CLARKE TIMES COURIER (Virginia) 01 June 05 Pit vipers in the county (Sara and Jim Lawrey)
Pit vipers! The words alone elicit fear and loathing from most of us. Although snakes are not everyone's favorite group of animals, most of us take a "live and let live" attitude with them. Except the venomous ones.
By anyone's definition, though, venomous snakes are fascinating. And perhaps armed with more knowledge about them, one might even find them worthy of respect and admiration.
There are two venomous snakes in Clarke County, the copperhead and the timber rattlesnake. Both are pit vipers, snakes that have a small membrane-lined hole between the eye and nostril that aids in the detection of warm-blooded animal prey at night. Pit vipers also have eye pupils as vertical slits, thick triangular heads, keeled body scales and the ability to inject hemotoxic venom from hollow fangs that are rotated into position prior to a strike. The rattlesnake members of this group produce a scaly rattle on the tip of the tail.
The copperhead (Agkistrodon contortrix L.) is a pinkish-brown, thick-bodied snake with obvious reddish-brown, saddle-shaped dorsal bands. It is common throughout Virginia, especially in oak-hickory forest with rock crevices and slides.
The timber rattlesnake (Crotalus horridus L.) is a large snake with transverse dorsal bands on a background color that is either yellow-gray (light-phase morph) or dark brown to black (dark-phase). In Virginia the timber rattler is found only in the mountainous western counties in rocky woodlands.
The copperhead and timber rattlesnakes have similar annual behavior patterns. They are active from April to October, preferring to hunt during the day in spring and fall and at night during the heat of the summer. They are "sit and wait" predators that ambush unwary prey, usually small mammals but also birds, frogs, and even insects. They inject prey with venom and swallow the incapacitated bodies whole.
In the late fall snakes of both species migrate to communal wintering dens every year where they form large, sometimes mixed groups of dozens, even hundreds, of individuals. The dens are generally rocky ledges in wooded areas with large cracks and crevices that provide protection during the winter.
In early spring, snakes emerge to bask near the dens on sunny rocks. Basking is also a communal behavior with individuals wrapping around each other to form masses of scaly coils. As the temperatures climb, males, juveniles and non-pregnant females move away separately to feed all summer.
But not the pregnant females. They remain nearby and bask communally as embryos develop in their bodies over the summer. During this period they generally do not eat. Around August, females give birth to live young in communal birthing rookeries. Mothers continue to forgo feeding during the first 7-10 days after parturition to defend the baby snakes (which are venomous at birth).
It isn't until young begin to move away from the rookeries that mothers finally begin hunting for themselves again. Not surprisingly, females in these species are capable of producing young only every 3-4 years during which time they build up fat reserves that are consumed during this arduous process.
Baby pit vipers are subject to predation by hawks, foxes, skunks and other snakes, but adult snakes have few predators except humans. In the past bounty hunts have targeted the vulnerable wintering dens and all but eliminated timber rattlers from many northeastern states. Various organized hunts and "rattlesnake roundups" are still carried out in some states.
Hunting of these snakes has always been justified because of the perceived threat they pose to humans. But what is the threat? In North America, about 8,000 people are bitten by venomous reptiles, mainly snakes, each year. Bites almost never result in death, but they are painful and damaging and require immediate medical attention. Some people are bitten after stepping on basking snakes in the woods or along trails. But most bites are to people who try to handle them, many to people who keep them as pets. If there is a threat from these snakes, it would appear to be similar to that posed by other dangerous animals best left alone.
Given that these snakes are complex, social, long-lived (they can live up to 30 years) animals that pose no particular threat to us, we would argue that they should be left alone, especially in dens. Threats to pets and livestock can justify killing individual animals, but widespread slaughter of animals in remote communal wintering or birthing sites is unjustifiable, in our opinion.
Pit vipers in the county