Gray Tree Frog

The **gray treefrog** (*Hyla versicolor*) is a species of small arboreal frog native to much of the eastern United States and southeastern Canada. It is sometimes referred to as the **eastern gray treefrog**, **common gray treefrog**, or **tetraploid gray treefrog** to distinguish it from its more southern, genetically disparate relative, the Cope's gray treefrog (*Hyla chrysoscelis*). It may sometimes be referred to as the **North American treefrog** by Europeans to distinguish it from their European treefrog (*Hyla arborea*).

## Characteristics

The gray treefrog is about two inches in length. It is green, gray, or brown in color. It can be a solid color, or it can have blotches on its back. The gray treefrog can change its color in seconds. It tends to become darker when it is cold or dark. Its coloring helps it blend in with tree bark!  It has a white underside and lots of warts. It has large, sticky toe pads that help it cling to tree bark and other surfaces. It has bright yellow to orange skin under its thighs. There is another species of tree frog, Cope's gray treefrog, that looks exactly like the gray treefrog. You can tell them apart by their calls. The gray treefrog's call has a slower trill that is more musical the the Cope's treefrog's call. The gray treefrog is also a little larger than the Cope's gray treefrog; and it has bumpier skin. Scientists can tell the difference between the two species because the gray treefrog has twice as many chromosomes as Cope's gray treefrogs.

## Range and Habitat

The gray treefrog is found from Manitoba east to Maine and south to northern Florida and central Texas. The gray treefrog is found in New Hampshire. The gray treefrog lives in moist, deciduous woodlands and swamps near water. It is also found in pine barrens.

## Diet

The gray treefrog finds its food in the trees and shrubs. It eats moths, tree crickets, ants, flies, grasshoppers and beetles. It is very acrobatic and will often jump from branch to branch to catch its prey.

## Life Cycle

Breeding season runs from April to August. Males will gather in trees and bushes next to breeding ponds and swamps and begin calling. The male will aggressively defend its territory from intruders. The female selects a mate based on its call. She lays her eggs on the surface of shallow water in ponds or swamps. She may also lay her eggs in standing water in tire ruts, vernal pools or even swimming pools. The eggs are attached to vegetation to keep them from floating away. The female lays as many as 2000 eggs in groups of 10-40. The tadpoles hatch in four or five days and will change into froglets in about two months.

## Behavior

The gray treefrog is nocturnal. It spends the day resting in trees and shrubs. At night it crawls among the branches and leaves looking for food. It usually only comes out of the trees and bushes during breeding season and in the winter. It hibernates under leaves, bark or rocks on the forest floor. It actually freezes in the winter! The green treefrog produces large amounts of  glycerol. The glycerol is changed to glucose and then it is circulated through the frog's cells. The glucose acts like kind of antifreeze and prevents ice crystals from forming in the cells. If ice crystals formed in the cells, they would rip the cells apart and kill the frog. The rest of the water and blood in the frogs body then freezes and its heartbeat and breathing stop. When the temperature warms up, the treefrog "thaws out" and returns to the trees.