Gray treefrog

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.

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 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. The bright patches are normally only visible while the frog is jumping. Both species of gray treefrogs are slightly sexually dimorphic. Males have black or gray throats, while the throats of the females are lighter. Tadpoles have rounded bodies (as opposed to the more elongated bodies of stream species) with high, wide tails that can be colored red if predators are in the system. Metamorphosis can occur as quickly as two months with optimal conditions. During metamorphosis, the new froglets will almost always turn green for a day or two before changing to the more common gray. Young frogs will also sometimes maintain a light green color, only turning gray or darker green once adulthood is reached. ==Distribution and habitat== The gray treefrog inhabits a wide geographic range, and can be found in most of the eastern half of the United States and as far west as central Texas and Oklahoma. It also ranges into Canada in the provinces of Quebec, Ontario, and Manitoba, with an isolated population in New Brunswick. The gray treefrog is capable of surviving freezing of its internal body fluids to temperatures as low as . However, when exposed to Batrachochytrium dendrobatidis, a fungal pathogen responsible for global amphibian declines, their critical temperature minimum increases, resulting in reduced cold tolerance and a greater possibility for overwintering mortality. The gray treefrog is most common in forested areas, as it is highly arboreal. Its calls are often heard in rural residential areas of the East Coast and the Midwest. It prefers to breed in semipermanent woodland ponds without fish, but it also lays eggs in swamps, vernal pools, man-made fountains and water gardens, and even in rainwater-filled swimming pool covers. ==Behavior== Male gray treefrogs rarely have large choruses, as they are mostly solitary animals, but might vocalize competitively at the height of breeding periods. The gray treefrog has been observed to congregate around windows and porch lights to eat insects that are attracted to the light. Insect larvae, mites, spiders, plant lice, harvestmen, and snails also contribute towards the diet of the gray treefrog. Some populations have a diet high in ants and beetles. However, like most frogs, Dryophytes versicolor is opportunistic and may also eat smaller frogs, including other treefrogs. There is a positive correlation between the mass of the frog's stomach contents and the distance from the pond: more beetles were found in the frog's stomach at increasing distances from the pond. During the day, it often rests on horizontal tree branches or leaves out in the open. The gray treefrog has also been observed to lie out in the direct sun. The gray tree frog is less prone to overheating and desiccation than other amphibians and relies on its camouflage to hide itself from predators. ==References== ==External links== Gray Treefrog – Hyla versicolor Species account from the Iowa Reptile and Amphibian Field Guide Gray Treefrog – Hyla versicolor – audio recording of call Tetraploid Gray Treefrog (Hyla versicolor), Natural Resources Canada Gray Treefrog Tadpole Tail Polymorphism, Images and explanation of tadpole tail coloration. Northern gray treefrog New Jersey Pinelands flora, fauna, and landscapes photo galleries link to northern gray treefrog photograph

Text derived from https://en.wikipedia.org/w/index.php?oldid=1373571001 under CC BY-SA 4.0; modifications have been made.