You’re walking through the forest, and you come across a medium sized frog. It’s just sitting there on a pile of semi-decomposed  leaves and seems to be greenish-grey in color. You think that it is cute, and take it home, and put it in a card board box until you can find a better container for it. You leave it alone for a while, then return to the frog to see that it changed color! What kind of frog is it anyways? 

 

H. versicolor is a normal sized frog, going from about 1¼-2 inches. Its skin is rough and  is covered with warts, but is not that warty compared to toad. It is often multi-colored, and shades of grey are most common with black spots on the back. Sometimes, you can see browns, greens, mixed in there too. Green colors are more common during breeding season, and also in younger frogs. Most Grey Tree Frogs have white spots under their eyes, and have orangey-golden skin under their hind legs. The stomach region of H. versicolor is white. The Grey Tree Frog has two amazing adaptations that allow it to survive in its environment. The frog can easily cling to trees and man made structures, because of a mucus that the toe pads secret. The mucus is not the only thing that keeps the frog scaling safely though,  The toe tips are flexible and can grip more firmly to the surface that it is climbing, because of a small bone between the toe bones that support the toe pad. Coloration is another adaptation of the Grey Tree Frog, its color varies depending on the color of its background, and also on the season and humidly of its environment.  The coloration not only can protect if form predators, but also help it hunt.

 

Grey Tree Frog eat most types of insects and their larvae. They also snails. “Gray Tree Frogs mostly hunt insects in wooded areas in small trees and shrubs, where they may rely upon their camouflage with less risk of predation.” (University of Michigan Animal Diversity Web) Like most frogs, the Grey Tree Frog will eat smaller frogs, even other Grey Tree Frogs! H. versicolor plays a very important role in the food web of their ecosystems. As tadpoles they may eat enough algae to change the population of a certain species of algae in the pond.  After they go though metamorphosis, they eat enough pests like mosquitoes, gnats and flies to reduce the total population in a single frog’s territory. In turn, the Grey Tree Frog are the prey of larger frogs, some birds and other small mammals.  H. versicolor avoids being eaten by it’s color changing adaptation, and also by calling after dusk, and being most active in the evening and at night. They almost never leave the trees, unless it is breeding season. 

 

The Grey Tree Frog  live in forests at all elevations, near a water source, such as a lake, stream, or a swamp. They’re often found in different places, depending on the time of year. In the summer, they are found in rotten logs or hollow trees. In winter, Grey Tree Frogs hibernate under wood debris like logs, roots and dead leaves. Grey Tree Frogs live in a large part of the United States and some parts of Canada.  The“ Hyla versicolor inhabits a wide range from southern Ontario and Maine, westward to central Texas, northwest to Manitoba, and northern Florida. An isolated colony is also noted in New Brunswick.” (University of Michigan Animal Diversity Web) It is more likely to find H. versicolor in the north and northeastern of this range, like in the Great Lakes region, and most of southern Michigan. The Grey Tree Frog has a huge range of habitat, but how many are there?

 

The Grey Tree Frog’s status on the Endangered Species List is Least Concern, meaning that this animal is in no danger of going extinct any time soon. “The total adult population size is unknown but it is abundant and probably stable.” (IUCN Red List of Threatened Species). The only threat in the future of this remarkable species is the introduced bluegill sunfish, which  might cause a drop in the number of Grey Tree Frog tadpoles. 

 

The Grey Tree Frog is an amazing amphibian, with many interesting traits. One of the most amazing things is that there are actually two species of Grey Tree Frogs! H. versicolor, and H. chryoscelis, are living examples of speciation. It is believed that the Grey Tree Frog evolved from Cope’s Grey Tree Frog (H. chryoscelis)  around the time of the Ice Age. Seeing as this is a very short time in evolution, there are only two ways to tell these two apart. Firstly, the Cope’s Grey Tree Frog has a faster and higher pitched mating call than the Grey Tree Frog.  Also, the Cope’s Grey Tree Frog is a diploid, like most animals, and the Grey Tree Frog is a trepiloid, a trait more commonly found in plants. The Grey Tree Frog is unique and interesting for many of its own reasons, and was enjoyable to research.

 

Author: Rebecca B.

Published: 02/2010

 

Sources

1.  Mueller, L. and J. Harding. 2006. "Hyla versicolor" (On-line), Animal Diversity Web. Accessed January 25, 2010 at