Tracking turtles and habitat use: Study in Cook County

Road-kill turtles benefiting research on habitat for turtles is working in Cook County in an around-about way.

Fourteen turtles–six common snappers, five southern painted and three red-eared sliders–were fitted with radio transmitters on Sept. 16, then released back from where they came in an ongoing cooperative research project with the Forest Preserves of Cook County and Friends of the Chicago River.

The turtles were trapped around Thorn Creek near Wampum Lake, then transported to the FPCC’s McGinnis Field Station in Orland Park.

There they were aged by measuring. That’s where the road-kill comes in, which I found interesting.

Chris Anchor, FPCC’s senior wildlife biologist, has had a project going for decades to age road-killed turtles.

He said there’s data going back far enough to age five of the seven turtles in the Chicago area–snappers, painted, softshell, red-ear, stinkpot (common musk turtle)–by measuring the carapace, the upper portion of the shell.

The first turtle was a painted, with its carapace measuring 16..9 mm by 12.1. After measuring, a blood sample was taken.

“They are so long-lived, they can act as barometers,’’ Anchor said.

Then a PIT tag (tiny electronic tag) was attached. Then came the attaching of the radio transmitter, which Anchor said, “Tells us what areas they are utilizing.’’

The radio frequency was set. Then the best spot–each turtle’s carapace is different–was found to paste the transmitter.

That spot on the carapace was wiped clean, then brushed hard with a wire pipe-cleaner brush. Only then was the transmitter affixed with a water-resistant, quick-setting epoxy. Afterward, it needed to be held for three to five minutes for the transmitter to stick.

It was amusing to see Anchor, Friends’ executive director Margaret Frisbie and Claire Snyder, conservation programs specialist for Friends, standing around McGinnis Field Station with a turtle clamped between their fingers for five minutes.

The object of this study is to find out more about turtle habitat and how it is used in Cook County. The Cook part matters because it has the highest density of predators in Illinois. That means eggs surviving from being buried to hatched is tough.

One of the ways to help survival is to improve habitat by controlling brush and burning the site, which opens up space for turtles.

Frisbie said there is already some evidence of turtles utilizing improved habitat in the north suburbs. She said they were funded for three years through a grant to study turtle habitat, osprey platforms and bat maternity colonies.

Anchor said before they haven’t been able to “synchronize with land management, but with this cooperation, all the planets aligned.’’ He expects they will find out what turtles do in laying eggs and what they utilize.

Finally, John Hartmann, USDA wildlife biologist, and Hannah O’Malley, USDA wildlife specialist, lifted up the big boy snapper, which Anchor estimated was about 30-years-old. They carefully did all the paper work.

After it was fitted with a transmitter, Steve Silic, FPCC’s fisheries biologist, improvised and held the big boy on the slats of a wooden pallet to hold the transmitter in place until it set.

I stood by to document in case the snapper whipped free and took one of Silic’s digits. But all went smoothly.

The final step was a caravan of turtles to release back in Thorn Creek.

There Snyder climbed into the creek, then Anchor handed turtles down.

“Thanks for letting me do this, it was awesome.” Snyder said.

The turtles lumbered off into the water, transmitters looking odd.