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Batesian Mimicry of Western Pygmy Rattlesnakes by Eastern Hog-nosed Snakes in the Sam Houston National Forest

Recently, Tom was surveying a portion of the Sam Houston Nationaf Forest for additional specimens of the western pygmy rattlesnake (Sistrurus miliarius streckeri). He knew that serpent was common to the area, as he had found several there in the past; in fact, the specimen whose ph0tograph is posted here was found in that area, on the path he was now surveying. Suddenly, he came upon an eastern hog-nosed snake (Heterodon platirhinos) on the same path and was amazed at the similarities in colorations and markings. “At first glance,” he admitted, “I actually thought I’d come upon a Sistrurus.” It is obvious why Tom, one of the most experienced herpetologists in the world, could have been fooled — if only for an instant — into mistaking this particular eastern hog-nosed snake for a western pygmy rattlesnake. They are remarkably similar, and — most likely — the resemblance is not coincidental. […]

Western Pygmy Rattlesnakes in the Sam Houston National Forest

The western pygmy rattlesnake is a smallish, gray-brown or pale gray rattlesnake, usually with short, distinctive lateral marks, wider than long, regularly spaced along its spine, and one to three rows of small splotches on its lateral body. A pale orange wash extends along the spine as a series of short dashes that separate the spinal bars without encroaching on them. The effect is of an indistinct orange spinal stripe, but on close examination one can see that the “stripe” is actually broken up between each bar. […]