Eastern Diamondback Rattlesnake

The biggest venomous snake in North America is the Eastern Diamondback Rattlesnake.

These snakes are big, heavy, and long. For such a big snake, they’re hard to spot in the wild because their color and markings are superb camouflage. Their yellow-bordered diamond-shaped markings make them the most brightly colored of all the diamondback rattlesnakes while still keeping them hidden in the underbrush. This snake has a fearsome reputation, and you wouldn’t be wrong for being cautious around it. They are big and bad and don’t back off when you corner them.

3 Amazing Facts About Eastern Diamondback Rattlesnakes

• Eastern diamondback rattlesnakes live for 15-20 years and more in captivity, but biologists believe it’s closer to 10 years in the wild.
• Females mate every couple of years and carry the eggs in their bodies while developing for half a year before giving birth to baby snakes.
• This snake raises its body off the ground in an S-shape when it feels threatened. This is a sign that it’s ready to strike.

Where to Find Them

This species inhabits the coastal regions of Louisiana, Mississippi, Alabama, Georgia, North Carolina, South Carolina, and most of Florida, extending into the Keys. They prefer longleaf pine forests, pine Flatwoods, turkey oak hammocks, and palmetto stands. This terrestrial snake doesn’t climb much (and they’re not very good at it), but they can swim.

Eastern diamondback rattlesnakes often hide underground in the holes of rabbits and squirrels and come out during the evening hours to hunt when they need some rest.

This species is both an active hunter and an ambush predator. When it’s waiting for prey, it can stay in the same place for nearly a week before moving on or capturing something.

Scientific Name

This snake goes by Crotalus adamanteus as its scientific name; it roughly translates as “hard as steel rattle,” and it fits. Eastern diamondback rattlesnakes are more likely to bite than their western diamondback rattlesnake cousins; and are inclined to stand their ground instead of escaping.

They’re part of the Crotalinae subfamily of Vipers with their cousins, the cottonmouth snake and bushmaster snake. This subfamily holds the pitviper genera and is endemic to the Americas. There are approximately 30 rattlesnake species, all of which are venomous.

Types

Three rattlesnake species are considered Diamondbacks; they get their name from the diamond-shaped markings they exhibit. These snakes inhabit many areas of the south and the southwestern United States and northern Mexico.

• Western Diamondback Rattlesnake (Crotalus atrox) inhabits the desert southwest United States and northern Mexico.
• Eastern Diamondback Rattlesnake (Crotalus adamanteus) occurs in the southeast United States from North Carolina, south to Florida, and east to Mississippi and possibly Louisiana.
• Red Diamondback Rattlesnake (Crotalus ruber) has three recognized subspecies, Cedros Island red diamond rattlesnake (C. r. exsul), San Lucan red diamond rattlesnake (C. r. lucasensis), and the red diamond rattlesnake (C. r. ruber).

Population and Conservation Status

The IUCN Redlist lists the eastern diamondback rattlesnake as Least Concern; however, they note that the snake’s population is declining. However, their current population is approximately 3% of their historic numbers. They are protected in North Carolina, and the US Fish & Wildlife Services is considering adding them to the Endangered Species List.

Eastern diamondback rattlesnakes give birth in late summer and early fall, about six months after mating, to between eight and 29 neonates that are fully capable of defending and feeding themselves. Newborn snakes stay with their mother for 10 – 20 days; or until the neonates have gone through their first shed.

Appearance and Description

The eastern diamondback is the biggest rattlesnake in the world. It can reach 8 feet long, and the longest one on record was 99 inches, that’s 8 feet, 3 inches long. They have a large, spade-shaped head that is significantly wider than the neck, elliptical (cat-eye) pupils, and heat-sensing pits between their nostrils and eyes. This species has a dark stripe flanked by lighter stripes extending diagonally from just below the eyes to the bottom lip.

Eastern diamondback rattlesnakes are well-named because they have brown or black diamond-shaped markings down the length of their backs. These have yellowish borders that stand out from their base color of brown to light brown. Their markings sometimes fade towards the tail, and they typically have black and brown bands on their tail; however, in some individuals, the tail may be so dark that it’s hard to see the bands. Juveniles of the species have brighter, more vivid colors than mature snakes. The diamonds aren’t always “perfect,” Sometimes, they’re more trapezoid-shaped, but it’s easy to identify these snakes.

True to their name, their tails end in a rattle made of nested scales. Some say that you can tell a rattlesnake’s age by the number of links in its rattle; however, this is false. The rattle segments are brittle and break easily; they also add a new rattle every time they shed, several times per year.

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Venom: How Dangerous are They?

Eastern rattlesnake venom is full of hemotoxins, meaning their venom attacks the blood. However, it is also chock full of numerous other toxins attacking the cells, lungs, and heart. About one in 3 bites from one of these snakes is a dry bite, where they don’t inject venom.

Their venom-delivery system is highly effective; they have two hinged fangs attached to venom glands. As a result, Eastern diamondback rattlesnakes inject a large quantity of venom into their victims, sometimes as much as 400mg. A snakebite victim needs immediate medical treatment because about 10-20% of untreated bites cause death.

Researchers studied eastern diamondback rattlesnake venom to map the genetic profile of the toxins. As a result, they were able to double the number of toxins profiled in this species’ venom.

History and Evolution

Taking a look at the Eastern Diamondback’s evolution, you have to look at the pit viper’s evolution in general which evolved in the Miocene Era. Molecular phylogenies date Viperidae back further to the early Eocene Era around 56-48 million years ago. They originated in Africa, Asia, and Europe and later spread into North, Central, and South America.

Researchers believe there was an ancestral snake to modern rattlesnakes which existed around 22 million years ago. It had highly toxic venom composed of genes for toxins that could damage muscles, attack the nervous system, and poison the blood of its victims. Rattlesnakes came on the scene 12-14 million years ago but somehow shed certain neurotoxin genes, so that their venom became more specialized. For example, the venom of an Eastern or Western Diamondback rattlesnake damages muscles and blood vessels in its prey. On the other hand, the venom of the Mojave rattlesnake attacks the blood and nervous system.

When it comes to the introduction of that well-known rattlesnake rattle, it could have been adapted as a way to warn enemies. It perhaps could have been from excess shredded skin that produce noise as the snake moved and shook it.

Behavior and Humans

We know rattlesnakes by their sound: the warning rattle. However, they don’t always rattle. There are times that they try to hide rather than call attention to themselves by rattling their tails. Many rattlesnake species don’t always rattle a warning; they stay quiet and hope you’ll go away. Eastern diamondback rattlesnakes also do this; they use their best reptilian judgment to decide whether or not to rattle.

These snakes thrive in the underbrush, where most of their prey animals also live; and can spend up to a week without moving. Most bites occur on the extremities (the hands, arms, feet, and legs) because someone either got too close and stepped on it or picked it up. Eastern diamondback rattlesnakes hide in palmetto palms and longleaf pine forests, where their markings and colors help them stay hidden.

Similar Animals

• Southern pacific rattlesnake
• Timber rattlesnake
• Pygmy rattlesnake (Massasauga)