HerpIndiana

Gray Treefrogs (Hyla chrysoscelis/versicolor)

Description

Coloration: A medium-sized treefrog with a mottled gray or green dorsal coloration. They have a distinctive yellow wash to the insides of the thighs. These treefrogs have a wide range of dorsal coloration, and the same individual can be light gray one day and green the next. Blotches with dark outlines make up the dorsal patterning. Gray Treefrogs have rougher skin than Green Treefrogs, the only other member of Hyla in Indiana. The Cope’s Gray Treefrog and Eastern Gray Treefrog cannot be distinguished morphologically (Minton 124-125). Juveniles looks similar to adults, though I have noticed that they tend to be green rather than gray.

Size: Gray Treefrogs grow to be about 1.5 inches in SV length (Minton 125).

Larvae: Tadpoles are small with heavy mottling on the tail; they often have a red or orange coloration on the tail as well (Conant 577).

Eggs: Eggs are laid in small clusters attached to vegetation, and transform in mid-late summer (Minton 127).

Distribution

These two species are distributed throughout Indiana, with Eastern Gray Treefrogs in the northern half and Cope’s Gray in the southern half. They meet near the center of the state and overlap somewhat (Minton 125).

Activity

This species spends a large amount of time concealed high in trees and is difficult to find outside of the breeding season.

Breeding Season: Gray Treefrogs begin calling in late April in some parts of the state and continue through July further north (Minton 126).

Taxonomy

Cope’s Gray Treefrogs Hyla chrysoscelisoccur in the southern half of the state. Eastern Gray Treefrogs Hyla versicolor occur in the northern half. This species belongs to the genus Hyla, which also includes Green Treefrogs Hyla cinerea in Indiana and is in the family Hylidae. The two species can only be separated by vocalization and chromosome differences.

Natural History

Habitat: Gray Treefrogs inhabit hardwood forests, and permanent water is not a necessity (Minton 125).

Feeding: This frog feeds on insects, probably mainly arboreal species (Minton 127).

Breeding: They breed from late April through July in swamps or ponds bordering their woodland habitat (Minton 125).

Call: The calls of these two species are the best way to conveniently tell them apart. Eastern Gray Treefrogs produce a slow trill, while that of the Cope’s Gray Treefrog is faster. In the field, these are often difficult to distinguish unless you have a reference (Conant 537).