Reptiles >> Squamata >> Viperidae >> Copperhead

The American Copperhead (Agkistrodon contortrix)

© 2019, Brandon Cornett | All rights reserved

The copperhead is a venomous pit viper found in the United States. The scientific name of this species is Agkistrodon contortrix. There are five supspecies of copperheads. This snake has excellent camouflage that allows it to hide among the leaves and dirt of the forest floor. While it is a venomous snake, the copperhead's bite is rarely fatal.

This is a venomous species. Do not attempt to handle.

Geographic range: This snake is widespread across the southern and southeastern parts of the United States. Interestingly, they are not found in the western half of the United States. The copperhead can be found along the Gulf Coast, across northern Florida, and up the eastern seaboard all the way to the southern portion of New York. Additionally, it occurs in most other states that are (A) east of the continental divide and (B) south of the Great Lakes.

Occurrence by state: Copperheads have been found in the following states, which are listed alphabetically: Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Texas, Ohio, Oklahoma, Maryland, Massachusetts, Mississippi, Missouri, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Tennessee, Virginia and West Virginia.

Clarification: American vs. Australian Copperhead

The term "copperhead" can refer to different snakes on two separate continents. There is both an American and an Australian copperhead. Aside from their names, and the fact that they are both venomous, these snakes have little in common. They look very different and occur in different families.

The American copperhead (Agkistrodon contortrix) is part of the Viperidae family of snakes, commonly known as vipers. This family includes rattlesnakes, moccasins, copperheads, and pitless vipers such as the Russell's viper. All snakes within this family are venomous.

The Australian copperhead (Austrelaps) is a member of the Elapidae family, which also includes cobras, mambas and kraits. All snakes within this family are venomous.

Most of this article pertains to the American species / subspecies. There is a special section at the end of this article dedicated to the Australian copperhead.

Scientific Classification of the American Copperhead

Order - Squamata

Family - Viperidae

Genus - Agkistrodon

Species - Agkistrodon contortrix

There are currently five recognized subspecies within this species: (1) A. c. contortrix, the southern copperhead; (2) A. c. laticinctus, the broad-banded or Texas copperhead; (3) A. c. mokasen, the northern copperhead; (4) A. c. phaeogaster, the Osage copperhead; and (5) A. c. pictigaster, the Trans-Pecos copperhead.

All of the subspecies are similar in appearance. They all have cross-bands that run the length of their bodies. In addition, they all have the broad, wedge-shaped head that is a hallmark of this species. They all have heat-sensing pits located on both sides of the head. But the coloration varies from one subspecies to the next. The coloration can also vary from one specimen to the next, within the same subspecies.

Physical Description

The copperhead is a fairly short but thick-bodied snake. Adults can grow to a length of 2 - 3 feet (61 - 91 cm). Some may grow longer, but such specimens are rare. The copperhead has a stout body that is common to an ambush hunter. The head is wide and shaped like a wedge, or a rounded triangle. Copperheads have vertical pupils and a slightly upturned snout. The head could be described as angular or chunky. The head tapers quickly into a narrow neck, which enhances the wedge-shaped appearance.

The snake's body is widest in the middle and tapers toward the tail. The copperhead has broad bands of a different color from the base color. Band coloration can vary among the different subspecies, and also among different populations within the same subspecies. The bands can be tan, brown, orange or grey. The base color is usually a paler tan or pinkish-tan. We have included several pictures of copperheads in this article to complement this description.

Pictures of Copperhead Snakes

A picture is worth a thousand words. In that spirit, we have rounded up some pictures of copperheads that serve to reinforce the information provided in this article.



Here's a copperhead picture that showcases the excellent camouflage of these snakes. Notice how it blends in with the leaves and soil of the forest floor. This picture makes me wonder how many copperheads I've walked past over the years, without even realizing it. The camouflage serves two purposes. It helps the snake get within striking distance of unsuspecting prey. It also helps it avoid becoming a meal for some other animal, such as a hawk, coyote or kingsnake.



Here's another picture that shows the tremendous blending characteristics of the copperhead.



