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Canadian Herpetological Society





Société d'herpétologie du Canada



Hyla versicolor
Gray Treefrog / Rainette versicolore


Gray Treefrog

Description
The Gray Treefrog looks identical to Cope's Gray Treefrog. The two species can only be distinguished from each other by their calls. They have rough, green, brown or gray skin with large darker blotches on the back. Like many treefrogs, they have large toe-pads. The two species can be distinguished from other frogs by the dark-edged light spot under the eyes and by bright yellow-orange colouration under the thighs. Adults may reach 6 cm.

Call
The Gray Treefrog call is a short flutey trill. The call of Cope's Gray Treefrog is a faster, higher pitched trill. It is similar to that of the Eastern American Toad but is much shorter. It has more trill than that of a Wood Frog.

Confusing Species
Other treefrogs found in their range are the Spring Peeper, Boreal Chorus Frog, Western Chorus Frog and Blanchard's Cricket Frog. The Spring Peeper has a large, dark X on its back while the Chorus Frogs have three stripes down the back. Blanchard's Cricket Frog, limited only to Pelee Island in southern Ontario, has a dark triangle between the eyes and less distinct markings on the back than the other three species.

Distribution
In Canada, the Gray Treefrog occurs from southeastern Manitoba to New Brunswick. It overlaps with Cope's Gray Treefrog in eastern Manitoba and extreme western Ontario. It is also found in the easternhalf of the United States as far south as northern Florida and Texas.

Habitat
These treefrogs may be found on trees and shrubs near permanent water. They prefer mature or second growth woodlands although they may also inhabit orchards. They are rarely seen outside the breeding season.

Reproduction
Breeding occurs in late spring and early summer. During the day they remain in trees around the breeding pond. In the evening, males call from trees and shrubs but enter the pond after finding a mate. Up to 2000 eggs are laid in small clusters of 10-40 attached to vegetation. Eggs hatch within five days and tadpoles metamorphose 40 - 60 days after hatching.

Natural History
The Gray Treefrog is a tetraploid form of Cope's Gray Treefrog, which is to say that it is genetically the same but has four copies of each chromosome instead of the usual two copies. The Gray Treefrog is a true tree frog; it can be found at the top of even the tallest trees. Gray Treefrogs are sometimes found on the walls outside a building where there is a light that attracts insects. Gray Treefrogs overwinter under leaf litter and snow cover and can survive being frozen solid.

Conservation Concerns
Neither species is believed to be declining. Gray Treefrogs may be increasing in New Brunswick.