Eastern Copperhead Agkistrodon contortrix

Gravid female from Brown County

Identification

Perhaps the most often misidentified snake in Indiana, this is Indiana's most common venomous snake. However, you are still more likely to encounter a similar-looking, harmless snake than this species, in Indiana. Eastern Copperheads are light gray as juveniles with rich brown bands and a yellow-tipped tail that fades with age. Though some snakes become brown with dark mahogany bands as adults, others retain the light gray juvenile coloration. In nearly all individuals, the shape and pattern of the bands is diagnostic: dark brown hourglasses when viewed from the top, or Hershey kisses when viewed from the side. That is to say, that unlike every other blotched/banded snake in Indiana, the dark bands in Eastern Copperheads are thinnest on the top and become larger blotches on the side (Most banded snakes in Indiana have blotches that are large on the back and become thin or disappear on the sides). Though the coppery-orange head for which it is named is present on many individuals, it is not always present or obvious.

Adult from Brown County
Venter of adult from Brown County
Adult from Brown County

The unique hourglass-shaped bands on this species are usually the best way to differentiate it from similar, harmless snakes. Northern Watersnakes and Eastern Milksnakes are the most similar snakes, in terms of coloration and patterning, to Eastern Copperheads in Indiana. Both of these snakes are distinctively blotched and have smaller, narrower heads than Eastern Copperheads.

All four of Indiana's venomous snakes have thick bodies, broad chunky heads, elliptical pupils, heat sensitive pits between the eyes and nostrils, and undivided post-anal ventral scales (under the tail). However, most of these characteristics require close examination, elliptical pupils can dilate and become round, and many non-venomous snakes (especially Eastern Hog-Nosed Snakes) will broaden and flatten their heads in self defense. Therefore, it is always best to treat any snake that you cannot positively identify as potentially venomous. Venomous snakes are best left alone as most snake bites occur when someone attempts to handle or kill the snake. Snakes are not aggressive and do not hunt, attack, or chase people when left unmolested.

The non-venomous watersnakes (Nerodia) are commonly confused with Eastern Copperheads. However, Eastern Copperheads do not routinely stay around water, and none of the Midwestern watersnakes have the “hourglass” color pattern described above. Watersnakes also lack facial pits (seen in the picture above) that are present in all pit-vipers.

Ecology and Conservation

The Eastern Copperhead is typically found in high, dry, rocky and well-forested areas dominated by oaks and hickories. It can be found under and in logs, in cracks of foundations, under rocks and in deep leaf litter. Eastern Copperheads have a broad diet consisting of small rodents such as mice, lizards, amphibians and large insects. This species is secretive and tends to avoid areas with a lot of human activity. The Eastern Copperhead is active at night during the warmest part of the year and is more likely to defend itself when encountered in exposed situations. The Eastern Copperhead typically mates in the late spring but some individuals may mate in the fall before returning to their hibernacula. Gravid females can often be found in aggregations at or near hollow logs or rocky crevices where they typically give live birth to 4-8 young every other year.

Within its range, the Eastern Copperhead is likely the most common venomous snake in the Midwest.

Rocky bluff in Clark County
Mesic forest in Brown County

Distribution

Eastern Copperheads are most abundant in the unglaciated hills of south-central Indiana and frequent rocky outcrops, ridgetop forest openings, and hollow logs. This species only extends into central and northern Indiana along a narrow system of hills and ravines associated with the Wabash River watersheds; predominantly along Sugar Creek in Parke County (where the snakes are apparently now rare). Outside of this small region, Eastern Copperheads do not occur in the northern half of the state. They are also relatively rare in southeastern and southwestern Indiana, inhabiting only scattered rocky ravine systems. Despite popular belief, Eastern Copperheads do not have a proclivity for inhabiting water bodies. Much to the contrary, they are most often denizens of high, dry, rocky ridges that only occasionally wander to the water's edge to hunt amphibians or disperse.

Taxonomy

Traditionally, a several subspecies were recognized within a single, wide-ranging species--the Copperhead (Agkistrodon contortrix). Under this taxonomic arrangement, Indiana was home to the Northern Copperhead (A. c. mokasen). Alternatively, Burbrink and Guiher (2015) recognized two species and no subspecies; under this arrangement, Indiana is home to the Eastern Copperhead (Agkistrodon contortrix). These snakes are members of the family Viperidae, which is represented by a total of four species in Indiana.

Literature Cited

Burbrink, F. T. and T. J. Guiher. 2015. Considering gene flow when using coalescent methods to delimit lineages of North American pitvipers of the genus Agkistrodon. Zoological Journal of the Linnean Society 173:505-526.

Conant, R. and J. T . Collins. 1998. Reptiles and Amphibians of Eastern and Central North America. Third Edition, Expanded. Houghton Mifflin, New York, NY.

Minton, S. A. Jr. 2001. Amphibians and Reptiles of Indiana. Indiana Academy of Science, Indianapolis, IN.

Distribution Map
Distribution map of Eastern Copperhead (Agkistrodon contortrix)
Photographs