— This article by Jerry Cates, first published on 4 September 2011, was last revised on 23 October 2013. © Bugsinthenews Vol. 12:09(01).
Important related links:
Snake Exclusion: How to Snake-Proof your Yard & Home.
Definition: A Reasonably Snake-Free Environment.
Snake Repellents: How, and How Well, do they Work?
Weeds, Rodents, and Snakes…
Among the first casualties of a drought are most of our normally lush, green seed-bearing grasses and weeds. In a good year, these line our roadways and carpet our meadows. Throughout the typical growing season they produce zillions of seeds.
Seeds produced by weeds and grasses feed a multitude of animals, including a range of rodents — mice, rats, voles. shrews, and squirrels. But in a bad year — as in a drought — the grasses and weeds, along with their seeds, all but disappear, and in their absence rodents suffer. In a serious drought, the subsequent reduction in rodent populations can be dramatic.
What’s not to like about that? Rodents destroy and contaminate our crops and stored grains, among other things, all generally bad. But in a drought crop production plummets, too, so — all in all — the result of a drought is mostly in the negative column of the balance sheet.
Ask any snake.
Snakes and rodents go together, at least from a snake’s perspective. Not all snakes eat rodents, but most species do, and a large percentage of our snakes prey on rodents almost exclusively. When rodent numbers sink, snakes go hungry, so you might guess that the snakes are very hungry right now (early September 2011). The hungrier the snakes get, the more they start ranging afield, looking for something to eat.
Note: The recent devastating wildfires in Texas and other states affected by drought are expected to make snakes even more visible than usual. When entering any area affected by drought, particularly areas that have been burned by wildfires, and — before long — such areas that will be flooded by the heavy rains that often come in the aftermath of drought, be aware that snakes are often sighted in such places. Most of the time these snakes will be hungry and irritable.
When you spot a snake anywhere in the wild, the best thing to do — under most circumstances — is to leave the snake alone; watch it, and alert others in your party to its presence, then let it go about its business (most snakes will normally focus on getting out of your sight as quickly as possible.) If you are determined to kill the harmful, venomous snakes you find, do your best to distinguish between them and and their harmless cousins, and try to let the harmless ones live another day. They do much good for man by keeping our rodent population from getting out of control.
Looking for Food in all the Wrong Places…
As a result of the drop in rodent populations, we can expect snakes to show up in places where they are seldom seen. It isn’t so much that there are more snakes over-all, because snake populations, like those of rodents, drop during a drought. But if this drought is like most that we’ve had in the past, the snakes are more visible than normal, and we’ll see them in places they aren’t normally found.
So what happens if you see a snake in your back yard, or on the trail? If it’s a large snake, the first thing you should do, interestingly enough, is to take a good hard look at its eyes. If the eyes are large, round, with big black pupils that are easy to see, it’s almost certainly NOT a venomous species. In the photo at left, the large round eyes with black pupils, in this corn snake (a harmless rat snake) shows that it is not venomous.
If, on the other hand, its eyes have cat’s eye pupils and are somewhat difficult to see (because they blend in with the snake’s face), that’s a bad sign, as all of our rattlesnakes, copperheads, and cottonmouth snakes have such eyes. A few of our non-venomous snakes do, too, but they’re rare.
The three most common types of venomous snakes in Texas are the rattlesnake, the copperhead, the Texas coral snake, and the cottonmouth. It is a good idea for anyone living in snake country to know how to identify the venomous snakes in your area.
Copperheads have a reddish or pinkish, copperish cast to their skin, with dark copperish bands or hour-glass shaped markings on their sides. In the photo below, notice the eyes with the vertical, slit-like, cat’s eye pupils. This is the head of a broad-banded copperhead found in Round Rock, Texas. Notice how the eyes blend in with the face, making them somewhat harder to make out.
The rattlesnake has a distinctive set of rattles at the end of the tail, but don’t expect the snake to use its rattles every time it encounters a threat. Just because you don’t hear the tell-tale sound, don’t automatically assume it’s not a dangerous rattlesnake.
Look for the end of the tail.
If you see the rattle, that’s a positive identification for a venomous rattlesnake.
If it is long and pointed (i.e., there isn’t a rattle, and the tail is intact), it isn’t a rattlesnake, but it could still be a venomous cottonmouth or copperhead, even a dangerous coral snake.
If it’s blunt, without a rattle (i.e., the tail isn’t intact), it could be one of our venomous snakes, or — just as likely — any of our numerous, nonvenomous, harmless serpents. All species of snakes, including rattlesnakes, are subject to losing the tips of their tails to animals, traps, and hoes…
If it is a colorful, banded (or seemingly banded) snake, the Boy Scout nursery rhyme really does tell you whether the snake is dangerous or not:
“Red touch yellow, kill a fellow. Red touch black, venom lack.”
That simple verse is probably the best way to remember how to tell a coral snake from one of our other colorful, banded and apparently banded (where the markings do not completely encircle the snake’s girth) serpents. Just remember that the rhyme doesn’t work in Central or South America, and in southern Mexico, where certain local species of coral snakes can be found with markings that violate that rule.
Snakes will almost always retreat when confronted by humans, and many people are startled by how fast snakes can travel.
If the worst happens, and the snake does bite, get to the doctor as quickly as possible.
Snake bites are sometimes less painful than a sting from a scorpion or a wasp, when the actual bite occurs, and though the bite wound usually starts to hurt soon afterward, the victim may not experience the effects of the venom right away. As anybody who has seen movies ranging from ‘Lonesome Dove’ to ‘True Grit’ can attest, snake bites are nothing to mess with.
