidewinders are crepuscular, also nocturnal in warm periods (NPS); by day they shelter in burrows or under bushes, or stay partly buried in sand until it gets too hot; they hibernate in rodent or tortoise burrows and rarely climb into vegetation (IUCN). When threatened, a sidewinder shakes its rattle (ADW).

There are lots of sidewinders.

Some live in national parks.

The sidewinder is listed as least concern. It lives across a wide area, there are probably more than 100,000 adults, and its numbers are probably fairly steady. No major threats to it are known, and sidewinders are found in a number of protected places, such as national parks.

If you see one in the wild, enjoy it from far away and leave it alone.

Frost, Hammerson and Gadsden assessed Crotalus cerastes as Least Concern (Global; assessed 1 March 2007, published 2007; needs updating): wide distribution, many occurrences, adult population unknown but presumably over 100,000, locally common in suitable habitat, extent, occupancy, subpopulations and population probably relatively stable; no major threats known; several to many occurrences in protected areas (IUCN). Predators include California kingsnakes, coyotes and red-tailed hawks (ADW).