Hyla avivoca
bird-voiced treefrog

The bird-voiced treefrog Hyla avivoca is most commonly found in deep wooded swamps with emergent woody vegetation in the south-eastern United States (Knapp 2001, Behler 1979).

Bird-voiced treefrogs prefer swamps and brushy areas and are usually found in trees that grow in water. (Georgia Museum of Natural History 2000)

Adult length 28 mm to 51 mm (1.25 inches to 2.25 inches).

The backs of bird-voiced treefrogs are gray, brown or green, often have one or more dark spots and have a warty surface. They have light, sometimes white, spots under their eyes. They have large toe pads, with adhesive disks on the tips of their digits. The hidden surfaces of their thighs and groin area usually range from light green to white and they have dark bars on their hind legs. The species is dimorphic, females are usually larger than the males. The males range in size from 28 mm to 39 mm (1.25 inches to 1.75 inches) and the females range from 32 mm to 51 mm (1.5 inches to 2.25 inches). The males have a darker throat pouch than the females. The tadpoles, prior to metamorphosis, are black and have several orange bands on their tails and an orange spot on their heads. (Wright 1949, Northern Prairie Wildlife Research 2001, Georgia Museum 2000)

Bird-voiced treefrogs are usually found in shrubs around swamps. They are nocturnal and arboreal. They descend from the trees only to breed. Males will perform their mating call perched on tree limbs 610 mm to 2440 mm (2 to 8 feet) above water. They can only be heard calling during breeding season. The call is a series of bird-like whistles, given at a rate of several per second, rapidly repeated numerous times. The call has been compared to that of whistling for a dog.(Northern Prairie Research Center 2001, Conant 1958, Behler 1979, Auburn University 2001)

Bird-voiced treefrogs are opportunistic feeders. Their diet consists mainly of spiders and small arboreal insects. They typically hunt for their prey by foraging about in trees and shrubs. (Illinois Department of Natural Resources 1998)

None Known

By eating small insects these frogs may keep pests populations lower.

Bird-voiced treefrogs are classified as a threatened species in the state of Illinois. This is the northern most portion of the species' range, and these frogs occur only in a few cyprus swamps in the extreme southern tip of Illinois. It is listed as threatened because it occurs only in these few locations. Its population can be affected by any river damming or swamp drainage that causes changes to swampy land. (Georgia Museum of Natural History 2000)

There are two known sub-species to the Hyla avivoca, the western bird-voiced treefrog, Hyla avivoca avivoca, and the eastern bird-voiced treefrog, Hyla avivoca agechiensis. Hyla avivoca avivoca are smaller in size and has a light spot under their eyes. They are most commonly found from Illinois to Louisiana and west Florida. Hyla avivoca agechiensis is larger in size with either yellow or light green spots under their eyes. They are most commonly found in central Georgia and southwest South Carolina.

Bird-voiced treefrogs emit skin secretions that are very irritating to humans. These secretions can cause runny noses and watery eyes. (Behler 1979)