JUNIATA SCIENCE TEAM HATCHES RESEARCH ON TURTLE NESTING
(Posted March 29, 2001)
Asking why turtles try to cross the newly constructed Route 522 highway bypass in Mount Union seems like the setup to an obscure joke, but thanks to research by a team of Juniata College scientists, in collaboration with the Pennsylvania Department of Transportation, hundreds of turtles are being saved from a fate as roadkill. In addition, wildlife scientists are learning much more about the habits of map turtles.
"The new 522 bypass at Mount Union opened in 1998, and in the spring of 1999, hundreds of map turtles came out of the Juniata River to lay eggs in their nesting ground -- which is now part of the new highway," says Roy Nagle, manager of Juniata's Brumbaugh Science Center and an adjunct lecturer in environmental science. "The new bypass had been built on a huge pile of coal slag and the turtles had been using this area as their nesting site."
Map turtles are large, river-dwelling reptiles about the size of a dinner plate. Although there are about 12 species of map turtles that range from southern states to Canada, one of the few map turtle populations found in Pennsylvania is within the Susquehanna River drainage, a watershed system that includes the Juniata River. Nagle says the Pennsylvania species is not considered endangered.
Nagle estimates that between 50 to 100 map turtles were killed by traffic before PennDOT spent nearly $60,000 in 2000 to install a low chain-link fence between the Juniata River and the highway. The transportation agency also installed about 80 tons of sand donated by U.S. Silica, a Mapleton-based company, to create a series of possible nesting sites along the fence line.
PennDOT and Juniata also hired students to monitor the area during the spring and summer of 2000. Juniata students Clayton Lutz, a junior from Altoona, and Tim Enedy, a senior from Portage, spent the year observing and monitoring the map turtle nesting site. Another student, Vince Eilenberger, a Grove City College senior from Altoona, worked alongside the Juniata students.
Juniata College and PennDOT District 9 recently received the 2001 Pennsylvania Quality Initiative Environmental Award, which is given to organizations involved in outstanding transportation projects in Pennsylvania, for their work on the turtle project.
Among the research done last year by Nagle and his team:
--The team installed radio transmitters on three female turtles to track how large a range the turtles use for their habitat. Two of the turtles wearing transmitters stayed within four miles of the nesting site and one returned to the Mount Union site. The third turtle apparently traveled out of radio range.
--Deaths of turtles on the 522 highway were reduced from 50 to 100 in 1999 to just 10 in 2000. Almost all the turtles killed in 2000 were killed in an area beyond the chain-link fencing north of the protected nesting area. "We recommended that 300 more meters of fence be installed at that northern site," Nagle says.
--The student researchers observed that young map turtles stay in their hidden nests nearly eight months after hatching
--Thirty-three known nests were protected by wire-mesh cages supplied by PennDOT. The researchers found 50 nests in all. The cages were small enough to keep raccoons and other animals away from the nests, yet large enough to let small turtles out.
--The researchers captured 254 turtles of four different species. More than 95 percent of the captures were map turtles.
--Map turtles may prefer darker soil or material to make nests. Many turtles did not make nests in the sand supplied as nesting material. "The turtles may prefer darker material because it provides warmer incubation temperatures, or the replacement sand may have been in the wrong place or it could have been the wrong color," Nagle says. "The dark-color coal slag, which had been dumped on this site in the 19th century, may have been a map turtle nesting site for more than 100 years."
The team's research indicates that map turtles used this stretch of the Juniata River as a nesting site because the coal slag heap provided perfect nesting habitat. "Map turtles prefer nesting sites that are easy to dig and that drain well," Nagle says. "The nests must be exposed to the sun as well, because the young will not develop if the temperature is not warm enough. The coal slag apparently fit all their criteria."
Lutz, who will repeat his research assignment at the site this summer, says working on such a large project as an undergraduate student is a once-in-a-lifetime opportunity.
From May to July 30, 2000 the students patrolled the area from 7:30 a.m. to 4:30 p.m. during weekdays. They observed nesting turtles, recorded any roadkill deaths or any turtle nests destroyed by predators, and recorded data on any turtle they captured. The students measured each turtle, recorded the turtle's temperature, marked all the turtles they captured and gave any female adult turtle a unique identification mark using a paint pen.
"Map turtles are probably one of the most understudied turtles in North America in terms of nesting and reproduction, probably because of their limited distribution," Nagle explains. "Juniata's partnership with PennDOT has given us the opportunity to collect basic ecological data and apply it to a local conservation issue."
Contact John Wall at firstname.lastname@example.org or (814) 641-3132 for more information.