POST-GAZETTE (Pittsburgh, Pennsylvania) 13 March 05 Timber rattlesnake a part of Pennsylvania's heritage (Ben Moyer)
The 220 attendees at last week's annual Biodiversity Conservation Conference at Shippensburg University learned about threats to Pennsylvania's hemlock forests from an exotic insect, the state's two species of flying squirrels, the renewed Pennsylvania Breeding Bird Atlas project and much more. But the most compelling session dealt with a wild creature that inspires every human reaction ranging from fear and hatred to fascination and respect.
Chris Urban, chief of the Fish and Boat Commission's Natural Diversity Section told conference-goers about his agency's efforts to understand and protect the timber rattlesnake.
The timber rattlesnake is one of three venomous reptiles known to inhabit Pennsylvania. The others are the northern copperhead, which ranges across the southern two-thirds of the commonwealth, and the smaller massasauga rattlesnake in a few scattered relicts of meadowland habitat in far western counties.
Though it probably once thrived everywhere in Pennsylvania, the timber rattlesnake is now confined by agriculture, urban development and deliberate persecution to the most remote mountainous territory in the state.
Urban and other biologists believe populations of timber rattlers declined significantly in the past several decades, and that many local populations were completely destroyed. Habitat destruction, taking snakes for the reptile collector trade, unregulated snake hunts and killing snakes in casual encounters have all diminished this rattlesnake's numbers and range.
Much of the needless destruction of rattlesnakes can be pinned on ignorance. People such as Urban, who handle rattlesnakes regularly, know the animals are not vicious killers, waiting to sink their fangs into human flesh. Urban said rattlers avoid human contact at every opportunity.
They are usually timid creatures that use their fangs and venom for one reason -- hunting mice, chipmunks and other small mammals for food.
For the past three years Urban and a statewide team of assistants have been studying rattlesnake movements and habitat. Their work is building a wider understanding of how rattlesnakes use the rocky "den" sites that serve as a home base, why people sometimes encounter rattlers around their camps or homes, and why the taking of only a few snakes can slash local rattlesnake populations beyond the point of recovery.
Urban's teams have spent the past few summers in the rockiest most remote places remaining the state. They have followed every lead to find and document rattlesnake den sites. When they find a population of rattlers, they mark some snakes by injecting a tiny transmitter, the size of a grain of rice, inside the body cavity. The researchers can then follow electronic signals from the transmitter to study rattlesnake movement and behavior.
They have learned that the places most snake hunters and collectors think of as "dens" are not dens at all. These exposed rocky ledges and boulder fields are actually "basking areas" where gravid (pregnant) females spend the summer soaking up warmth and gestating their young (rattlesnakes bear live young, five to nine per litter). The biology of a timber rattlesnake requires that adult females breed and birth only once every two to four years. The process is so taxing that females need the intervening time to forage and accumulate body fat to ensure successful reproduction in the future. Consequently, taking even a few snakes from basking areas can seriously hinder the population's naturally low reproductive potential.
The actual dens are not so conspicuous and are generally in the forest where voids and fissures offer access to underground security. Rattlers emerge in mid- to late-April, and males rove widely in the summer, often 2 or more miles from the den, foraging and searching for available females by scent.
Urban said most of the remaining habitat is in north-central Pennsylvania but showed a map of inventoried sites. Urban's map shows that the Laurel and Chestnut ridges in Fayette, Somerset and Westmoreland counties still offer one of the most dense concentrations of rattlesnake sites in the state.
As a result of Urban's work the Fish and Boat Commission is refining its regulation of rattlesnake hunting and collecting. A rattlesnake hunting permit is now required to hunt or possess a rattlesnake, and only one snake may be collected per year.
For more information on the timber rattlesnake, check the Fish and Boat Commission's Web site at www.fish.state.ps.us.
http://www.post-gazette.com/pg/05072/470583.stm

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