Rattlesnakes in The Rattlesnakes of Snake Bite: First Aid What San Diego County Parks San Diego County The primary purpose of the rattlesnake’s venomous bite is to assist the reptile in securing The Rattlesnake is an important natural • Colorado Desert Sidewinder its prey. After using its specialized senses to find You Should element in the population control of small (Crotalus cerastes laterorepens) its next meal, the rattlesnake injects its victim mammals. Nearly all of its diet consists of Found only in the desert, the sidewinder prefers with a fatal dose of venom. animals such as mice and rats. Because they are sandy flats and washes. Its colors are those of Know About so beneficial, rattlesnakes are fully protected the desert; a cream or light brown ground color, To prevent being bitten, the best advice is to leave within county parks. with a row of brown blotches down the middle snakes alone. Rattlesnakes If you encounter a rattlesnake while hiking, of the back. A hornlike projection over each eye Most bites occur when consider yourself lucky to have seen one of separates this rattlesnake from the others in our area. Length: 7 inches to 2.5 feet. someone is nature’s most interesting animals. If you see a trying to pick rattlesnake at a campsite or picnic area, please up a snake, inform the park rangers. They will do their best • Southwestern Speckled Rattlesnake (Crotalus mitchelli pyrrhus) tease it, or kill to relocate the snake. it. If snakes are Most often found in rocky foothill areas along the provided an coast or in the desert. This snake’s coloring looks escape route, Avoiding Rattlesnakes like decomposed granite; from cream or tan to they’ll escape rather than strike. But if someone is sometimes pink and yellowish, and usually with bitten, the following first aid is suggested. By being alert and knowing what they look like, indistinct bands of salt-and-pepper speckling. where they live, and when they are active, you Length: 8 inches to 3 feet. can usually avoid rattlesnake encounters. 1. Remain Calm

In parks, stay on trails. In other areas, if you • Red Diamond Rattlesnake 2. Immobilize the Bitten Extremity (Crotalus exsul) plan on hiking through brush, long pants and Do not apply a tourniquet or constriction boots are advisable. At night use a flashlight. A reddish-brown snake with the outline of band. Do not apply ice to the wound. In Southern California, snakes can be seen year cream-colored diamonds down its back. It usually Do not attempt to cut the wound or suck round. However, most rattlesnake sightings prefers areas of brush scattered rock – chaparral out the venom. occur in April, May, and June. along the coast, mesquite and cactus on desert slopes. It is not found high 3. Wash the Skin Red Diamond Rattlesnake in the mountains or on the desert flats. If soap and water are available, wash the skin Length: 9 inches to 5.5 feet. INFORMATION over the bite or use an antiseptic wipe. County of San Diego 4. Remove Jewelry and Tight Fitting Department of Parks and Recreation • Southern Pacific Rattlesnake 5500 Overland Avenue, Suite 410 (Crotalus viridis helleri) Clothing in Case of Swelling San Diego, CA 92123 Found virtually everywhere but the desert, this 5 Call for Help Reservations & Information: greenish-brown to black snake has brown to black . Toll Free ● (877)565-3600 blotches down its back. These blotches generally If possible, send someone to telephone 911. (858) 565-3600 Local ● have lighter edges. This snake is a subspecies of If alone, walk at a relaxed pace to the closest telephone and call 911. Get medical attention Visit us at www.sdparks.org the highly variable Western rattlesnake complex. as soon as possible. Printed on recycled paper 8/13 Length: 6 inches to 5 feet. The Tongue: The Rattle: A Vital Part of Smell Rattlesnake Fun Fact A Warning Sound By flicking its forked tongue, the rattlesnake Did you know that the rattles found on the tip of the tail When alarmed, the rattlesnake vibrates its tail constantly “tastes” the smell of the air. When the is dead skin that accumulates over time? in an effort to warn the intruder of its presence. snake pulls its tongue back in, it slides the tips Other snakes may do the same thing, but only into cavities on the roof of the mouth. the rattlesnake has a mechanical warning system These organs, called Jacobson’s Organs, contain – the rattle. branches of the olfactory nerve, the same nerve Behind each of these “pits” is a chamber, which Because of this sensitivity that leads to the nose. No wonder they have such is divided by a thin membrane. Contained in to light, the eye needs a keen sense of smell: when the snake flicks its this membrane is a densely packed group of protection during bright tongue into the air, picks up a scent, and then nerve endings. You have the same kind of nerve daylight. Its vertical pupil stimulates the olfactory nerve, in effect it is endings. They’re spread across your upper face protects it better than a extending its nose beyond its body. and allow you to sense warmth generated from a round pupil because it can source of heat, such as the sun. close almost completely. In pit vipers, though, these nerves are confined to the pit organs. These nerves are different from The Scales: yours in that they’re linked to the vision center A Keeled Mystery of the snake’s brain. You could almost call the rattlesnake a heat-seeking missile, guided by a If you encountered a snake highly specialized nervous system. and its tail was hidden from view, you might recognize it The Eyes: as a rattlesnake by its overall shape: large triangular head, Vision in Dim Light narrow neck and wide body. Colorado Desert Sidewinder Rattlesnake The rattlesnake’s pupil is a narrow vertical slit, The rattlesnake can also be Southern Pacific Rattlesnake like those in a cat’s eye. This type of pupil generally identified by looking only at its back. Each scale This rattle is composed of a number of hard, indicates an eye that is highly sensitive to vision in has a pronounced ridge, or keel, running down dry skin, much like your fingernails. The loose, The Pit Organs: dim light. That’s also true for a rattlesnake. its middle. articulation of these segments – not loose beads These keels give the rattlesnake within the segments, as some people believe – A Second Set of Eyes a rough, less “shiny” appearance results in the sound. When the snake vibrates its When a rattlesnake looks at a mouse in the than most snakes found in San tail, one segment strikes the other. The buzz that daylight, it senses both the reflected visual light Diego County. The function of results is a very effective warning. that a human would see and the infrared light these keels is uncertain, though given off by the mouse’s body heat. In total some scientists believe they A common belief is that the age of a snake can darkness, the rattlesnake can still find its prey promote concealment. be determined by counting the number by “seeing” only the mouse’s body heat. of segments in the rattle, one segment for By breaking up the light reflecting How does it do this? each year. Not true. One segment is added off the snake, the each time the snake sheds its skin, and most Rattlesnakes (and all other snakes in the pit viper keels may allow it to blend in group) have deep depressions, one on each side of with its dull surroundings. snakes shed several times per year. the face, between the eyes and nose. Southwestern Speckled Rattlesnake