Wood frog (Rana sylvatica)

Among the many things that herald spring in Connecticut, one of our favorites is the "quork, quork, quork"
of wood frog males calling for mates. The wood frog has the ability to survive long cold winters by allowing part of its body to freeze. Specialized liver proteins and glucose prevent the inside of the cells from freezing and keep them hydrated while still allowing ice to form on the frog. At the same time, the wood frog’s breathing, heart rate and blood flow stops. In spring the wood frogs thaw and come back to life.<br><br>Our wood frog can be found in the Reptile House, which is located in the New England Farmyard. The wood frog does like to hide, so take a closer look. You may not know, but 2008 is the “Year of the Frog” at all AZA zoos and aquariums, including here at Connecticut’s Beardsley Zoo.


A medium sized frog ranging from 1.5 to 3 inches in length. The females are larger than the males. They can be varied in their colors, but for the most part they are tan, brown or rust colored. They also have a dark brown mask, which starts around the eyes and travels back to the base of their front limbs. The underside is usually yellowish, or sometimes greenish-white.


Mostly found in various woodlands, including forested swamps, ravines and bogs. During early spring they will breed in vernal pools.


Wood frogs range from northern Georgia north along the Appalachian Mountains through New England and north into Canada. They are also found throughout most of Canada and into Alaska. This is the only species of frog found north of the Arctic Circle.


The adults eat a wide variety of insects and invertebrates, including spiders, beetles, slugs, snails and caterpillars. The tadpoles mostly eat algae.

Life Span: 

Up to 3 years.

Family Life: 

The wood frog is the first frog to begin the breeding season in early spring, and sometimes they can be heard calling when there is still ice covering the vernal pools. The call of the wood frog sounds like a quacking duck. The calls are usually repeated and are only made during the breeding season. The tadpoles go through metamorphosis in about 2 months, and the new young frogs leave the vernal pools before the water dries up during the summer months. Many amphibians including the wood frog breed in vernal pools to avoid predation on the larvae. Since vernal pools dry up in the summer, fish and other predators that require permanent water cannot live in vernal pools, allowing the larvae of amphibians to survive.


Wood frogs are fairly common and are listed as least concern under IUCN. Habitat destruction, especially on vernal pools, may impact wood frog populations and the populations of other amphibian, especially the eastern spadefoot toad, which is an endangered species here in Connecticut. The Chytrid fungus is also a serious threat to wood frogs and all amphibians worldwide. This fungus infects the amphibians’ skin and leads to death.