SCIENTIFIC NAME:
Crotalus adamanteus
STATUS:
Uncommon to rare and possibly threatened. Alabama's largest venomous snake. Infrequently encountered where formerly common, and now absent from many areas of historic occurence. HIGH CONSERVATION CONCERN.
DESCRIPTION:
The eastern diamondback rattlesnake (Crotalus adamanteus) is the largest species of rattlesnake in the world. It is a heavy-bodied snake that can reach lengths close to seven feet, although the average adult is four to five feet. The tail is short and stout with a rattle or button at the end. The rattle is composed of hollow, interlocking segments that click against each other when the tail vibrates. The topside of the snake contains the characteristic yellow diamond shapes surrounding black and brown centers. The belly is generally yellowish to white. The large and distinctive head is marked with a dark band extending obliquely from each eye to the lips. The band is bordered on each side by a light streak. A heat sensitive “pit” is located on each side of the head between the eye and nostril. The upper jaw contains movable recurved fangs. When encountered, the diamondback will often remain motionless until a threat is perceived or the snake is actually touched. A defensive posture is a coiled position with rattle erect, buzzing, and head near center of the coil. The act of striking can extend up to two-thirds the length of the snake. Thirty-six of 39 species of rattlesnake are in the genus Crotalus and range from Canada to Argentina. Two species, C. adamenteus and C. horridus (Timber rattlesnake) occur in Alabama.
DISTRIBUTION:
Crotalus adamanteus ranges from coastal plain regions of southeastern North Carolina to eastern Louisiana, including all of Florida. The eastern diamondback rattlesnake is locally common in suitable habitat regions of extreme south Alabama in the lower coastal plains and the adjacent band of red hills to the north.
HABITAT:
Favored habitats for the diamondback include dry pine flatwoods and longleaf pine-turkey oak hills. It is able to survive in altered habitats such as overgrown fields and abandoned farms. Although the eastern diamondback rattlesnake is usually associated with sandhill communities, it will venture into swampy and marshy habitats. Overwinters in stump holes and gopher tortoise burrows, where it is vulnerable to "gassing" by snake hunters.
FEEDING HABITS:
The eastern diamondback rattlesnake feeds primarily on small mammals such as rabbits, mice, and rats. Other food items include squirrels and ground-dwelling birds. The typical hunting strategy is waiting motionless in a coiled position to ambush prey that comes within striking distance. It can spend as much as a week coiled in the same position. In a successful hunting event, the venom is pumped through the fangs into the prey to kill and digest the animal. The venom of the eastern diamondback rattlesnake attacks blood, tissue, and the nervous system.
LIFE HISTORY AND ECOLOGY:
During late summer and early fall, the female will seek a sheltered location and give birth to a litter ranging from eight to 15 live young. A home range for an adult male can be as large as 500 acres. The diamondback will often use gopher tortoise burrows for refuge, especially during cold weather. It will also seek shelter in armadillo burrows, stump holes, root channels, under palmetto thickets, and in other underground cavities. An eastern diamondback rattlesnake may live up to 20 years, but the typical lifespan in the wild would be about 10 years.
Conservation Advisory Board Bans ‘Gassing’ of Wildlife Burrows:
It is “illegal to introduce gasoline or any other noxious chemical or gaseous substance into wildlife burrows, dens or retreats.”
This specifically targets the practice of “gassing” gopher tortoise burrows to flush out and capture eastern diamondback rattlesnakes that has been a common practice used by some snake hunters. Scientific studies have shown that the introduction of gas into a gopher tortoise burrow results in death of the wildlife in many cases, sometimes two to three months later. This technique is not an ecologically sound practice and has been prohibited in Florida and Georgia for a number of years.
The gopher tortoise is a state-protected species and is currently federally-listed as a threatened species in three Alabama counties: Mobile, Washington, and Choctaw counties. It is considered a “keystone” species, with over 300 wildlife species being documented using its burrow as refuge and dens, including species of concern such as the federally listed Eastern Indigo snake and black pine snake.
REFERENCES:
Baily, M. and K. Studenroth. Fall 2001. The Eastern Diamondback Rattlesnake. Alabama Wildlife Magazine.
Mount, R.. 1975. The Reptiles & Amphibians of Alabama. Auburn Printing Co., Auburn, AL. 347 pp.
Author:
Steve Barnett, Alabama Division of WIldlife and Freswater Fisheries
