Studying snakes where the suburbs meet the woods
By Julie Bierach, KWMU
St. Louis, MO – As new subdivisions spring up in formerly undeveloped wooded areas in West St. Louis County and Jefferson County, scientists at Washington University's Tyson Research Center are worried that snakes living there could be affected.
So, they've implanted dozens of rattlesnakes and copperheads with radio transmitters.
It's part of an effort to prevent a decline in the snake population and educate people that you can live and share the land with these creepy critters.
Washington University researcher Wayne Drda loves snakes: "I think they're really neat animals."
Drda's been researching them for about 40 years. He's the field manager for the Pitviper Research Project at Washington University's Tyson Research Center in Eureka, Missouri. The center is a wilderness area where his team and he study the basic movement patterns and habitat use of Timber rattlesnakes and Osage copperheads.
"A lot of the wildlife areas, especially in St. Louis County and Jefferson county are being surrounded by subdivisions and homes, and some are completely surrounded," Drda says. "So the animals tend to wander outside the wildlife areas into backyards and many of them don't survive that."
The Timber Rattlesnake has been eliminated from several states in the east and northeast. Drda and his team want to prevent that from happening in Missouri. He says snakes in general get a bad wrap. People don't like them so they become what he calls "nature vigilantes" and kill them.
"I guess the most common way is with a shovel. That's always the most common joke, the shovel," he quipped.
Drda and his team have implanted 26 snakes with the radio transmitters, and track them daily using a GPS system. "And basically we use that to map it on an area photo and determine how far the snake moved, where the snake moved, what kind of habitat they used, home range size," said student Ryan Turnquist.
On this particular day, they've already tracked eight snakes and are ontheir way to track another.
Drda says each snake has been named and assigned a frequency on the transmitter. The four-foot long male rattler he's tracking has been named Aron.
As he gets closer, the signal gets stronger. Turnquist leads the way pointing the big steel antenna in several directions.
And then, lying half coiled, near a log is Aron.
He's lying in the sun, but the black chevrons on his tan body allow him to blend in with the pile of leaves that surround him. He does not rattle, but instead is still, hoping not to be seen.
"This snake is probably in the most conspicuous situation you can find him in, except being out in the road," noted Drda. "And he's not going to give away his position by doing anything until he feels like he's really threatened.
"I mean he knows we're here, but he's probably not going to rattle."
As a matter of fact, Drda says they've already tracked some snakes that have made their way to residential propertie, and the owners don't even know it: "We've been trackin' this one snake, her name is Hortence. She's basically been in somebody's backyard now for three weeks I guess."
So far, the team has learned that the male timber rattlers have a large home range, breed in late summer, or early fall and don't breed with females from the same den they hibernate at.
Jeff Ettling, with the St. Louis Zoo, is conducting a DNA analysis to determine which corridors need to be kept open so the snakes can travel back and forth.
"If we can get enough samples within a given area, we should be able to tell what the relatedness is and which males are moving between dens," noted Ettling. "That's what we're hoping to find. We have a good idea by tracking them where they go. But which females are they breeding with from different dens we really don't have any idea right now."
Although the research team is finding new scientific information about the animals, they say the ultimate goal is to simply educate those that reside in the area that they can live with this species of rattlesnakes without destroying them.
Dr. Drda wants people who find a timber rattlesnake in their backyard to call a herpetologist, instead of going for the shovel.