The Way Home
For somebody who studies something so slow, it’s hard to keep up with Dr. Aaron Krochmal. The assistant professor of biology is so passionate about the behavioral, physiological, and evolutionary ecology of critters (reptiles, specifically), so effusive about the value of experiential learning, that a talk about his study of Eastern painted turtles takes listeners on a cosmic global journey from far Eastern mythology to a Maryland mudflat, just like that. By the time you finish riding the entertaining wave of his science, you’re ready to follow him through the muck and briar, listening for the telltale beeping that means there’s a radio-tagged turtle on the move.
And it’s these animals’ travels that have provoked the study, now in its third year, examining how turtles manage to find—or not—new habitats when their home pond is suddenly more mud than water. Scientists have spent gobs of time studying migratory species, Krochmal says, “but little is known about how aquatic turtles move across land, largely because we don’t know when they’ll start!” Krochmal realized that a waterfowl management pond at DuPont’s Chesapeake Farms was the ideal starting point, “because when the pond is annually drained, we know the precise moment these animals will take to land in search of a new aquatic home.”
By radio-tagging, tracking, and mapping different turtle populations, Krochmal and his students have made some interesting discoveries about these humble, ecologically critical animals. Most significantly, they’ve learned that while adult and juvenile resident turtles can, within about 24 hours, travel seemingly established routes to a distant pond, adult non-residents can’t find their way out of a paper bag. The juvenile non-residents can do it, but the adults seem to travel aimlessly, losing, in their wanderings, as much as 40 percent of their body mass. This has bearing on the conservation management technique of moving populations when their homes are compromised. “Translocation might not be the solution to conserving turtle species,” Krochmal says. “Turtles seem to need juvenile experience in a pond to make it its home.”