Gray Tree Frog

The gray tree frog is a large species of tree frog that can take on many colors despite its name. It is commonly found in southeastern Canada and the eastern United States. The gray tree frog spends most of its life high up among the trees and is very adept at navigating the branches thanks to its sticky feet.

4 Incredible Gray Tree Frog Facts

• This tree frog varies its color to match its environment, such as being darker to match tree bark.
• The grey tree frog slows down its metabolic processes in the winter and essentially freezes until spring.
• These frogs are an essential part of its ecological niche.
• They secrete a slightly poisonous toxin from their skin.

Scientific Name

The gray tree frog’s scientific name is Hyla versicolor, which is derived from the Latin for “variable color” due to its ability to alter the color of its skin based on certain factors, such as being a lighter shade at night and a darker tone during the day. It belongs to the Hylidae Family and Amphibia Class.

Other common names for the gray tree frog are the eastern gray treefrog, northern gray treefrog, common gray treefrog, and tetraploid gray treefrog.

Evolution and History

Genetic studies have shown that the gray tree frog evolved due to “multiple hybrid events” involving ancestors that have two sets of chromosomes. The species has been found to have DNA from Cope’s gray tree frog (H. chrysoscelis) and two other species that are now extinct but most likely were present in the northeastern and northwestern parts of the gray tree frog’s range.

These frogs are almost indistinguishable from the Cope’s gray tree frog. The Cope’s gray tree frog has the same appearance as the gray tree frog and can only be identified by a slightly slower call. They are otherwise completely separate species, with the gray tree frog having twice as many chromosomes as the Cope’s gray tree frog.

It’s uncertain how the gray tree frog evolved to be able to change color. Although it may seem like a chameleon in its abilities to adapt its color to match its environment in order to evade predators or as a reaction to the time of the day and related temperatures, there are several differences between the two animals. Apart from the frog being an amphibian and the chameleon a reptile, chameleons can change to a broader range of colors (including pink, orange, red, yellow, and blue), differing degrees of brightness, and combinations of tones. The chameleon is also faster at its color changes than the gray tree frog, and there are other reasons besides camouflage for it to shift shades such as for social signaling.

Appearance

These frogs are particularly unique because they are not necessarily always gray. Instead, their color variation can range from gray to green or even brown. It truly depends on its current environment and activities. It regularly alters its color to match tree bark, but its belly is usually always white. The gray tree frog is very warty in appearance.

These frogs utilize a special grip on their hands and feet that allows them to climb vertically or horizontally with ease on trees and other objects.

They are considered a larger example of a tree frog, being anywhere from 1.25 to 2.25 inches long depending on the sex. So on average, the frog is about three-and-a-half times as long as an aspirin tablet. Compared to other tree frogs, like the pinewood tree frog and squirrel tree frog, the gray tree frog has a weightier build.

Two distinct features of adult frogs are the light spot beneath the eye and the bright orange coloration on the inner thigh. This bright color variation probably serves as a warning to potential predators.

Behavior

These frogs are solitary creatures and only spend time together during the breeding season. All other times of the year, they spend time hiding during the day and hunting during the night. During the day, they can be found disguising themselves under bark, rotten logs, leaves, and tree roots. It produces a sticky fluid from the tips of its hands and feet that allow it to climb into trees to hunt for food.

The male of the species has a loud and almost birdlike call. It will make this call for hours after dusk as a way to establish a breeding territory. The males can be aggressive, but generally only in the breeding season when they need to defend their territory.

They hibernate in the winter thanks to an adaptation that allows 80% of their body to freeze. They can survive extremely cold temperatures by hiding under rocks and other forest objects.

Habitat

These frogs are common in the eastern part of the United States and parts of southeastern Canada. This includes northern Florida over to central Texas, as well as all of South Carolina and Georgia. Being tree frog, they can usually be found in wooded areas, whether that is a forest or agricultural area. They will not be found far away from either trees or a source of water, like a swamp or pond.

They spend most of their time in high treetops but can be identified in the vegetation of fishless wetlands during their breeding season. In the summertime, it is not unusual for people to see them on windows looking for the bugs attracted to artificial lights.

Diet

This species of tree frog mainly feeds on different types of insects, such as snails, spiders, beetles, and the larvae of those insects. It spends most of its days high in treetops, where it can easily find moths, tree crickets, ants, flies, beetles, plant lice, spiders, and mites. It is comfortable jumping between branches to seek out its prey. They are opportunistic and will eat smaller frogs if given a chance.

Predators and Threats

These frogs are very common and probably have a large population. However, regional populations in both the United States and Canada have to deal with the threats of habitat loss, water pollution, invasive species, and chytrid fungus.

Different species of snakes, birds, small mammals, and even other frogs prey on these frogs. They spend most of their lives in the treetops to avoid these types of predators. They are also nocturnal and active at night to avoid predation.

A known threat to these frogs is pesticides and insecticides that they consume on insects. These chemicals may have harmful long-term effects.

Reproduction, Life Cycle, and Lifespan

The breeding season occurs after the frog wakes up from hibernation, in late spring and early summer. Males will defend an area around a water source and call out after dusk to find potential mates. Females will lay eggs in masses at the surface following mating. Each female will lay somewhere between 1,000 and 2,000 eggs in batches of 10 to 40. The eggs hatch between 3 and 7 days.

Young frogs are called tadpoles and live in the pond or water source they were hatched in until they are 4 to 8 weeks old. Then they complete a metamorphosis process and become young gray tree frogs or froglets.

The frog’s lifespan is believed to be on average 7 to 9 years. This lifespan is similar for males and females.

Population

These frogs are known to be widely distributed across their habitat in the U.S. and Canada. However, there are no accurate counts of its population in any region. These frogs are listed as Least Concern on the IUCN Red List. Most scientists believe there to be a large population that is generally not in danger of extinction any time soon.