NBS Blog

Froggie Went a Courtin’

Dearest nature-fiend, 

Are you feeling jumpy to find out what spring is doing to the wild?! At Norman Bird Sanctuary, we love to celebrate the signs of spring across our campus! 

If you walk along Nelson Pond Trail in March, perhaps around Saint Patrick’s Day, you may hear a mysterious, duck-like quacking sound when no ducks are in sight. The culprit of this chorus is the wood frog, Lithobates sylvaticus. Its genus, Lithobates, means “one who walks on stones”, while its species name, sylvaticus, means “woods-dweller”. Male Wood Frogs spend their brief mating season quacking it up, reeling in all the lady frogs with their duckiness.

While you and I are garbed in wool sweaters and playing in the snow, Wood Frogs spend their winter under leaf litter, in the top layer of soil, experiencing a special type of hibernation called “brumation”. Brumation is to amphibians as hibernation is to mammals! Up to 65 percent of the water in a wood frog’s body may freeze in the coldest weather, but glucose in key organs acts as an antifreeze to keep ice crystals from forming there. In this state, wood frogs may even stop breathing and put their heart beat on pause. Talk about being chilled to the bone!

When the weather warms, the wood frogs thaw and resume their normal functions. You’ll hear the males quacking calls, the first sign that the frogs are up, and breeding season is a-go. If you hear a quack but see no duck, you might imagine this miraculous feat is going on: While wood frogs live solitary lives outside of the breeding season, when the two sexes come together, females can lay up to 3000 eggs in vernal pools and shallow bodies of water.

Now my froggy friend, please take my advice to heart. The wondrous wood frog will lure you in with its sweet chorus, but these creatures are extremely sensitive to human presence. As you approach, the frogs will fall silent and swim off to safety. If you do get to see one of these masked beauties, consider yourself lucky!