Crotalus adamanteusEastern Diamondback Rattlesnake

Last updated:

Geographic Range

The Eastern Diamondback lives in the coastal lowlands, ranging from southeast North Carolina to eastern Louisiana, and throughout Florida, including the Florida Keys. (Conant and Collins 1998)

Habitat

The Eastern Diamondback resides in the palmetto flatwoods and dry pinelands of the South. It generally avoids marshes and swamps, but on occasion will live near the borders of wetlands. Occasionally it may venture into salt water, swimming to the outlying Keys off the Florida coast. (Conant and Collins 1998, Ashton and Ashton 1985)

Physical Description

The Eastern diamondback is one of the largest North American snakes, with a record length of 8 feet. However, they are usually 33 to 72 inches in length. The snake has a large head and a bulky body. It has a row of large dark diamonds with brown centers and cream borders down its back. The ground color of the body ranges from olive, to brown, to almost black. The tail is usually a different shade, brownish or gray, and banded with dark rings. At the end of the tail is a well-developed rattle. The head has a light bordered dark stripe running diagonally through the eye. The pupil is vertical (catlike). There is a large pit between the nostril and eye. The young are similar to the adults in color pattern. The tip of the tail of a newborn diamondback ends in a button, which is the first segment of the future rattle. Male and female rattlesnakes look alike. (Conant and Collins 1998, Ashton and Ashton 1985)

Reproduction

Eastern Diamondbacks mate in the late summer and fall. The size of the brood ranges from 6 to 21 young. The gestation period is six to seven months. Young are born live, in retreats such as gopher tortoise burrows or hollow logs. At the time of birth, the baby snakes are 15 inches long. The snakes can live 20 years or more. (Georgia Wildlife Federation 1999)

Lifespan/Longevity

Behavior

Diamondbacks are primarily solitary animals. During the mating season, however, there is a male social dominance system. Males compete for females through combat sessions. The snakes rise up the front section of their bodies, and entwine each other. They try to throw one another to the ground by pushing with the body and the neck.

The diamondback is crepuscular, or most active in the evening or early morning. Most activity is at ground level, but on rare occasions the diamondback will climb a few feet off the ground into bushes in pursuit of prey. In regions with cold winters, the diamondback hibernates in mammal or gopher tortoise burrows, hollow logs or stumps, or among the roots of trees.

The individual dispositions of Eastern Diamondbacks vary. Some snakes will allow close approach without making a sound, whereas others will rattle from 20-30 feet away. Many diamondbacks stand their ground, but when hard pressed will back away. If provoked severely, the snake coils, rattles its tail, and raises its head into the striking position. If threatened further, the snake may bite.

Adult Eastern Diamondbacks do not have any natural enemies, however the young have many enemies such as hogs, carnivorous mammals (the gray fox), raptors (the red-tailed hawk), and other snakes (especially king snakes). (Ashton and Ashton 1985, King 1996, Georgia Wildlife Federation 1999)

Food Habits

The Eastern diamondback feeds primarily on small mammals, from mice to rabbits. It will also eat birds. Young diamondbacks feed primarily on rats and mice, while adults prefer larger prey like rabbits and squirrels. The snakes lie waiting for prey beside logs or near the roots of fallen trees. Diamondbacks locate their prey by odor, as well as by sensing the infrared waves (heat) given off by their warm-blooded prey. Once found, the prey is bitten. The prey is released after the strike, and is then allowed to crawl away and die. The snake will pursue the prey, eating it once it is dead. (Ashton and Ashton 1985, King 1996)

Economic Importance for Humans: Positive

This snake is extremely beneficial to man. It preys on rats, mice, rabbits, and other small mammals, many of which are pests to humans. (Ashton and Ashton 1985)

Economic Importance for Humans: Negative

none

Conservation Status

Though not endangered, the Eastern Diamondback is clearly in trouble. The snake is rapidly disappearing from many areas in which it formerly occupied. Suburban housing and agricultural development destroys vast areas of habitat for the rattlesnake. Most snakes are killed on sight when found by humans. 'Rattlesnake roundups' held annually in several states of the U.S. further decrease their numbers. Crotalus adamanteus is regulated in North Carolina, a permit is required to

collect it, and in Florida a permit is needed to possess all vcenomous snakes. (King 1996, Georgia Wildlife Federation 1999, Levell 1997)

Other Comments

The Eastern Diamondback is a large, impressive, and potentially dangerous snake. It can strike up to 2/3 its body length; a 6-foot specimen may strike 4 feet. The venom of the diamondback is potent. When severely bitten, the mortality rate for humans is nearly 40 percent. The symptoms of diamondback venom include pain, swelling, weakness, breathing difficulty, weak pulse, heart failure, shock, and sometimes convulsion. This is a snake that should be left alone and not molested. (Ashton and Ashton 1985)

Contributors

Erin Siebert (author), Michigan State University, James Harding (editor), Michigan State University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

native range

the area in which the animal is naturally found, the region in which it is endemic.

References

"Georgia Wildlife Federation. Eastern Diamondback Rattlesnake" (On-line). Accessed November 16, 1999 at http://www.gwf.org/library/wildlife/ani_diamon.htm.

Ashton, R., P. Ashton. 1985. Handbook of Reptiles and Amphibians of Florida. Miami, FL: Windward Publishing, inc..

Conant, R., J. Collins. 1998. A field Guide to Reptiles and Amphibians. NY: Houghton Mifflin Company.

King, W. "Florida Museum of Natural History" (On-line). Accessed November 16, 1999 at http://www.flmnh.ufl.edu/natsci/herpetology/fl-guide/venomsnk.htm.

Levell, J. 1997. A Field Guide to Reptiles and the Law. Serpent's Tale Books.