Gray treefrog

## Description

The gray treefrog (Dryophytes versicolor ) is a species of small arboreal holarctic tree frog native to much of the eastern United States and southeastern Canada.

It is sometimes referred to as the eastern gray treefrog, northern gray treefrog, common gray treefrog, or tetraploid gray treefrog to distinguish it from its more southern, genetically disparate relative, Cope's gray treefrog.

## Appearance

The eastern gray treefrog measures 1.25 to 2 inches (3-5cm) in length. The record length is 2.25 in. (6 cm). There is no sexual dimorphism. The dorsal surface of the gray treefrog species is rough and lightly sprinkled with warts,more than most frogs but less than the average toad. The large toepads produce mucous to adhere to smooth bark or man-made structures near light sources, and are characteristic of the family Hylidae. The colors of a gray treefrog vary with the colors of its background and environmental factors such as season and humidity, but shades of gray are most common with black blotches on the back. Variations of brown, green, and pearl-gray colors have been noted. Green colors are more prominent during the breeding season and in yearling frogs. Usually, there is a white mark beneath the eye. The ventral skin on the hind legs, in the groin region, may appear orange to golden yellow with black speckles and the belly is white.

If the coloration is in question, place the treefrog in a box, allow it to sit quietly, and later re-examine the specimen. The yearling frogs are about half the size of the older H. versicolor population, but retain the same characteristics. Gray treefrogs continue to grow each year until they achieve the physical limit of the species.

Both gray treefrog species possess the same larval traits, but H. versicolor was used to exemplify the tadpole stage in Conant and Collins' "A Field Guide to Reptiles and Amphibians of East Central North America". The tadpoles are small, but colorful, 1.25 in. to 1.5 in. (3.2 cm. to 3.8 cm.) long. The tip of the tail is well-defined with a 5 mm narrow tip. The oral disc is comprised of 2 upper labial tooth rows and 3 lower, serrated jaws, and an overhanging upper jaw. The intestinal coil is also visible. The background color is light green to yellow. The tallest section of the tail fin is the middle and heavy black dots are scattered along the margin on a red or orange background across the tail.

## Distribution

Both gray treefrog species, Hyla versicolor and Hyla chrysoscelis, inhabit a wide range from southern Ontario and Maine, westward to central Texas, northwest to Manitoba, and northern Florida. An isolated colony is also noted in New Brunswick. The two species appear physically identical, and consequently more studies are necessary to delineate where the species overlap.

Generally, the eastern gray treefrog (H. versicolor) is mostly found to the north and northeast of the range. However, the gray treefrog species are extremely variable in their distribution pattern. For instance, the eastern gray treefrog is common in the eastern Great Lakes region, including southern Michigan; however, both species: H. versicolor and H. chrysoscelis share the same breeding ponds in Wisconsin and northern Michigan.

Eastern gray Treefrogs inhabit all elevations of wooded areas near temporary and permanent waters in such diverse surroundings such as swamps, ponds, lakes, old fields, thickly wooded suburban neighborhoods, farm woodlots, and mixed or deciduous forests. During the summer months, they are most often found in damp rotten logs or hollow trees. In winter, gray treefrogs hibernate on land under woody debris such as logs, roots and leaf litter.

## Behavior

Male gray treefrogs rarely have large choruses, as they are mostly solitary animals, but might vocalize competitively at the height of breeding periods. Gray treefrogs may congregate around windows and porch lights to eat insects that are attracted to the light. During the day they often rest on horizontal tree branches or leaves out in the open, even in the sun. Evidently they are less prone to overheating and desiccation than other amphibians and rely on their superb camouflage to hide them from predators.

## Diet

As tadpoles, eastern gray treefrogs begin life by grazing on algae and detritus in their pond.

After metamorphosis, H. versicolor prey upon most types of insects and their larvae. Mites, spiders, plant lice, harvestmen, and snails are also eaten. Gray treefrogs mostly hunt insects in the understory of wooded areas in small trees and shrubs, where they may rely upon their camouflage with less risk of predation. However, like most frogs, H. versicolor is opportunitistic and may also eat smaller frogs, including other tree frogs.

## Reproduction

Mating calls and chorusing are most frequent at night, but individuals often call during daytime in response to thunder or other loud noises. Males produce advertisement calls for females as well as aggressive calls to counter other males. Females are able to discriminate between these.