When many people think of treefrogs, images of the tropics, jungles, and rainforests come to mind. While the equatorial regions are home to many treefrogs, including the popular and colorful Red-eyed Treefrog, the northeastern United States is also home to its share of Hylids (Treefrogs). Among these is the Gray Treefrog, Hyla versicolor.
If you live in an area with Gray Treefrogs, you most likely hear them more often than seeing them. Because Gray Treefrogs will call from up high during the day and well into August in some parts of their range, many people mistake their calls for birdcalls. Coloration can vary; even with the same individual at different times of day, but a few distinguishing characteristics of the species are a stout appearance, light spot with dark edges beneath the eye, and a yellow groin area. (Seems to be a theme with frogs) Gray Treefrogs always looked “bumpy” to me, in comparison to a smoother skinned treefrog such as Pine Barrens or Red Eyed. Smaller younger individuals are sometimes green instead of gray, but still share the above characteristics. To see photos of this frog and other NY species check out the Frog Slideshow.
Cope’s Gray Treefrog, Hyla chrysoscelis, appears identical to the “regular” Gray treefrog, and was even once considered the same species. But Gray treefrogs have double the number of chromosomes of the Cope’s frogs, making them the only tetraploid (4 sets of chromosomes) frog in the US.
If you are trying to find and observe these guys you might notice frustratingly that they will call loudly until you get close enough to pinpoint their location, then they will go silent, becoming almost invisible in the foliage. They like to lie close to the bark of trees, but unless they are low down and easily found, who wants to get bit by 100 mosquitoes trying to find them. Sometimes at night during the chorus it’s a little easier as many frogs will be in the water, and at that point they are usually so distracted and “love drunk” they can be picked up and will continue to call from your hand.
In fact calling is a big deal for Gray Treefrogs. It takes a lot of energy, and males will often have to take a night off to recuperate after spending time in the breeding chorus. Females (as usual) seem to prefer the longest, most energetically costly calls to the short ones, and will head in the direction of those calls. So, if you are a male that isn’t “all that”, it can pay to hang around males that are, and possible intercept and trick incoming females into mating with you. And some males do just that.
So next time you hear that “bird” calling from the trees in the summer take a closer look and listen. You may find treefrogs closer to home than you think!