Hognose snakes aren't scary - unless you're a toad

By Tim Lockley

Before you start writing me letters complaining that I already wrote about snakes back in April, this is different. In April, I wrote about snakes in the general sense. Today's article is about one specific snake; the hognose snake.

Last week, I received a photograph depicting a young man proudly holding the beaten corpse of a snake that his mother wanted me to identify. She was certain that it was "poisonous" but she couldn't find it on the Internet. What her son had clubbed to death was a hognose snake. More specifically, it was an eastern hognose snake and it was, even before its untimely death, completely harmless.

For a snake, the hognose is relatively slow moving. That's because its prey (toads and frogs) are fairly slow moving themselves. Probably because they're slow, they don't run away. Instead, they will put on quite a show if disturbed. Initially, a hognose will inflate its body to make itself look larger. It will also raise its head up and flatten and spread the skin around its neck into a hood. This will often be accompanied by a loud hiss -- loud enough to be heard quite a few meters away. It may strike, but it will do it with its mouth closed. This alone often is enough to frighten a potential predator away.

Should this display not have its desired effect, it will flip onto its back, defecating and throwing up its last meal. At this point, even a dog will assume that this is not a very appetizing target and will go off looking for something more toothsome. Finally, it will lie still with its mouth open, feigning death. It will even give off an odor similar to rotting flesh.

The name hognose comes from the its slightly flattened, upturned snout that it uses to dig up prey and to excavate sites to lay its eggs. They are day active during the warm months and spend the winter in deep burrows in loose sandy soil. Its main food source are toads.

Toads have evolved their own defense mechanisms to deal with predators. They have glands on their skin that emit toxins that make them unpalatable. They will also inflate their body to prevent a predator from swallowing it. The hognose has developed its own mechanisms to overcome these obstacles. A hognose has a large mouth with very strong jaws that can crush a frog or toad. If that doesn't work, they have two "fangs" way back in their mouth that they use to puncture their prey. Next to these teeth are glands that produce a toxin that may help to subdue a struggling toad. They also have adrenal glands that neutralize the toad's toxins.

As we continue to encroach more and more into these snakes' domains, unfortunate encounters such as the one documented in the photograph I received will continue to occur until such time as these fascinating, harmless creatures are so reduced in numbers that they will rarely be seen. And that will be a shame -- at least to me.

Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi MS 39535.