The turtles, which can live at least 30-40 years and grow to almost the size of sewer manhole covers, are a good indicator species for the health of any river because they are found all over the United States, said McLane, 24, an Indianapolis native.
They also are vital to a river ecosystem because they eat fish and amphibians and scavenge on dead animal matter in the stream, he said.
“But we don't know much about them,” he added.
He and the faculty member supervising his study, biology professor Bruce Kingsbury, hope the data that McLane collects offers insight into the snappers' daily life and how they might be impacted by the dam just downstream at Johnny Appleseed Park.
Dams typically cause genetic breaks in a species, said Kingsbury, an expert on reptiles. While some animals from the species can go downstream, the ones downstream typically cannot migrate upstream over the dam.
McLane, who hopes to go into a career in conservation or wildlife management, started his project by getting approval from the Indiana Department of Natural Resources to catch snapping turtles and fit them with small radio transmitters.
He had placed special funnel-shaped nets in the river, with tuna fish as bait. The snappers could get into the net, but the funnel shape prevented them from swimming out. Plastic bottles filled with air kept the net above water so the turtles could come up for air, and he checked the nets twice a day so no turtle had to stay in very long.
McLane had hoped to catch five or six turtles below the dam to compare data with five or six from above the dam. He didn't catch any below the dam, however, so they started off with 11 snappers he caught above the dam.
“What we discovered is the dam does have an effect on where snapping turtles are,” Kingsbury said, noting they seem to prefer the quieter water above the dam.
The smallest weighs about 5 or 6 pounds and has a shell about the size of a small plate, McLane said. The largest weighs about 24 pounds and has a shell approaching the size of a manhole cover. He also made sure to get a mix of males and females in the study.
His study subjects let him know with sharp mouths wide open and lunges that they were none too happy about being disturbed from their usual routine.
He quickly took captured turtles to a work area on campus where he strapped their shells to the top of an upside-down wastebasket, leaving their legs flailing uselessly in the air. He then drilled two tiny holes on the back edge of each turtle's shell and used screws to attach a small radio transmitter, each with its own distinct radio signal frequency. The drilling didn't hurt the turtles, he said.
Then it was back to the river to send each snapper on its way.
McLane since has spent many hours this summer and early fall walking, wading, riding a bicycle and driving by car — always carrying a radio antenna and receiver — as he tries to tune in the beep, beep, beep that indicates the presence of one of the turtles.
He typically starts by the Venderly Family Bridge on the west side of the IPFW campus. He sets the radio receiver to one turtle's signal frequency, and then sweeps slowly across the area with the antenna to see if he can pick up a signal. He runs through the entire list of signal frequencies before moving downstream or upstream.
By triangulating the signal from different nearby locations, he can determine fairly closely the location of the turtle, and then enters the information into a hand-held GPS unit dangling from a lanyard around his neck. Sometimes locating a turtle involves crossing to the west side of the river, or driving north until he finds it upstream.
“It seems one of my turtles traveled up to St. Joe Center Road,” a distance of about 1.5 miles, he said.
He discovered another one went over the dam, and has stayed just below the dam since the first week of tracking.
Most of the turtles usually stay around the wide expanse of river around the Venderly bridge, McLane said. That could be because a peninsula juts out into the river there, creating a shallow area that then drops off to deep water and also a quiet, shallow lagoon back to its west.
“I know this one has spent the entire summer in this area,” he said of Turtle No. 2, one of the smaller snappers, whose transmitter's beep, beep, beep came across his receiver last Friday just north of the Venderly bridge. It was the 38th time he had picked up its signal.
McLane, who is scheduled to complete his graduate degree by next fall, enters his tracking data in a computer program that allows him to plot their locations in the river and to record and analyze a range of other information.
Eventually, he and Kingsbury hope to make the data available on the World Wide Web for use by area students doing research reports or projects on rivers, turtles or related topics.
McLane also is looking forward to following the turtles this winter.
Do they slip into a suspended state like hibernation, or do they continue moving about and foraging for food?
“It will be interesting to see what they do,” he said.
Helping community, environmentIPFW faculty and students do research in a wide range of fields, and some of those experts and researchers plan to share their data and expertise through the Environmental Resources Center (ERC) at the university.
Established in July 2012, the center has kept a low profile while getting up and running, said Bruce Kingsbury, a professor of biology and the ERC director.
Kingsbury, an expert on reptiles, hopes the ERC will promote collaboration on environmental projects, both among IPFW faculty and through IPFW faculty and students working with partners in the community.
IPFW students benefit because it provides more opportunities for hands-on research, he said. The community and organizations will benefit from advice from IPFW experts and from data collected by faculty and students during their research.
With efforts to create increased use of Fort Wayne's rivers, Kingsbury said faculty affiliated with the ERC could help the city think about what questions need to be asked or what answers need to be obtained before moving forward.
“If you look at the river in town and in some farm fields, it is being treated as a ditch,” Kingsbury said.
In many places around the Midwest, people also have taken the same approach with the headwaters of streams, said Robert Gillespie, an associate professor of biology at IPFW and one of the faculty members involved in the ERC. Gillespie specializes in research on aquatic life, water bodies and factors impacting them.
Along with helping government and community organizations, the ERC also plans to make research data available to students of all grade levels to assist them with their learning, Kingsbury said.
For more about the ERC, go to http://erc.ipfw.edu or on Facebook at https://www.facebook.com/IpfwEnvironmentalResourcesCenter.