Cope's Gray Treefrog (Photo: Jeff Hall)
Scientific Names: Cope's Gray Treefrog-Hyla chrysoscelis
Northern Gray Treefrog-Hyla versicolor
Classification: Nongame species (Northern Gray Treefrog is a state-listed species of special concern)
Range: Cope's Gray Treefrog - Abundant (blue); Northern Gray Treefrog - Rare (documented only in Warren and Caswell counties)
Cope's gray treefrog (Photo by Jeff Hall)
Cope's gray treefrog-light colored (Photo by Jodie Owen)
Cope's gray treefrog (calling male) (Photo by Jodie Owen)
Both the Cope's gray treefrog and common gray treefrog call from April to August. Cope's gray treefrogs have a harsh, rapid trill; common gray treefroggs have a trill that is often slower and more melodic.
The Cope's gray treefrog and the northern (formerly called common) gray treefrog are identical in appearance. Both have somewhat rough, warty skin; a whitish spot under each eye; large toe pads; and bright orange or golden yellow on the underside of each hindleg. This bright orange or golden yellow coloring is believed to startle or confuse predators. In the laboratory, the two species can be distinguished by their chromosomes, with the common gray treefrog having twice as many as the Cope's gray treefrog. In the field, they can be distinguished by their breeding calls.
Cope's gray treefrogs are widespread throughout most of North Carolina. Northern gray treefrogs have been documented only in Warren and Caswell counties. Individuals of both species are capable of rapid color change; they may be gray, brown, greenish or nearly white. Their color-changing capabilities, along with their rough skin, provide these treefrogs with excellent camouflage when perched on tree branches or bark. Both species descend from the trees to breed in many types of ephemeral and permanent aquatic habitats. Eggs are laid at the water's surface in small masses of 30 or 40, usually attached to vegetation. Tadpoles transform in about 6 to 9 weeks.
The Cope's gray treefrog and northern gray treefrog are classified as a nongame species with no open season. It is unlawful for any person to take, or have in possession, any nongame mammal or bird unless that person has a collection license or is collecting fewer than 5 reptiles or fewer than 25 amphibians that are not endangered, threatened, or special concerned species. The northern gray treefrog is state listed as a species of special concern and cannot be taken except under a special permit issued by the Wildlife Commission's Executive Director. It is also listed in the N.C. Natural Heritage Program as Significantly Rare. More information
There are no reported problems with this species.
Frogs and toads can be monitored fairly easily in a variety of ways. One way is through frog call monitoring. The North Carolina Calling Amphibian Survey Program attempts to do just that by corralling data collected by volunteers across the state that monitors specific frog call routes. Each species of frog and toad has a unique call that is distinguishable from others. Some are more difficult for humans to separate than others, but the frogs know who’s who! Learn your frog calls, and you too can distinguish who’s calling in the ponds. Another way to monitor frogs and toads is by looking for egg masses deposited in wetlands and/or by looking for tadpoles in those same wetlands. Different frogs breed at different times of the year, so when to look for eggs is dependent on the species of interest. Eggs typically hatch within a couple weeks of being deposited, so there is a fairly short window for detection. Frog eggs can sometimes be identified to family, but are somewhat tricky to identify to species level. Tadpole identification can be similarly tricky, so learning and listening to frog calls is definitely the easiest method for determining what frogs and toads are using a wetland. Tadpoles are a little easier to monitor, as most species have tadpoles present in wetlands for longer periods of time. This is, again, variable by species. Most species have tadpole stages that last at least several months, but the range in timing for different species is everything from a couple of weeks to several years. The smaller frog and toad species tend to have shorter tadpole cycles, while the larger frogs and toads tend to have longer times to metamorphosis.
Wildlife Diversity Program Quarterly Reports
Protected Wildlife Species of North Carolina Listings (PDF)