When Justin Congdon was a teenager, he spent his days in the woods of northeastern Pennsylvania, shooting pheasants and trapping muskrats so he could sell their pelts for $4 apiece. He would have laughed had anyone told him he might spend the rest of his life in a forest preserve trapping turtles, X-raying their bellies, and painstakingly gluing their shells back together when they had the bad luck to be hit by cars.
But that’s precisely what he’s doing on this late May afternoon at the University of Michigan’s E. S. George Reserve, as he has done every spring and summer for 27 years. Carrying a leather tool belt with a makeshift rectal thermometer, needle-nose pliers, and black Sharpie pen, he patrols East Marsh, an 11.5-acre habitat with water lilies and wild irises. Most of the time he’s on the lookout for female turtles—Blanding’s, Common Snapping, and Midland Painted—abundant with fertilized eggs and ready to unload them on the first warm day. A low plastic fence separates the turtles’ marshland habitat from the higher, drier ground where they build their nests. For 16 hours Congdon circles the marsh, following the fence that keeps the turtles from escaping. Any gravid—pregnant—female that wants to leave the marsh must make a small contribution to science before she’s permitted to seek out a place to lay her eggs on the other side of the fence.
He spots a Midland Painted searching for a way past the barrier. She has the characteristic bright red trim around the edges o...