July was too hot and dry for man or beast. One of the consequences is that evenings were quiet. I don't think I heard a frog or toad the entire month.
Then the rains came, and the temperature dipped. Toads began to trill each evening, and the nightly chorus of crickets and katydids began.
Then one evening during the first August rain, I heard a familiar sound above the drumbeat of raindrops on the metal porch roof. I immediately thought screech owl because the sound was a monotone trill. But it was too brief for a screech owl. This trill lasted only a second or so. Then I heard it again. It was a gray tree frog.
Over the years I've heard them in Georgia, Oklahoma, Maine and Pennsylvania. The first time was in Georgia's Okefenokee Swamp. It was during an extended college field trip to catch, see, and hear critters. As alligators bellowed in the distance, gray tree frogs and squirrel tree frogs lulled us to sleep as mosquitoes buzzed inside our tents.
In Oklahoma it was on a field trip to the northeastern part of the state that I heard this frog, only this time I was an instructor rather than a student. We heard them on night hikes as we listened for owls and whippoorwills.
In Maine the sound came from a single tree in a huge paved grocery store parking lot. I caught that one and let it use the suction cups on its toe pads to cling to my eyeglasses to show my daughters a live tree frog. I never did figure out how or why it made its way to such an inhospitable island of habitat.
In Pennsylvania, I've heard gray tree frogs in many state parks. And in West Virginia, I hear them from my back porch.
What's notable about these recollections is that though I've heard many gray tree frogs, I've seen few. And that's typical. Gray tree frogs, when silent, are nearly invisible thanks to incredibly cryptic coloration. They are masters of disguise. By day, they hide inside cool, dark tree cavities or behind slabs of bark. At night they emerge to eat, sing and mate. When gray tree frogs are abundant, their chorus can be quite noisy.
Look for singing gray tree frogs on wet leaves on the ground, on fallen logs, or even on small tree branches overhanging a pool of water. Move slowly as you zero in on the sound, and use a flashlight to try to spot the singer.
Sticky adhesive pads on their toes enable tree frogs to cling tightly to tree trunks and branches. There they wait patiently and silently for tasty flies, beetles, caterpillars, aphids and moths.