The harmless broad-banded water snake is a beautiful snake, with broad bands of olive, black, dark brown, and reddish brown patches separated by yellowish interstices. Those colors practically scream “copperhead” to the uninitiated, and even give many, if not most experienced herpers a start for a second or two when they happen upon one in the wild. It seems likely that this similarity is another example of Batesian mimicry (Wickler, 1968) that benefits the water snake by causing it to be mistaken for a copperhead, and thus to be given a wider berth — sparing its life — than would otherwise be the case. [...]
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The specimen in Walter’s possession seems clearly to be a ratsnake (all North American colubrids that were once included in the genus Elaphe could rightly be classified as ratsnakes, though the designation was not very precise), but how do we know that? it was not a Texas ratsnake (previously classified as Elaphe obsoleta lindheimeri, now as Pantherophis obsoletus) because it displayed — albeit imperfectly — a spearpoint marking on its dorsal crown, which character is wholly lacking in the Texas rat snake juvenile. Under the older, now-defunct nomenclature it would have been more accurate to classify it as Texas cornsnake (Elaphe guttata), which according to some (Conant & Collins, 1998; Tennant, 1998) was then represented in Texas by but one subspecies, the Great Plains ratsnake (Elaphe guttata emoryi), and to others (Werler & Dixon, 2000) by three separate subspecies, including — besides the Great Plains ratsnake — the type species known simply as the cornsnake (Elaphe guttata guttata) and the southwestern ratsnake (Elaphe guttata meahllmorum). [...] Like all things in life, fortunes sometimes favor the spider-eating-snake, and sometimes they favor the snake-eating-spider (and, just in case you hadn’t heard of a snake-eating-spider before, well… read on). [...] Notice the somber hues on the body of this snake. Olive gray along its spine and dorsum, two pale stripes on the side, the scales under the chin momentarily yellowish, but the yellow does not continue onto the belly (as would be the case with a yellow-bellied racer), but instead turning to a pale, mottled blue-gray just beyond the neck. This darker, blue gray marks most of the remaining belly, but not at the boundary of the belly and the sides, where the belly coloration grades to a pale white. [...] 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. [...] The eastern hog-nosed snake (Heterodon platirhinos) is a medium sized snake that comes in a variety of colors and markings. It has a stout body, a broad head and thick neck. When the snake is threatened, the skin of the neck and head spreads laterally, similar to that of a cobra. The eastern hog-nosed snake, however, is a harmless serpent (albeit with a mildly toxic saliva, and a pair of backward-facing fangs deep in its throat) that feeds on toads, frogs, rodents, and similar prey. [...] Most species of North American water snakes in the genus Nerodia (from the Greek, ναρος [pron. "nay'-ros"] = “flowing, liquid, wet” + δια [pron. "dee'-uh"] = “through,” thus “one who swims in water”) have a reputation for nasty dispositions, and as they grow larger, their mouths and teeth become correspondingly larger. [...] The Colubridae family of snakes includes 320 genera and about 700 species. Until the 1920′s (some authorities say the 1950′s) these snakes were considered utterly non-venomous. Not harmless, just non-venomous, as the word “harmless” cannot accurately describe a family, wherein certain members bite with teeth that pierce the skin and splatter blood. The wound often heals quickly, precisely because profuse bleeding cleans the punctures, and for true herpetologists that makes an occasional bite from a “non-venomous” snake an acceptable part of herping, not to mention a badge of distinction. Herping, one might say, isn’t for sissies… [...] This snake is one of three subspecies of Diadophis punctatus that are native to Texas. the prairie, regal, and Mississippi. Two of these (the prairie and Mississippi) display a nuchal (neck) collar, while the regal subspecies does not. [...] |
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