Spring is sprung? Illinois' turtles convinced it’s true
Carbondale, Ill. — Skeptical of the warm days suggesting it’s time to pull the fishing gear out of hibernation? Figure a typical April snowstorm is bound to drive a stake through spring’s beating heart?
Then you might want to consult the state’s turtle population.
The sight of turtles lined up on a log, basking in the sun, is one of the earliest signs of true spring in Illinois, those who study turtles say.
And those signs came very early this year.
“A lot of turtles, the upper shell is usually dark, so it holds heat longer,” said Scott Ballard, a wildlife biologist with DNR. “A lot of times on days you’d think it would be too cold to see turtles, you’ll see the red-eared slider and the painted turtle basking on logs. Occasionally, there will be a big spiny softshell out there with them.”
Turtles experience true hibernation in this region.
“Some turtles will actually get down in the mud, as long as they can breathe,” Ballard said. “Some burrow into ponds or the banks of streams. Since they are probably closer to the surface, they probably feel the difference in surface temperature. That’s why you probably saw them on logs in February and March.”
While tanning isn’t particularly healthy for humans, it is beneficial for turtles.
“The vitamin D in sunshine helps to solidify their shells,” Ballard said. “That’s why you see turtles basking, because they need the vitamin D from the sunshine or they’ll get a soft shell.”
There are 17 species of turtles in Illinois, 14 in southern Illinois. The smallest turtle in the region is the musk turtle, averaging 3 to 4 inches. Turtles are measured by the length of the carapace.
The alligator snapper is the largest turtle in the region, but it is rarely seen. The common snapper can measure 12-14 inches.
Four species found in southern Illinois, the alligator snapper, ornate box turtle, river cooter and smooth softshell, are listed as state threatened or endangered. Ballard said degradation of habitat or dissection of habitat are the primary culprits.
Pet trade can also be harmful.
“A lot of box turtles have to be 18-19 years of age to be sexually mature,” he said. “Box turtles can live up to 100 years. You put a highway or a road through an area where they are real populous and at some point you are going to take out enough adults they won’t have a good breeding population any more.”
“The alligator snapper was never really common here,” he said. “They are found in backwater sloughs, Oakwood Bottoms, Big Muddy River and Clear Creek. They are extremely difficult to find unless they are female and come out of the water to lay eggs.”
Most turtles lay eggs in May.
“May is usually a real, real hazardous month for them because females are going up to laying sites,” Ballard said. “They hit the ag fields because it’s easier to dig a hole. And, some turtles do use asphalt surfaces for thermal regulating. That’s why you’ll see turtles along the roads.”
The early spring won’t cause early egg laying, Ballard said.