It looked like an entirely ordinary spot in the suburban Maryland woods, a pile of oak leaves next to a small tree. But Chris Swarth knew a hibernating box turtle was down there, a few inches underground, waiting for spring.
Swarth is director of the Jug Bay Wetlands Sanctuary in Anne Arundel County, where nine species of turtles have been sighted, seven of them regularly. Three of the species there are being studied. One study tracks box turtles via small transmitters glued to their shells.
April marks the resurfacing of hibernating box turtles.
(Mark Gail -- The Washington Post)
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The box turtles dig down in November and stay underground for 5 1/2 months. With help from students, the sanctuary's small staff is monitoring soil temperature and the makeup of the leaf pile that the turtles bury themselves in. The workers want to answer basic questions about the box turtle's over-wintering behavior and to see whether it changes as the global climate warms.
Other turtles bury themselves in Jug Bay's marshy mud flats, swamps, ponds and river bottoms. Their metabolism slows and they barely need to breathe, which they do through their skin and anal opening ("a clever trick if you can learn it," Swarth jokes). Some painted turtles might emerge temporarily on a warm winter day, only to return to the muck as the temperatures drop.
April is when they come back up to feed and breed, and they are relatively easy to spot because most plants are not out yet. At Jug Bay, sometimes 75 painted turtles at a time can be seen basking in the sunlight, which helps give them energy.
Presumably, they rise up hungry. "If we weigh a turtle in October and again in April," Swarth said, "it's not unusual for it to be 5 percent lower in weight."
Most turtles are omnivores, eating everything from marsh plants to snails to fish. Snapping turtles also will eat small birds, reptiles and mammals. Red-bellied and painted turtles begin life as carnivores but later turn into plant-eaters.
Turtles also are commonly seen on a sunny day in such watery locations as the C&O Canal, marsh areas or storm ponds. But identifying which turtle you are seeing, especially if it is a smaller species, is not that simple.
Even Swarth has trouble distinguishing one species from another from a distance, especially if their shells are covered with mud. But he said they are "a fun animal to study." They are long-lived, so one can be followed for a long period. Some at Jug Bay have been tracked for a decade.
But the same slowness that helps scientists keep track of turtles also makes the animals susceptible to being run over by cars or picked up to become pets. Turtle scientists increasingly are alarmed about population losses in several species. They remain most concerned that open land where turtles live is diminishing because of development. They also are campaigning to urge people to leave turtles alone, to look but not touch, to admire from a distance.
Swarth has decided he needs to set an example. His visitor center has a box turtle on display in a small aquarium. He wants to put it back in the woods. In the future, he hopes to show only box turtles that have been so badly wounded that they might have trouble fending for themselves in nature.
Releasing turtles to the wild is not allowed without permission in most parks. Park officials do not want their areas to become dumping grounds for unwanted pets. And releasing turtles is not without risks. There might not be suitable mates nearby, or the newly freed turtle might have trouble figuring out how to make a living. But Swarth said that the risk is worth taking in this case and that it is important to show that an individual can do something to help turtles.
"We used to say that development was a worse threat," Swarth said. "Well, it's very hard to stop housing development, but it's not difficult not to have a pet. We need those turtles out in the world, doing their thing."
-- D'Vera Cohn
