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 The Green Treefrog (Hyla cinerea) is one of Louisiana’s most well known frogs. It is a common denizen of ponds, roadside ditches, canals, and swamps, often being found on doors and windows where it feeds on insects drawn by the porch light.
Green Treefrogs are appropriately named. The have a lime-green back (often with yellow or golden spots) and pale belly, separated by a heavy white lateral line that typically stops before it reaches the hind legs. This species has the ability to vary its color. When cool and inactive, a specimen may be olive drab to brown or gray; when warm and active, the same animal will be a beautiful shade of lime-green.
In Louisiana, Green Treefrogs are usually inactive during the cooler months. They begin to move about with the warming weather and begin breeding in late spring, an activity they continue as late as August. A gravid female may contain as many as 700 eggs, but she usually deposits them at the surface of pools in clutches of up to 40. The norm is for a female to develop one complement of eggs per season, but there have been rare records of Green Treefrog females doing so three times in one season. In any case, the eggs hatch after two days and the tadpoles metamorphose into froglets in about two months. Those little frogs will be ready to breed by the following spring.
One of the common names for this species is the Bell Frog. This name comes from the mating call for the species which sounds like a ringing bell: quonk, quonk, quonk. When calling in a chorus of individuals, they frequently harmonize and the call seems to be “quonk-quack, quonk-quack, quonk-quack.” To make matters worse, each male (females rarely vocalize) varies its call depending on circumstances. Studies have shown that Green Treefrogs tend to use a territorial call (one that tells other males to keep their distance) at dusk. Following this, the frogs slowly move toward the breeding pool. During this time, they use an encounter (which is rather antagonistic) call as they accidently bump into other males. When they reach the pool, they switch to their courtship (mating) call that is intended to attract the females for breeding. This call is the most familiar to local citizens, and research has shown that female Green Treefrogs can hear the call 300 yards away!
For most frogs, the mating pattern is for each adult male to sit and croak until a female is attracted. Our little critter, however, has an additional behavior. It is not unusual for one or more non-calling males to crouch near a calling male. Since they are scattered around the calling male, they are termed “satellite” males. Their purpose in the grand scheme of things typifies how Mother Nature works. Croaking all night to attract a mate uses a lot of energy. Somewhere along the line, Green Treefrog males found out that, if they simply crouch down and wait, the calling male will eventually either tire out and leave its prime territory, or it will be successful and its new female friend will hop away with him holding on for dear life toward the breeding pool. When this happens, one of the satellite males will assume the role of Excellent Croaker. Yet another way that they might save energy is by grabbing a female who is moving toward the fellow who has expended all the energy (even frogs don’t always want to work for their pleasures!).
Green Treefrogs eat just about anything they can get into their mouths. This usually includes insects, spiders, and the like. They seem to be an important part of the food chain, as they are eaten by many critters such as snakes, birds, turtles, fish, and mammals like raccoons and otters.
The fact that Green Treefrogs are so abundant and widely distributed in Louisiana makes them an excellent choice as the state amphibian.
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