American Copperhead
Southern Copperhead
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Order:Squamata
Family:Viperidae
Genus:Agkistrodon
Species:contortrix
Binomial name
Agkistrodon contortrix

The American copperhead (Agkistrodon contortrix) is a species of venomous viper native to eastern North America. Mature copperheads have a beautiful coppery colored head and neck. They tend to be smallish snakes, generally about 50 cm long (1.5 ft) , but specimens up to 1 m long (3 ft) have been encountered. The body is thin by pit viper standards. There are four clearly defined subspecies.

  • The Northern copperhead (Agkistrodon contortrix mokasen, is found throughout the northeastern United States It is reddish brown overall, with a number of chestnut-colored "hourglass" markings running down its back.
  • The Southern copperhead (A. contortrix contortrix) of the south-eastern United States is generally paler and has more clearly defined markings, sometimes including a row of dark triangular marks the sides of the body.
  • The Broad-banded copperhead (A. contortrix laticinctus) of Kansas, Oklahoma and Texas is sometimes considered the most attractive of the four. It tends to be smaller than the Northern and Southern races, rarely being longer than about 75 cm, and has wide bands across the back which are not narrowed at the spine.
  • The Trans-Pecos copperhead (A. contortrix pictigaster) is similar to the Broad-banded, is of equal size, and has has slightly hourglass-shaped markings, usually with a lighter patch at the base of each band.

The genus Agkistrodon, of which the American copperhead is a member, includes 10 species, three of them native to North America (one being the well-known Cottonmouth. The remainder are found in Asia and the islands nearby, notable members include the Siberian moccasin, the Himalayan viper, and the Okinawan habu. Note that the three Australian copperheads are elapidss and not related.

American copperheads breed in late summer but not to a fixed pattern: sometimes a female will give produce young for several years running, then not breed at all for a time. They give birth to live young about 20 cm long: a typical litter is 4 to 7, but it can be as few as one or as many as 20. Their size apart, the young are similar to the adults, but lighter in color, and with a yellow-marked tip to the tail, which is used to lure lizards and frogs.

Like all pit vipers, American copperheads are ambush predators: they take up a promising position and wait for suitable prey to arrive. Roughly 90% of their diet is small rodents: mice, voles, and similar creatures.

American copperheads are venomous but almost never deadly to humans. They have an efficient venom delivery system, with long fangs mounted at the front of the jaw which swivel back to allow the snake to close its mouth, but their primary role is to kill mice quickly: the amount of venom a single American copperhead can deliver is insufficient to kill a healthy adult human. It does, however, produce immediate and intense pain, followed by tingling, throbbing, swelling and severe nausea.

In the state of Missouri, for example, about 200 people suffer from snakebite each year, mostly from copperheads, but there are no records of deaths resulting. Although an antivenom exists, it is not usually administered as the risk of a death through an allergic reaction to the treatment is greater than the risk of the snakebite itself.

The best way to avoid being bitten if you hike or live in copperhead country is to be aware of their typical behavior and habitats and take appropriate precautions. Like most North American vipers, copperheads prefer to avoid humans and will leave the area without biting you if you give them the opportunity. However, unlike rattlesnakes, they cannot make a loud noise to warn you of their presence. They are rumored to smell like cucumbers, but this appears doubtful.

Avoid placing your hand in small hiding places (niches in rock walls, woodpiles, etc.) without looking for a snake first, do not blindly jump over a fallen log (stand on it or bend over it to look for a snake first), and wear stout leather hiking boots. Unless you have a reason for walking lightly, tramping your feet will let the snakes know that you are around, as they can sense ground vibrations. The majority of snakebite incidents are the result of attempting to handle the snake.

If bitten, do not apply a tourniquet or cut gashes or suck blood—keep calm and get to the nearest hospital as quickly as possible.

The scientific name is derived from the Greek agkistron (a fish-hook) and odon (a tooth); a reference to the curved fangs, though of course they are not barbed; and from the Latin contortus (full of turns, twisted).