Eastern Gray Treefrog (Hyla versicolor)
Description: Eastern Gray Treefrogs can be gray with darker blotches or green with darker blotches (see above pictures). Their belly is usually cream or whitish. The toes of Eastern Gray Treefrogs are only partially webbed and tipped with obvious toe pads or "suction cups" (see above pictures). They are small to medium sized frogs (1 to 2" snout to rum length). Eastern Gray Treefrogs are members of the family Hylidae, which includes most treefrogs worldwide. Within Wisconsin, they are most closely related to Cope's Gray Treefrog, with whom they share the same genus (Hyla).
Habitat/Ecology: Eastern Gray Treefrogs prefer vegetated habitats with ponds or marshes close by. They can be found in areas that have been disturbed by humans as long as there is ample vegetation available for them to hide in. In fact, I have witnessed them several times on the kitchen window of my grandmothers' house or next to the porch light on my parents' patio (neither location in La Crosse County). Eastern Gray Treefrogs spend most of their time under wet organic debris, except during the breeding season, when they come out into the open to mate. These frogs eat many insects, worms, and slugs (among other invertebrates).
Remarks: Male Eastern Gray Treefrogs call from mid-May through late June. Their call is a high-pitched trill that may sound similar to the American Toad or the Cope's Gray Treefrog, however, it is not as long in duration as the American Toad's and is more melodic than the Cope's. In addition, Eastern Gray Treefrogs, genetically, are tetraploids, and they have double the chromosomes (48) of Cope's Gray Treefrogs (24), which are diploid. Eastern Gray Treefrogs, like many treefrogs, can climb and cling to sheer surfaces. They are sometimes seen on walls or windows at night near house lights. They are found near these lights because they attract insects (such as moths and mosquitoes) which the frogs feed on. Like Chorus and Wood Frogs, Gray Treefrogs can survive partial freezing during winter hibernation due to a special "anti-freeze" produced by their cells.
I have heard Eastern Gray Treefrogs calling at several locations throughout La Crosse, including the La Crosse River Marsh (Myrick Park Marsh) and the Goose Island area. While driving country roads at night during June, raucous choruses of these frogs can be heard emanating from many places across the landscape, including farm ponds, marshes, and backwater sloughs.