SNOMNH Herpetology Blog

Adults of the Timber Rattlesnake or "Velvet-tail" (left) and the Western Diamondback or "Coon-tail" (right).

Two common rattlesnakes, the Timber Rattlesnake (Crotalus horridus) and the Western Diamondback (Crotalus atrox), are known to many locals as Velvet-tails and Coon-tails, respectively. The reasons—Timber Rattlesnakes have black tails that have a velvety appearance, particularly just after they shed their skin, and Western Diamondbacks have black and white banded tails similar to those of raccoons. Both of these snakes can be considered very dangerous because they have toxic venom, and they can reach large sizes and thus produce a lot of venom.

Most commonly seen in Spring and Fall, both species aggregate in den-sites to overwinter, and both species bask in the open (often on dirt or paved roads) to gain heat on cooler days. These snakes are native to Oklahoma, with Velvet-tails occurring in the eastern half of the state and Coon-tails occurring across most of the state. Extreme care should be taken when relocating or handling these snakes, and our best advice is to leave them alone. The good news is that if one shows up in your yard, it is likely just passing through and will be gone in a few days.

As the weather cools off in late fall, most snakes disappear, seeking refuges in which to spend the winter. In our amphibian and reptile studies in southeastern Oklahoma, we have captured very few snakes during the last two weeks. Only two were captured during the third week of October, and both were juveniles. One was a young Eastern Racer (Coluber constrictor) and the other was a young Prairie Kingsnake (Lampropeltis calligaster). Both of these are common snakes, but most people do not see Prairie Kingsnakes very often because they are nocturnal and very secretive. Eastern Racers, on the other hand, are very common, and the are the most frequently seen snakes crossing roads during Spring, Summer, and Fall, but only during the day. Because they are very wary and slither rapidly, they are difficult to catch. In addition, when grabbed, the frequently bite! The good news is that they are non-venomous and they are only biting because they are frightened. They are completely harmless, and like most nonvenomous snakes, their bites do not cause infections.

Juvenile Eastern Racer (left) and Prairie Kingsnake (right).

One way to determine the species of amphibians and reptiles that occur in an area is to use a drift fence.  Our fences are constructed from stiff vinyl held up by pieces of rebar.  The Y-shaped design has a bucket in the center, buried flush with the ground, and two wire minnow traps on either side of the ends of the fences—see the photograph.  We have 17 of these drift fence arrays at our study site in southeastern Oklahoma.  As animals move through an area, they encounter the fence and follow it to the right or left, ending up either in the center bucket or a trap at the other end.  Drift fences must be checked every day so that animals do not spend very long in the traps. We will periodically let you know what we are finding in our traps.

We have already started some long-term studies on snakes. We use “pit-tags” to identify individual snakes so that we can follow their movements and keep records on growth. Pit-tags (passive integrated transponders) injected under the skin of snakes work like price codes on things that you purchase. We simply read each snake’s “code” with a scanner every time that we capture it. Pit-tags don’t bother the snakes at all.

A drift fence used to capture amphibians and reptiles. Wooden squares are used to shade the traps from the sun, and large sponges provide moisture and protection for animals in the bucket.

Newborn Pygmy Rattlesnakes, which are born alive in late August or early September, are very small and dificult to observe. Nevertheless, they are venomous when they are born and they should not be handled.