Cope's Gray Treefrogs - Hyla chrysoscelis

Common Gray Treefrogs - Hyla versicolor

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Hybrid "Gray" Treefrogs - Hyla chrysoscelis X Hyla avivoca


Although there are two separate species, they are often mistaken one for the other. Because of their amazing physical similarities, as well as that of habitat and range, the only way to distinguish between them in the field is by call. Hyla versicolor has a slow trill, while Hyla chrysoscelis has a faster, higher pitched trill. Hyla versicolor has twice the chromosome number of Hyla chrysoscelis. The Cope's X Bird-voiced hybrid has a call very similar to Hyla versicolor. The diagnostic features, natural history, and range listed below apply, for the most part, to both species.

May 25, 2008 - wwknapp@mindspring.com