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Checklist of Amphibian Species and Identification Guide

Gray Treefrog, Hyla versicolor
Cope's Gray Treefrog, Hyla chrysoscelis


gray treefrog color morphs of gray treefrog

The Gray Treefrog (Hyla versicolor) and Cope's Gray Treefrog (Hyla chrysoscelis) were once thought to be the same species. They cannot be distinguished from one another by external appearance. They can be differentiated in the field by their calls, and in the laboratory by their chromosome number: H. chrysoscelis is diploid, having two pairs of every chromosome, while H. versicolor is tetraploid, having 4 copies of every chromosome. Data suggests that the tetraploid species evolved from the diploid through chromosomal mutation, in this case a doubling of the number of chromosomes (polyploidy). It is believed that this has happened on several occasions independently of each other in different parts of H. chrysoscelis' range. The range map and discussion below applies to both species which are collectively referred to as Gray Treefrogs. Note, however, that both species do not occur uniformly throughout the range showed, there are regions where only one of them is found.

Gray Treefrogs are small to medium sized frogs reaching lengths of about 2 inches. An individual frog can be gray or green, as shown here, or various shades of brown or even nearly white. Which color depends in part on the frog's immediate environment and its activity. Some Gray Treefrogs may have well defined markings on the back or they may also be a solid color without the dark markings. Solid colors, usually green, are most likely to occur during the breeding period. They commonly have a white rectangular spot under the eye, and can be confused with the Bird-voiced Treefrog (see that species for tips on how tho tell them apart from Gray Treefrogs). The treefrogs are also characterized by having large discs on the ends of their digits allowing them to cling to vertical surfaces. Outside of the breeding eason they spend much of their time in trees, making it difficult to find them.

A green Gray Treefrog Composite Gray Tree Frog Range
Gray Treefrog Tadpole ventral view of treefrog
This is a ventral view of both the male and female. Note the black surface under the jaw of the male. This indicates the presence of the vocal sac used during calling. Tadpoles of Gray Treefrogs often have reddish tails mottled with dark pigment.

More photos of Gray Treefrogs (Hyla chrysoscelis & H. versicolor).

Gray Treefrog Gray Treefrog Gray Treefrog
Gray Treefrog Gray Treefrog Gray Treefrog

Notice:  All images contained hereafter are the property of the said photographer. They are not to be reproduced, copied, printed, stored, or distributed without written permission of the photographer.

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