SCOTT SHALAWAY Gray tree frogs are reclusive but melodious
Drought kills; water revives. Above-average rainfall over the last three years has been great for gardens, wells, seeps, springs and all that depend on them. High on that list are frogs and toads, which lay their eggs in ponds, pools and even temporary shallow puddles.
Recently, during a brief shower, I stepped onto the porch for a listen. I heard only raindrops. No insects, no birds; just raindrops.
Then a familiar sound rose above the rhythmic drumbeat of raindrops on the metal roof. I immediately thought of a screech-owl because the sound was a monotone trill. However, it was too brief for a screech-owl. This trill lasted only a second or so. Then I heard it again. And again. Soon I was hearing the short trill every few seconds.
My brain went into search mode to retrieve the sound stored somewhere in the cobwebs of my scattered mind. I knew I'd heard the sound before, but retrieval was slow. Finally, the name materialized: "Gray tree frog." Slowly my memory provided details. Over the years I've heard it 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. They lulled us to sleep as mosquitoes buzzed inside the 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. In Maine, the sound came from a single tree in a huge paved grocery store parking lot. I caught that one to show my daughters a live tree frog, but I never figured out how or why it made its way to such an inhospitable island. In Pennsylvania, I've heard gray tree frogs in many state parks. Now 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. That's typical; gray tree frogs, when silent, are nearly invisible thanks to incredibly cryptic coloration. By day, they hide inside dark cool 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.
Sticky adhesive pads on their toes enable them to cling tightly to tree trunks and branches. There they wait patiently and silently for tasty flies, beetles, caterpillars, aphids and moths.
Though most breeding occurs by early June, gray tree frogs sing throughout the summer, especially on cool, wet nights. If ever you find one, you'll be impressed by the big sound that comes from such a small creature. Gray tree frogs usually measure less than two inches in length, and their appearance varies. Depending on light, temperature, moisture, temperature, stress or activity level, they may be gray, green or brown. Thanks to this cryptic coloration, they are extremely difficult to spot, even during the day. Two fairly reliable field marks, however, are bright orange inner hind legs and, unlike most frogs, coarse skin. Their body is quite warty, though the individual warts are much smaller than those found on toads.
Going to ground
Gray tree frogs leave the safety of trees for the ground for only two reasons.
Like most amphibians, they gather at water's edge to make more tree frogs. Responding to the males' song, females locate males and engage in a mating embrace called amplexus. As a female releases as many as 1,000 individual eggs, the male fertilizes them. The eggs drift downward or float away and eventually settle on aquatic vegetation, sticks or other submerged debris. In six to 12 days, depending on water temperature, the eggs hatch into tadpoles with red tails. In two to three months, again depending on temperature, the tadpoles transform into small frogs.
As winter approaches, gray tree frogs again leave their arboreal refuge to seek shelter under logs or leaf litter. There they remain dormant until spring, when their cycle of life resumes.
XSend questions/comments to Dr. Scott Shalaway, R.D. 5, Cameron, W.Va. 26033 or via e-mail to firstname.lastname@example.org.