This copperhead picture gives you a close look at one of the distinguishing features mentioned earlier, the heat-sensing pit. In this photo, you can clearly see the pit located just forward and slightly below the snake's eye. Copperheads have one pit on both sides of their head. They use these to detect their warm-blooded prey, even in total darkness.



Picture of a southern copperhead (Agkistrodon contortrix contortrix). This photo was taken in the Francis Marion National Forest in South Carolina.

Hunting and Eating: A Classic Ambush Predator

Some snakes are active hunters that seek out, and even chase down, their prey. Consider, for example, the green mamba of Africa (Dendroaspis angusticeps), a snake that glides among tree branches to capture birds and lizards. The copperhead is a different type of hunter. It is a classic ambush hunter.

Like many members of the Viperidae family, the copperhead frequently uses a "sit-and-wait" hunting strategy. The snake's thick body serves as a springboard, from which it can strike out quickly to capture its prey. It relies on its excellent camouflage for this purpose. You can see this camouflage in the pictures we have gathered below. The copperhead blends into the forest floor and waits for its prey to come within striking distance. This is a classic strategy used by the ambush hunters of the snake world.

Younger copperheads take this hunting technique to the next level. While the adult specimens rely on the classic "sit-and-wait" tactic of an ambush hunter, the juvenile specimens use a "bait-and-wait" strategy. A baby copperhead usually has a greenish-yellow area at the tip of the tail. It uses this specialized tail ending to lure in prey, by mimicking the color and movement of a worm or caterpillar. A frog or lizard will approach the "worm" to investigate a potential meal, not realizing that it's about to become the meal.

As the young snake matures, the colorful tail will fade away and take on a normal coloration that matches the rest of the body. It's nature's way of giving baby and juvenile copperheads a helping hand -- or a helping tail, as it were.

Copperhead Bites, Fangs and Venom

The copperhead has large venom glands on both sides of its head. These glands are located just behind the eye, and they account for the wedge-like shape of the snake's head. The venom glands connect to specialized fangs located toward the front of the snake's mouth. The copperhead's fangs can actually fold down when not in use, which prevents it from puncturing its own mouth.

Copperhead venom is comprised of a highly specialized protein called contortrostatin (among other substances). Like most of the other pit vipers, this species has hemotoxic venom. This means the venom attacks blood cells and tissues, starting locally at the site of the bite. Neurotoxic venom, on the other hand, attacks the nerves and central nervous system. Copperheads, water moccasins and most of the North American rattlesnakes have hemotoxic venom.

Interestingly, the venom of the southern copperhead (Agkistrodon contortrix contortrix) has been shown to slow the progression of cancer cells. [1] [2] Most of these studies have been conducted in rodents, a common first step in medical research. This type of snake venom could someday be the next big breakthrough in cancer treatment. Human trials in this area have not yet been conducted.

Copperhead venom is actually one of the least potent among the North American pit vipers. Water moccasins and rattlesnakes have a much more potent venom. This accounts for the lower mortality rate among humans who are bitten by the Agkistrodon species.

According to Dr. Peter Bromley, a specialist in Zoology, "copperhead bites are typically not fatal." [3] According to the Savannah River Ecology Laboratory (SREL), "copperhead venom is not very potent and deaths from copperhead bites are exceedingly rare." [4] According to the journal American Family Physician, "Bites from copperhead snakes, which are common in the eastern United States, seldom require antivenin therapy because they have the least potent venom and a negligible fatality rate." [5]

With proper medical treatment, there is good chance a human would survive a bite from this species. But you still need to treat these animals with respect and distance. The best way to view one of these snakes in the wild is from a safe distance. You should never try to approach or handle a copperhead, even if it appears to be dead or sleeping.

Irrational Snake Fears, Fueled by the Media

When researching this copperhead fact sheet, I came across an article in The News & Observer (a daily newspaper in North Carolina). In the article, the author referred to copperheads as the "venomous scourge of North Carolina," simply because they are considered dangerous to humans. This is the kind of selective and poorly researched "news" reporting that causes an irrational fear of snakes in much of the populace. The author was apparently more interested in turning a clever phrase than educating his audience.