In the photo at left, the sheaths around the fangs of a diamond-backed rattlesnake found in Cedar Creek, Texas, have been removed to reveal the bare fangs. Although the fangs of rattlesnakes in this species are relatively short (reaching a record maximum of 7/8ths of an inch) they can penetrate up to twice this depth during the bite, as the skin and fatty tissue are compressed by the snake’s mouth.
The venom will begin kicking in, sometimes right away, sometimes in as much as a few hours, and — for rattlesnakes, copperheads, and cottonmouths — generally produce serious swelling of the bite wound and surrounding tissues relatively quickly. Removing all rings and other hardware from the body is imperative as soon as the bite occurs, to avoid serious complications from the swelling that will soon take place.
For a coral snake bite, symptoms may not be noticed immediately, but when they kick in they present as serious medical symptoms such as paralysis and respiratory failure. By that point, if the person who has been bitten is not being treated with antivenin, it could be too late to reverse the symptoms. The lesson? Get to the doctor right away. Don’t even wait to try to suction the venom out (studies show that doesn’t provide much in the way of benefits, and can make things worse).
In the photo of the Texas coral snake mouth shown below, the pair ot white blobs in the roof of the mouth are fangs sheathed in tissue. The Texas coral snake’s fangs average about 1/8th inch in length, so it is difficult for the snake to bite through clothing or even a thin layer of leather. Bare skin, on the other hand, is very much at risk, as is skin covered by thin cloth or socks with a loose weave.
Not only is a snake bite painful, but being on the receiving end can drain your wallet as well. If you are bitten by a venomous snake, you and your insurance provider together will likely spend between $10,000 and $150,000 in medical bills. Even a minor bite from a venomous snake will cost $10,000; if the bite is more serious, and plastic surgery is needed, total costs can approach, and even exceed, $150,000.
That, by itself, should encourage us to put the flip-flops aside, and wear leather boots whenever we’re out walking in or around tall grass, brush, or while doing gardening work or lawn mowing. Even better is to wear heavy denim jeans over our boots. Every bit of extra material between our skin and a snake’s fangs helps provide a measure of protection against the bite of a venomous snake.
Even if rains do come soon, and the drought is broken, expect to see snakes where they are not usually seen for some time. The snakes will be out looking for their favorite prey, and a couple of rains won’t suddenly produce a crop of rodents for the snakes to eat.
Related Links on BugsInTheNews:
- North American Snake Markings & Coloration Guide.
- Ophidian Dentition — Snake Teeth & Fangs — Morphology & Specialization
- Snake Anatomy, Physiology, and Taxonomy.
- Snake Exclusion — How to Snake-proof your Yard and Home.
- Snake Repellents — How, and How Well, do They Work?
- Snakebite First Aid
- What is Meant by “A Reasonably Snake-Free Environment”?
- Cottonmouths & Copperheads in Travis and Harris Counties, Texas — June to August, 2010
- Western Cottonmouth (Agkistrodon piscivorus leucostoma, Troost 1836); Tammy D., Santa Fe, TX — 28 Aug 2011
- Western Diamond-backed Rattlesnake (Crotalus atrox, Baird & Girard, 1853), Cedar Creek, TX — 22 Oct 2010
References to Scientific Articles, Books, and Papers:
- Arikan, Hüseyin et al. 2008. Electrophoretic characterisation of the venom samples obtained from various Anatolian snakes(Serpentes: Colubridae, Viperidae, Elapidae). N.W. J. Zool. Vol. 4, No. 1, pp.16-28.
- Birchard, Geoffrey F., et al., 1984. Foetal-Maternal Blood Respiratory Properties of an Ovoviviparous Snake; the Cottonmouth, Agkistrodon piscivorus. J. exp. Biol. 108, 247-25
- Chao, Betty H., et al. 1989. Agkistrodon piscivorus piscivorus platelet aggregation inhibitor: A potent inhibitor of platelet activation. Proc. Natl. Acad. Sci. USA Vol. 86, pp. 8050-8054
- Chippaux, J. P., et al. 1991. Snake Venom Variability: Methods of study, results, and Interpretation. Toxicon Vol. 29, No. I I , pp. 1279-1303.
- Conant, Roger, and Joseph T. Collins, 1998. Reptiles and Amphibians — Eastern/Central North America, Third Ed. Peterson Field Guides. Houghton Mifflin Co.
- Cundall, David. 2009. Viper Fangs: Functional Limitations of Extreme Teeth. Physiological and Biochemical Zoology 82(1):63–79.
- Deufel, Alexandra, and David Cundall. 2004.Functional plasticity of the venom delivery system in snakes with a focus on the poststrike prey release behavior. Zoologischer Anzeiger 245 (2006) 249–267
- Grachevca, Elena, et al., 2010. Molecular Basis for Infrared Detection by Snakes. Nature, 15 April 2010.
- Greene, Harry W., 1997. Snakes: the Evolution of Mystery in Nature. University of California Press.
- Schulz, Klaus-Dieter, 1996. A Monograph of the Colubrid Snakes of the Genus Elaphe Fitzinger. Koeltz Scientific Books.
- Tennant, Alan,1998. A Field Guide to Texas Snakes, Second Ed. Gulf Publishing.
- Weinstein, Scott A., et al. 1994.Reptile Venom Glands — Form, Function, and Future. Handbook of Venoms and Toxins of Reptiles. CRC Press.
- Werler, John E., and James R. Dixon, 2000. Texas Snakes. University of Texas Press.
- World Health Organization. 2002. Management of Snakebite and Research. WHO SEA-RES-2.
- Zaidan, Frederick III, 2002. Variation in cottonmouth (Agkistrodon piscivorus leucostoma) resting metabolic rates. Comparative Biochemistry and Physiology Part A 134 (2003) 511–523
- Zamudio, Kelly R., et al., 2000. Fang tip spread, puncture distance, and suction for snake bite. Toxicon 38 (2000) 723 – 728
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