Yale Studies Wood Frogs in Vernal Pools

This spring, as you walk the beautiful trails of the Guilford Land Conservation Trust, be on the lookout for the many vernal ponds and red maple swamps that abound in these woods. They may appear small and insignificant; however these wetlands provide homes for a surprising number of amphibians, reptiles, and invertebrates.

While it may appear that you are surrounded by wilderness as you hike the GLCT trails, in reality, roads and residences are often quite close. A group of us from David Skelly’s lab at Yale University are currently studying amphibians that live in these suburban wetlands. Much of our work focuses on wood frogs (Rana sylvatica).

If you are out on a warm, early spring evening you may hear the male wood frogs wooing potential mates – their call sounds much like a mallard duck quacking. Once breeding ends, the adults head back to the woods, and the eggs are left to hatch into tadpoles. By July, wood frogs have completed the aquatic stage of their life cycle and have metamorphosed into tiny froglets. Our work focuses on wood frog tadpoles and their aquatic habitat.

Preliminary results from previous years’ work indicate that suburban habitats vary tremendously in forest cover, impervious surface, lawn and other land use categories and that this variation may affect sex ratios, behavior, and morphology of resident wood frogs. Given that land transformation for suburban use has increased tremendously over the past 50 years and shows no signs of slowing, an understanding of how this transformation impacts native species can inform our basic knowledge of species’ adaptability as well as provide critical information for conservation measures.

by Kealoha Freidenburg