by Whit Gibbons

October 9, 2005

Autumn, like spring, is snake season. I don’t remember the last time I wrote about snakes in the fall. But based on the steady stream of recent emails with questions about snakes, I haven’t done so recently enough.

Many of the questions are “what is this snake?” and a digital photo is often sent along with the question. Others are questions about snake biology. The following questions were answered by J. D. Willson, a University of Georgia graduate student who responds to most of the queries that come from people visiting the Savannah River Ecology Laboratory herpetology Web site, or by me.

Q. I recently moved from Michigan, where we had one poisonous snake, to South Carolina, where I have heard there are four. Is this true?

A. You are correct that Michigan has only a single species of venomous snake, the massasauga rattlesnake. By moving to the Southeast, you have won the lottery on venomous snake diversity. Parts of every coastal state from Louisiana to North Carolina have six species. One reason people often think only four kinds of venomous snakes inhabit the South is that they include three rattlesnake species in a single category. These include the largest U.S. species, the eastern diamondback, and the smallest, the pygmy rattlesnake. The third is the canebrake or timber rattlesnake, the most common large species of rattler. The cottonmouth is a common resident around swamps, lakes, and streams throughout many southern states, and the copperhead is a more terrestrial species found throughout the Southeast, although it is absent from most of Florida. The sixth venomous species is the rare coral snake, a beautiful red-, yellow-, and black-ringed member of the cobra family. To find out more about these species, check out the SREL Web site (

One notable point is that of the more than 50 different kinds of snakes native to the eastern United States, only the seven species mentioned above are venomous. Most of the southeastern states have more than 40 species of snakes. If you decide to move to the Southwest, Arizona has more than 50 species, a dozen of them being rattlesnakes.

Q. Why do I see more snakes in the fall than in the summer? In fact, it seems like some snakes are as common now as they were in the spring.

A. Snakes are actually more common in the fall than in any other season because most U.S. snakes are born between July and September. Baby snakes often make their debut in carports or on patios in search of their first meal in early fall. By the time springtime arrives, many young snakes have already been consumed by predators, run over on roads, or died in other ways.

The prevalence of snake sightings in the fall is further increased as the adults move around more in search of suitable hiding places prior to hibernation. Hence, they are more likely to be seen. And some species, such as the canebrake rattlesnake, mate in the fall. Big male rattlesnakes are seen most commonly in autumn, crossing roads or wandering through woods and fields searching for females.

Q. How long do snakes live?

A. Zoo records exist of snakes living more than 25 years, and 10 year records are quite common. Although captive snakes can live for many years in a protective environment, no one really knows how long they normally live in the wild. One reason is that scientists have not discovered a way to tell the age of a live snake unless it was caught as a baby.

Q. I was told that snakes know when you are coming through the woods because they can hear you talking. Do they have ears?

A. No. Snakes do not hear the way most animals do. They do have a mechanism to sense vibrations on the ground, such as an animal walking, but presumably snakes cannot hear airborne sounds at all.

One reason that snakes are a maligned group of animals is that most people know little about their basic biology. Being unfamiliar with something you think could hurt you can lead to distrust and ill feeling. Educating the public is probably the single best step toward the conservation of snakes.

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