Home / Animals of the Upper-Midwest / Amphibians / Gray Tree Frog

Gray Tree Frog (Hyla versicolor)

Gray Tree Frogs Sunning on Swamp Grass View Enlarged Image

Toe Pad Grappling Hooks

If you've ever looked out a window or patio door on a warm summer night to see a mottled white belly hung like a Garfield cat on four sets of suction-cup toe pads, you've spotted the Gray Tree Frog attracted by mosquitoes and other insects that are drawn to household light. Their climbing ability, which they apply to scaling plants and trees in the wild, is achieved by a sticky substance they secrete over their oversized toe pads. A subspecies, the Cope's Gray Tree Frog (Hyla chrysosclis), is distinguishable by its larger toe pads and higher-pitched trills. They spend much of their lives high in trees, or occasionally in plants, where they catch spiders and flying insects.

While tree frogs are common, they're sometimes difficult to spot. Not only is their bumpy green skin great camouflage in the high branches of trees, but they can adapt the color of their skin to match their surroundings (kind of like a chameleon, though more limited.) Their tone can change from an almost solid green to mottled gray, depending on their surroundings, activity, and the time of year.

The best time to spot a Gray Tree Frog is in mid to late Spring (in Stillwater, MN we usually start to hear their calls towards the end of April), when males will call both night and day for a mate. This call is a two or three-second long reverberating trill. Single calls can be soothing on a quiet evening, while a full chorus can be almost deafening.

Promoting our Frogs

Gray Tree Frogs and other amphibians are endangered by runoff, water pollution, pet predation and habitat destruction. You can promote them in your backyard by creating water gardens, landscaping with native rocks and creating "frog houses" by digging shallow ditches (no more than 5" in diameter and 2" deep and placing flat rocks or plywood over them. There should be just enough room at one end to allow a frog to enter, and the lid should be heavy enough (weighed down with dirt or rocks) so that predators such as fox, raccoons and house pets cannot get in.

Interesting facts about the Gray Tree Frog:

• Like many frogs, Grays can practically freeze solid as they hibernates in winter. There is a kind of antifreeze component to their blood that keeps ice crystals from forming and tearing apart organs and vessels.
• Female Grays, sometimes mistaken for another species, are a larger than the males.

Multimedia:

Gray Tree Frog inflating throat sac | 1.11 MB MPEG-1 Video | Stillwater, MN Gray Tree Frog trill | 813 Kb WAV Audio | Stillwater, MN

Add to our growing wildlife encyclopedia! Submit a photo or other footage of this species!*

Want to Learn More?

In an effort to make our site as comprehensive as possible, we have supplemented our online park and wildlife survey with other educational resources. Every book we recommend has been hand-picked by a Beyond Main Street volunteer. 7.5% of all proceeds from the links below go to help Beyond Main Street build a larger, more comprehensive site!

Stan Tekiela's Reptiles and Amphibians of Minnesota

*Submissions are full and credited property of their original owner. The name of the sender will be printed below the submission unless otherwise requested. BMS maintains one-time printing rights only. For legal reasons, all video and photography must be your own work. If there is a copyright on it, you must own it. Video, photos, and writing must have been created in Minnesota or surrounding area to be added to our database.