Here is a broader and more factual perspective:

According to the CDC, about 4.5 million people are bitten by dogs in the United States each year. Of those who are bitten, nearly one in five (885,000) require medical attention. Additionally, according to a study from the division of public health in Raleigh, NC, an average of 19 deaths per year were recorded annually between 1979 and 2005. By contrast, venomous snakes only account for about 12 deaths each year in the U.S.

It would seem that The News & Observer writer defines a "scourge" as something that results in injury and death of humans. On this scale, dogs would rank higher than snakes. At least, when you actually consider the facts of the matter. The media needs to do a much better job in this area. They need to present the big picture once in a while, instead of using selective reporting and sensationalism. It's irresponsible and unprofessional.

Summary: 15 Interesting Facts About the Copperhead

You've learned a lot of information from this fact sheet. Here's a summary of some of the interesting points covered along the way.

The copperhead is a member of the Viperidae family. The snakes in this family are commonly referred to as vipers, a shortened form of their scientific name. The copperhead has heat-sensing pits located on either side of its head, midway between the nostril and the eye. Thus, it is known as a pit viper. It uses these pits to detect subtle variations between warm-blooded animals and their cooler background temperatures. Thus, a mouse will appear "hot" compared to the cool night air. This helps the snake hunt in low-light conditions. About 70% of snake species lay eggs. The other 30% give birth to live young. Like rattlesnakes and other pit vipers, the copperhead gives birth to live young. A baby copperhead has everything it needs to survive, including camouflage, fangs and venom. Baby copperheads are on their own from the very first day of their lives. Once they are born, they must fend for themselves. There is no parenting in the snake world. Baby copperheads have a particular survival tool that is lacking in the adult specimens. They have a brightly colored tail that helps them attract and kill prey (especially lizards and frogs). The snake's feeding habits will change as it matures, so the unique tail coloration fades into a normal coloration. Like rattlesnakes, this species has folding fangs in the front of its mouth. The fangs point downward when the snake strikes, allowing it to inject venom into its prey. When not in use, the fangs remain folded flat and tucked inside fleshy "sheaths." Copperheads have hemotoxic venom. This type of venom damages red blood cells and prevents clotting. It can also cause severe tissue damage in the area of the bite. Very few human deaths have been attributed to this species. In fact, most years go by without a single recorded death by copperhead bite. The venom of the southern copperhead (Agkistrodon contortrix contortrix) shows promise in halting the progression of cancer cells, though human studies in this area are lacking. This species has excellent camouflage that helps it blend in with the forest floor. The copperhead is one of the most widespread of North America's venomous snakes. It can be found in a total of 27 U.S. states, more than any other pit viper in the U.S. This snake falls into the same genus as the cottonmouth / water moccasin. Copperheads have been known to spend the cold winter months in communal dens. Communal means they share the den with other snakes, sometimes dozens of them. The males of this species can be aggressive and combative during the mating season. The males will often fight over a female by raising their bodies off the ground and trying to overpower one another.

The Australian Copperhead (species)

Most of the preceding information pertains to the American copperhead in particular (Agkistrodon contortrix). But there is also an Australian snake with the same common name. The Austrelaps genus includes three species of venomous snakes found in the southern and eastern parts of Australia. The Australian copperheads are elapids, which means they are members of the Elapidae family of snakes. This family also includes cobras and mambas. They are different in almost every way from the American species.

References

1. "Snake Venom Protein Paralyzes Cancer Cells." Robert Finn. Journal of the National Cancer Institute. http://jnci.oxfordjournals.org/content/93/4/261.full

2. "Contortrostatin, a dimeric disintegrin from Agkistrodon contortrix contortrix, inhibits breast cancer progression." Zhou, et al. National Institutes of Health. http://www.ncbi.nlm.nih.gov/pubmed/10966001

3. "How Dangerous are Copperhead Snakes?" by Whit Gibbons. NC State University website. http://www.ces.ncsu.edu/gaston/Pests/reptiles/copperhead.htm

4. Copperhead Species Profile. J.D. Wilson. Savannah River Ecology Laboratory. http://srelherp.uga.edu/snakes/agkcon.htm