Rainette versicolore— Quebec wildlife

The gray treefrog (Dryophytes versicolor) is a species of small arboreal frog in the family Hylidae. The species is native to much of the eastern United States and southeastern Canada. It is sometimes referred to as the eastern gray treefrog, northern gray treefrog, common gray treefrog, or tetraploid gray treefrog to distinguish it from its more southern, genetically distinct relative, Cope's gray treefrog.

Description

As the specific name versicolor implies, the gray treefrog is variable in color. This ability to vary its color provides it with the ability to camouflage itself from gray to green or brown, depending on the environment around it. Dryophytes versicolor can change from nearly black to nearly white. It changes color at a slower rate than a chameleon. A unique aspect of the appearance of the gray treefrog is that its legs feature a dark band-like pattern which then contrast sharply with the black-marked bright yellow or orange under the sides of its legs and arms. Dead gray treefrogs and ones in unnatural surroundings are predominantly gray. The female does not call; however, the male does call. The female gray treefrog is usually larger than its male counterpart. The gray treefrog is relatively small compared to other North American frog species, typically attaining no more than 1.5 to 2 in (3.8 to 5.1 cm) in snout-to-vent length (SVL). The skin has a lumpy texture to it, giving it a warty appearance. This species is virtually indistinguishable from Cope's gray treefrog, the only readily noticeable difference being that Cope's gray treefrog has a shorter, faster call. This varies depending on the temperature, however, as the call rates of both gray treefrogs are temperature dependent. At lower temperatures, Cope's gray treefrog can have a call rate approximating that of the gray treefrog. This difference in calling can be heard, but it is best quantified by counting the number of pulses per second in their whistled trills. At usual temperatures, the gray treefrog has a pulse rate of 16 to 34 pulses per second, while Cope's gray treefrog has a pulse rate of 34 to 60 pulses per second. Even though there is potential for overlap, because of the temperature dependence of the pulse frequency the two species are easily distinguished where they occur together. At a given temperature, the pulse frequency for the gray treefrog is approximately one-half that of Cope's gray treefrog. The gray treefrog has 48 chromosomes (4n), and is sometimes referred to as the tetraploid gray treefrog in scientific literature. Cope's gray treefrog, or the diploid gray treefrog, retained its 2n (24) original chromosome count. Hybridization between these species results in early mortality of many larvae. Some individuals survive to adulthood, but these individuals suffer from reduced fertility. Both of these similar species have bright-yellow patches on their hind legs, which distinguishes them from other treefrogs, such as the bird-voiced tree frog.