The Bird-Voiced Treefrog

Back in December, a friend who lives in Covington called to ask, “What obnoxious bird is that I’m hearing at night? It’s keeping us awake. How can I get it to quit?” There were no birds calling then, nor could I think of a bird that could be categorized as “obnoxious.” Hmmm. I told her I’d think about it and get back to her with an answer.

December 2015 was an unusually warm month. The normal cold snaps that nip plants back never came, and the warm temperatures were confusing for both plants and animals. While putting out Christmas decorations one evening and pondering her question, I heard a loud sound in my backyard, a piercing call that I didn’t recognize. Maybe this was her mystery bird … except birds don’t call at night unless they are migrating or they are testosterone-ridden male mockingbirds singing at odd hours during breeding season (April—May). Something about that bird call didn’t sound right.

I immediately searched the Internet for some audio of the call of the Bird-voiced Treefrog (Hyla avivoca). I had heard of this frog-with-the-catchy-name before, but I’d never heard or seen one. Yep. It was a male Bird-voiced Treefrog, only he was supposed to be calling in April and May, not December. The warm weather had him all out of whack. 

Now that we are in May, the normal calling time for this amphibian, you might just hear one if you know what to listen for. Actually, you might hear the Western Bird-voiced Treefrog, which is the species found in Louisiana. They are not found throughout the state but mainly in the Florida parishes, those parishes just west and south of Lake Pontchartrain, and a few other areas in central and north Louisiana. (See the range map at louisianaherps.com/bird-voiced-treefrog-hyla-a.html, run by Brad M. Glorioso, an ecologist with the U.S. Geological Survey at the National Wetlands Research Center in Lafayette, Louisiana. He conducts frog surveys and, incidentally, said he has never heard a Bird-voiced Treefrog calling in Baton Rouge.)

My Covington friend lives in the Bird-voiced Treefrog range, and once she heard the recorded call (also found at Glorioso’s site), she agreed that her nightly serenades were from frogs, not birds. After another week or so, the weather cooled and naturally silenced the chirpy fellow.

This small frog can grow to about two inches long and has a dappled, pale grey or brown color on its back (dorsal surface); however, its color changes to pale green with increased temperature changes and activity levels. It often has a dark brown cross-shaped mark on its back and additional dark areas on its legs. The belly is grey, and a whitish square region is seen underneath the eye. Bird-voiced Treefrog males have a dark throat. 

These crooner treefrogs live in wooded swamps near water where the dominant tree species include cypress, birch, tupelo, and buttonbush. They are nocturnal and come out at dusk to search for insects and other small invertebrates.

The Bird-voiced Treefrog lives in trees and descends to the ground only to breed. They may “talk” from the trees for several weeks before going to breeding ponds. Breeding takes place in late spring, usually starting in April, and often after heavy rains. The male calls from bushes or trees close to the edge of ponds where the female will lay eggs. The tadpole stage lasts for about a month. Newly metamorphosed froglets disperse to other localities in wet weather.

The Bird-voiced Treefrog only sings at night, so you might need to have some earplugs handy!