Eastern Diamondback Rattlesnake
The Eastern diamondback rattlesnake (Crotalus adamanteus) is a highly venomous pit viper species found throughout the southeastern United States. It's the largest of the 32 species of rattlesnakes currently recognized and is the heaviest but not the longest venomous snake found in the Americas.
This snake was featured prominently in the American Revolution, specifically as a symbol in the Gadsden flag, which many consider being the first flag of the United States of America.
The eastern diamondback rattlesnakes are found in the Lower Coastal Plains of the Southeast, ranging from the southern North Carolina to the eastern Louisiana, and are also found in Florida and southern Georgia.
These venomous snakes usually inhabit dry sandy areas, pinewoods, palmetto or wiregrass flatwoods and also hardwood hammocks, coastal dune habitats or even wet prairie habitats during dry periods.
Although they are very capable swimmers, that can travel through saltwater to and from barrier islands along the Georgia coast and in the Florida Keys, sometimes miles from land. They will usually avoid wet habitats but sometimes can be found along the edges of swampy areas.
The eastern diamondback rattlesnake frequently takes shelter in gopher and tortoise burrows, emerging in the early morning or afternoon to bask and hunt.
In many parts of its range, they rely heavily on gopher tortoise (Gopherus polyphemus) burrows to brumate during the winter months.
Like most rattlesnake species, eastern diamondbacks are almost exclusively terrestrial and not very fond of climbing.
However, they have on several occasions been reported in bushes and trees, presumably hunting for prey, even the larger eastern diamondback rattlesnakes have been spotted as high as 10 meters above the ground.
The individual temperament varies quite a lot, with some specimens starting to rattle at a distance of 20 to 30 feet (6–9 m) while others allow a close approach and still remain silent, their rattle is well developed and can be heard from relatively far away.
These are large and heavy-bodied snakes, with a large, broad head very distinct from the neck, with 2 light lines on their face.
The background color is brownish, yellowish, tan or even silvery gray to dark black. A row of namesake diamond shaped markings with brown centers outlined in yellow, cream or white runs down its back. At the end of the tail the diamonds start fading out or break into bands, they have keeled scales.
Their upper body is covered with lightly keeled scales and have only a single row of scutes on the ventral surface. Adult eastern diamondback rattlesnakes usually measure between 33 and 72 inches (84-183 cm) long, but the largest eastern diamondback snake ever recorded was 96 inches (244 cm).
The average weight of an Eastern Diamondback Rattlesnake is 5 to 10 pounds, with male snakes being both larger and heavier than females. The species is the largest venomous snake in North America and the largest rattlesnake in the world.
They also have very long fangs, on average a 8 ft snake could have fangs with a length of over 1 inch (25 mm). When the snake feels threatened, it will raise the anterior half of the body off the ground in an S-shaped coil, and it can strike at a distance of at least a 1/3 of their total body length.
Many times eastern diamondbacks will stand their ground and may strike repeatedly, but like most snake species if given the opportunity, they will usually retreat towards shelter.
The species was first described in 1799 by Palisot de Beauvois, as Crotalus adamanteus, later in 1896 Boulenger classified the snake as Crotalus durissus, however, this was not widely accepted.
Today the Eastern Diamondback Rattlesnake scientific name remains Crotalus adamanteus, with the latin "Crotalus" meaning rattle tail and "adamanteus" referring to the diamond-like pattern. There are no subspecies are currently recognized.
The Eastern Diamondback has an extremely potent snake venom, and delivers it in great quantities, with an average yield of 410 mg (dried venom) per bite. The estimated average human lethal dose is around 100–150 mg. If left untreated the bite mortality rate is between 10% and 20%, but less than 1% when treated.
Their venom may contain as many as 95 different proteins and enzymes, including neurotoxins, myotoxins, procoagulants, cardiotoxins, hemorrhagins, nephrotoxins, necrotoxins, platelet aggregation inhibitors and many other compounds. A bite will cause intense internal pain, bleeding from the bite site, hypotension and weak pulse and swelling.
Diet / Feeding
The eastern diamondback can both lie in ambush or forage actively hunting small mammals, mainly rabbits, mice, and rats, but their diet also includes birds or even large insects. These snakes are very beneficial to humans because many of the animals they kill and eat are considered pests.
When hunting they strike and immediately release the unfortunate prey, after which the snake will follow the scent trail left by the animal using the forked tongue and the Jacobson's organ located in the upper jaw.
Rattlesnake species, including the eastern diamondback, are ovoviviparous, they produce eggs that are hatched inside the body. The female gives birth to live snakes usually between July and early October, to anywhere between 7 and 21 hatchlings at a time.
The gestation period lasts for 6 or 7 months and broods average about a dozen younglings. The hatchlings are between 12 and 14 inches (30–36 cm) in length and have a similar appearance to that of the adult eastern diamondback rattlesnake specimens.
The exception is having only a small "button", (the 1st segment of their future rattle) instead of a full sized rattle on the tip of their tails. The young snakes don't stay with the mother for long before they set off on their own, so their mortality rate is very high.
But they are still capable of delivering a deadly bite. Eastern diamondback rattlesnakes grow very slowly and take several years to reach maturity, beside that adult female snakes only reproduce every 2 or 3 years.
Conservation / Threats
The eastern diamondback is classified as Least Concern on the IUCN Red List, a species is listed as such due to their wide distribution and presumed large population. But because of their indiscriminate killing, commercial hunting for skins, highway mortality and widespread loss of habitat to agricultural, urban development and forestry practices, its numbers are decreasing throughout their historical range.
So it's currently under review for being added to the Endangered Species List by the United States Fish and Wildlife Service due to the decline in population numbers, that account only for about 3% of their historical population.
In North Carolina, the species is considered endangered or even extirpated, and is protected by state law, the eastern diamondback rattlesnake was last observed in Louisiana in 1995, so it's probably extirpated in that state too.
Did You Know?
One bite of the australian inland taipan contains enough venom to kill up to 100 full grown men.