SAN ANGELO STANDARD TIMES (Texas) 25 September 05 Diamond-backed rattlesnake is legendary (Dr. Terry Maxwell is a professor of biology at Angelo State University)
If ever there was a legendary beast in the Texas countryside, surely the rattlesnake is it - more specifically, the western diamond-backed rattlesnake.
Its position in rural lore is well-deserved. Let me count the ways.
This is very nearly the largest venomous reptile in Texas, being second only to the slightly heavier eastern diamond-backed rattlesnake.
Although the average adult length today is between 3feet and 4 feet, according to Werler and Dixon in their book, ''Texas Snakes,'' 6-foot-long specimens are well-documented from South Texas.
Rational caution is advised about claims of larger rattlesnakes. Who doesn't love a spine-tingling, hair-raising story about a giant poisonous snake?
The problems are that a snake's skin stretches by as much as 35 percent of the animal's original un-skinned length. That can make a 4-and-a-half-foot snake into a 6-foot skin.
Photographs become easier to fake or exaggerate as each day goes by.
Western diamond-backed rattlesnakes are among the more common snakes in Texas, even when you consider harmless species. In particular, they flourish in prickly pear cactus patches. There, they encounter wood rats - a favorite prey - and other small mammals. There are apparently valid accounts of these rattlers occurring in optimal habitats at densities of 60 per square mile. I doubt that such population levels are regular across much of Texas, but throughout the western two-thirds of our state, they are common.
One study published in 1964 estimated 1,400 venomous snakebites annually in Texas. Most of those came from western diamond-backed rattlesnakes. Ounce for ounce, the venom of this species is not the most toxic, but its aggressiveness, great striking distance, long fangs, large venom capacity and continued abundance easily make it the most dangerous.
An unexpected feature of western diamondbacks is that the bite from a snake less than a year old can be far more serious than from an adult snake. Even though the young rattler can inject less venom, its venom has been recorded to be as much as 6.6 times as toxic as adult rattler venom. At least one cause of this is a quality of young rattler venom that retards production of clotting fiber in blood, thus causing far more internal bleeding in the victim.
As well as I can remember, I've only been struck at once and never hit. I was walking a dirt road on the Devil's River State Natural Area in Val Verde County when one missed me by less than a foot. You need to understand that I have spent much of a lifetime in the West Texas out-of-doors, but I practice rattler caution.
Western diamond-backed rattlesnakes can strike easily from one-third to one-half of their body length, a major cause of their danger to humans. With its back to a solid object, one can strike its entire body length. That ought to sober you up.
What we all hope for, and often benefit from, is the tendency of these vipers to rattle before we get close enough to provoke them striking.
They do not always rattle, and they sometimes wait until we're too close before they rattle, but on the whole we usually are warned.
Rattlesnakes cannot be aged by their rattles. A rattle segment is produced each time they shed. In so-so years, an adult will shed three or four times. In good food-availability years, they'll shed five or more times. And the reason you typically don't see, say, a 5-year-old rattler with 20 or more rattle segments, is that the rattles frequently break.
I am reminded by all this of a young man I taught several years ago. He was a student of agriculture at ASU and was studying the effects of the herbicide Picloram for controlling prickly pear cactus - a study that necessitated his walking through cactus thickets.
Sure enough, one day an adult rattler struck at him with such force that it nearly knocked him on his back. He did not quite lose his balance and was uninjured by the snake. He was wearing snake leggings - considered by some to be a joking matter, but not by me or him. Consider yourself well-advised.
Diamond-backed rattlesnake is legendary