GENERAL INFORMATION

Rattlesnakes are members of the Pit Viper family, which includes all the venomous snakes found in North America with the exception of the Coral Snake. They are best known for the presence of a "rattle" on the end of the tail. The rattle is actually a series of loosely attached, interlocking hollow segments composed of keratin. When a rattlesnake is frightened or disturbed, it vibrates the tail tip which results in the characteristic buzzing or rattling sound.

DESCRIPTION

The Timber Rattlesnake is a heavy-bodied snake averaging around 3 feet in length With occasional individuals approaching 5 or 6 feet. They vary greatly in overall coloration depending on the region in which they occur. Specimens from the lowlands of eastern North Carolina are typically very light in coloration, often a pinkish-tan with dark black or brown crossbands. These eastern Rattlesnakes were formerly classified as a separate species known as the Canebrake Rattlesnake, but are now considered to be just another color phase of the Timber Rattlesnake. Timber Rattlesnakes from the mountain regions of Western North Carolina occur primarily in two varieties, a yellow phase and a black phase. The yellow phase tends to be more common in most areas. Yellow phase Timber Rattlesnakes have a background coloration of yellow or tan with brown or black crossbands. Black phase Timber Rattlesnakes are sometimes almost solid black in coloration but usually sport the same pattern as the yellow phase with the yellow or brown being replaced by much darker pigments. Contrary to popular opinion, the sex of a Timber Rattlesnake cannot be determined by its color phase. Because of its many different color varieties, people often mistake the Timber Rattlesnake for other rattlesnake species, particularly the Eastern Diamondback Rattlesnake. However the Timber Rattlesnake is the only species of rattlesnake found in Western North Carolina. Like other pit vipers, the head of the Timber Rattlesnake is very broad in comparison to the neck. The pupils of the eyes are elliptical in shape (in bright light only) and there are heat-sensitive pits, one on either side of the face, between the eye and the nostril. Rattle segments on the tail periodically break off and. individual rattlesnakes will vary in the number of rattle segments present. A new segment is added to the rattle each time the snake sheds its skin, which may occur several times a year.

HABITS AND HABITATS

The Timber Rattlesnake occupies a variety of habitats depending on the time of year. Summer ranges include heavily forested areas, rocky hillsides, and fields bordered by forests. In early fall, Timber Rattlesnakes begin moving towards their winter hibernation dens which are typically rocky outcrops with deep crevices leading well below the frost line. Rattlesnakes often congregate near the den opening, sunning on the warm rocks by day and then crawling inside for protection as the temperature falls at night. Eventually cold temperatures cause them to remain underground in a dormant state, hibernating until the following spring. By late May and early June, Timber Rattlesnakes have left the dens, eventually repopulating their summer ranges. Timber Rattlesnakes are primarily nocturnal, but may be encountered by day as well. They feed on a variety of small mammals, primarily rodents such as rats, mice, chipmunks, and squirrels. Other small animals such as birds are also eaten occasionally. Rattlesnakes may wait quietly in a likely spot and ambush their prey when it happens along or they may actively hunt their prey by investigating underground burrows, crevices, and other similar locations. Their heat-sensitive pits help them to pinpoint warm-blooded prey even in the dark when their vision may be somewhat limited. Tests have shown that rattlesnakes can accurately strike at warm objects even if deprived of their sight. They kill their prey by injecting venom, a modified and highly specialized form of saliva, from glands located deep in the muscles of the upper jaw. The venom is conducted through a pair of modified teeth in the front of the upper jaw, known as fangs. Prey animals seldom run farther than a few yards after being bitten by the rattlesnake. Like other snakes, the forked tongue of the Timber Rattlesnake is used for smelling. It trails the stricken animal with its sensitive tongue to wherever the prey has fallen. Interestingly enough, if the snake strikes a bird, it does not let go, instinctively knowing that a bird will fly away, not leaving a scent trail upon the ground that the snake could follow. Then, usually beginning with the head, the Timber Rattlesnake swallows its prey whole. Days or weeks may pass before the Timber Rattlesnake has an opportunity to feed again.Timber rattlesnakes bear live young during late summer or early fall. Litters range from around five to nineteen young which are totally on their own from birth, receiving no care from the female.

HISTORY

Although still common in some locations, the Timber Rattlesnake is rapidly declining throughout much of its range, primarily due to habitat destruction and intense persecution by man. Rattlesnake dens are often dynamited and individual rattlesnakes encountered by humans are almost always killed. Overcollecting of rattlesnakes has also become a major cause of their decline. In some states, the Timber Rattlesnake is now protected by law. Although most people believe that rattlesnakes are quite aggressive animals, the opposite is true. When encountered, most Timber Rattlesnakes will lie quietly, relying on their concealing coloration to protect them from a potential enemy. It is normally only in self-defense, when disturbed or stepped upon, that the Timber Rattlesnake will rattle its tail and strike. Although the Timber Rattlesnake is venomous, very few human bites are recorded and fatalities from bites are extremely rare. These beneficial snakes occupy important niche in our forests and if encountered, would rather be left undisturbed. MEET

OUR TIMBER RATTLESNAKES

The Nature Center has two Timber Rattlesnakes currently on display, a typical yellow phase specimen and a typical black phase. These rattlesnakes are both long-term captives and have lived at the Nature Center for several years. They were both originally wild caught in the Western North Carolina area and are now between 4 l/2 to 5 feet in length. They are each fed 2 to 3 pre-killed (to prevent injury to the snakes) rats once every 10 days to 2 weeks. Being cold-blooded, their metabolism is much slower than warm-blooded animals and therefore don't have to be fed as often. Timber rattlesnakes normally have a long lifespan in comparison to many other snake species. The record longevity in captivity is 29 years.

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©2002 WNC Nature Center