Overview

Eastern Diamondback Rattlesnakes (Crotalus adamanteus) are the largest rattlesnakes in the world, possibly measuring up to 243.84 cm in total length and 7 kg in weight. Adults are typically 100-150 cm and weigh 1.8-2.3 kg. This species is sexually dimorphic in size with males attaining greater lengths than females. Juveniles range from 30-46 cm at birth. Eastern Diamondback Rattlesnakes are easily identified by the pattern of dark brown to black diamonds, bordered with a cream to yellow line, along the back. They have broad heads, strongly keeled scales and the tail ends with a prominent rattle. The rattle is composed of loosely articulated segments of keratin that make a buzzing sound when shook and a new segment is added to the rattle each time a snake sheds its skin. Eastern Diamondback Rattlesnakes are restricted to the Coastal Plain of the southeastern United States. They historically ranged from extreme eastern Louisiana to southeastern North Carolina and south through all of Florida. Although they can still be locally common these rattlesnakes are experiencing significant population declines throughout their range. Currently they are now nearly extirpated from Louisiana, considered endangered in North Carolina and rare in Mississippi, Alabama and South Carolina. The presettlement habitat of Eastern Diamondback Rattlesnakes was likely fire maintained, open canopy, pine habitats, such as longleaf pine/wiregrass uplands and sandhills, pine flatwoods, and pine-oak scrub. However, these habitats have declined significantly due to the spread of agriculture, urbanization, and the removal of fire from the landscape.

Habitat

Eastern Diamondback Rattlesnakes are often found in association with Gopher Tortoises (Gopherus polyphemus), and their burrows are an important refuge for diamondbacks, especially in the northern parts of their range. Diamondbacks will use these burrows, and other shelters, such as armadillo (Dasypus novemcinctus) burrows, stump holes and the root systems of windfallen trees as a refuge from extreme temperatures, predators and as parturition (birthing) sites. Home range size in Eastern Diamondback Rattlesnakes can vary greatly between snakes and throughout their range. Males often have larger home ranges (up to 240 ha) than females (up to 80 ha), likely because of their search for mates. If two males are attempting to mate the same female, they may engage in a ritualized combat, in which they intertwine their bodies and attempt to pin the other to the ground, with the winner gaining breeding rights. After mating, the female stores the sperm through the winter, and the ova are fertilized the following spring. Females only reproduce every two to four years. Eastern Diamondback Rattlesnakes are ambush predators, using their cryptic coloration to remain concealed. Eastern Diamondback Rattlesnakes feed on a wide variety of endothermic (warm-blooded) prey, although their diet consists mainly of small mammals such as rabbits (Sylvilagus spp.), rats (Sigmodon hispidus, Neotoma floridana), squirrels (Sciurus spp.), and mice (Peromyscus spp.).

For more information, download the Eastern Diamondback Rattlesnake Fact Sheet