Hearing the rattle of a venomous snake's tail can drive fear into a person enjoying the outdoors.
However, that rattling snake can be an important part of the ecosystem.
Dr. Thomas LaDuke, an associate professor of biology at East Stroudsburg University, has been keeping an eye on Pennsylvania's timber rattlesnake population for the last several years.
Timber rattlesnakes are one of three venomous snakes that are native to Pennsylvania. The others are the more common copperhead and the rarer eastern massasauga.
LaDuke received a Pennsylvania Fish and Boat Commission grant in 2015 to track the Commonwealth's timber rattlesnake population.
"If you know where to go and where to look," LaDuke said, "you can do a quick count and get a rough estimate of population size."
LaDuke and a group of volunteers go to known timber rattlesnake colonies--LaDuke estimates there are over 1,000 colonies in Pennsylvania--and catch the snakes with snake tongs and snake sticks. They bag the snakes then release them into tubes. Once the snakes' heads are in the tubes, the group can safely handle the vipers.
Volunteers place passive integrated transponder tags, or PIT tags, under the snakes' skin. They are similar to those used with cats and dogs. Using a bar code device, they can keep track of individual snakes.
Timber rattlesnakes can be found in most of the eastern U.S. LaDuke said populations have decreased over the years, particularly in the northeast.
While numbers continue to decrease in other northeastern states, Pennsylvania's population seems to have stabilized in recent years, according to LaDuke.
LaDuke credits the Pennsylvania Fish and Boat Commission's policies for the stabilization. Timber rattlesnakes are a protected species in the state. People may not legally kill or capture the snakes without a permit and commercial sales are restricted.
A healthy rattlesnake population helps prevent the spread of Lyme disease, LaDuke said.
LaDuke said he believes there is a correlation between a decrease in timber rattlesnake populations in the northeast and the increase in reported Lyme disease cases.
The thousands of timber rattlesnakes in the state help keep small mammal populations under control, LaDuke said. Each year, an individual snake can consume dozens of ticks that are attached to rodents and other small tick-carrying critters, he said.
"There's been an explosion of forest rodents," LaDuke said. "White-footed mice. Chipmunks. Timber rattlesnakes suppress those populations that help spread the disease."
Timber rattlesnakes can slither along for up to 30 years. However, they do not reach sexual maturity until they are about 5 to 9 years old.
That means, if timber rattlesnakes are killed in large numbers, they have difficulty regenerating populations, LaDuke said.
LaDuke's grant ends by the end of 2019 but he said he is working with the commission to develop an ongoing tracking program.
How to spot a venomous snake.
Pennsylvania's venomous snakes are in the pit viper family. Pit vipers are so named because of the deep pits on the side their heads used to detect the warmth of nearby prey.
Pennsylvania's pit vipers have venom sacs that give their heads a triangular appearance, as opposed to nonvenomous snakes that have more rounded heads.
Pennsylvania's venomous snakes have slit-like pupils in their eyes, like cats' eyes, whereas, nonvenomous snakes have round pupils.
How to safely avoid an encounter with a timber rattlesnake.
Most rattlesnakes rattle when approached or if they feel threatened. If you hear rattling nearby, retreat and proceed by another route or proceed only after identifying its location. Do not attempt to displace or capture the snake.
Timber rattlesnakes are not an aggressive species and will avoid human contact if given the opportunity to flee or retreat under cover.
Never walk barefoot or with open shoes, like sandals, when hiking through Pennsylvania's wild lands.
Keep dogs leashed when hiking whenever practical. Be watchful of what they investigate especially when unleashed. While most dogs will avoid a rattlesnake, don't make any assumptions. A rattlesnake will strike if it feels threatened and is approached too closely.
Timber rattlesnakes may seek temporary shelter in outdoor man-made structures like wood piles, construction debris, etc. If one is found, realize that its occupancy is only temporary and that in few days it will move to another location.
What to do if bitten.
Never use ice, heat or a tourniquet near a venomous snake bite and never try to suck out the venom. Seek medical help immediately.
Timber rattlesnake facts.
The timber rattlesnake is the third largest venomous snake in the U.S.
The average adult male is approximately 42 to 46 inches long while adult females range from 34 to 38 inches in length.
Timber rattlesnakes can be brown, yellowish, grey or black in appearance.
John Best is a freelance writer. Find lehighvalleylive on Facebook.