GATLINBURG, Tenn. — At Twin Creeks in the Great Smoky Mountains, try not to jump if you're suddenly surrounded by the sound of hundreds of turkeys. It is likely the call of frogs gone wild on a warm winter day.
"Some people say they sound like turkeys. Some people say ducks. Some kind of bird. But those are wood frogs, a really cool species of frog you start to hear calling around this time of year. What you're hearing is the males calling for the females. It goes on for the next month-and-a-half to two months," said Phil Colclough, Zoo Knoxville's director of animal care, conservation and education.
Colclough said for the frogs to engage in the winter season of love, they may literally have to thaw their hearts.
"Wood frogs are really adept at surviving super-cold temperatures. They are the species that can freeze almost solid and survive through the winter. They can freeze 65 percent of their bodies and their hearts stop completely. Their livers pump their bodies with glucose that acts like antifreeze to prevent the cold from damaging cells. When it warms up, they reanimate and go about their business. My guess is some of these frogs [breeding today] may have been frozen three weeks ago," said Colclough.
When the days begin growing longer, thawed wood frogs will seize on any warm stretch to turn ponds, swamps, and ditches into spawn shops to fertilize as many eggs as they can. One female wood frog can lay up to 1,000 eggs.
"The female produces eggs and the males will fertilize them externally," said Colclough.
Everyone should care about frogs, according to Colclough. He said a large population of the amphibians indicates a healthy environment.
"Frogs are a bioindicator species. They are kind of like a canary in the coal mine, if you will. They kind of indicate the health of an environment. They are very sensitive to environmental pollutants," said Colclough.
The mass of eggs that fill the water and survive will transform into tadpoles and eventually wood frogs. The time from egg to wood frog can be as short as seven weeks. But Colclough said frogs can postpone their metamorphosis until conditions are right, sometimes remaining tadpoles for up to a year.
The eggs fertilized by the current crop of frisky frogs will likely transform in March. Appropriately enough, this February has an extra day for leap year.
You can set out to go frog-watching in the heavily-protected environment in the Smokies, but they can show up anywhere in East Tennessee. Just be discrete because they get tongue-tied if you get too close.
"They're going to be quiet as soon as you get near them. So, you don't necessarily have to see them to enjoy them," said Colclough. "You can just enjoy observing them with your ears, a lot of times in your back yard. I get my whole family out on the back porch and say, 'Hey, listen!' What are we hearing, dad? 'The frogs. They are here. It is time!'"
Whenever and wherever you come across them, enjoy the performance by these amphibious hopera singers. They're just a cold snap away from another intermission as a frozen frog-sickle.
"Then they reanimate in the spring and go out and do their business. Listening to them, that's my favorite springtime sound," said Colclough.
Zoo Knoxville's mission of conservation and education includes participation and promotion of citizen science programs. The projects include Frog Watch USA through the Association of Zoos and Aquariums.
"People can actually report frog populations directly to the website and monitor where frogs are healthy or not," said Colclough.