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	Types of frogs

	Bullfrog, common name for a frog of the true frog family, named for the males' deep resonant call, which sounds something like a bull's bellow. The bullfrog is the largest frog in the United States. Native to eastern North America, it is found from Canada to Mexico around quiet lakes and ponds. It has also been introduced into some western states and many other parts of the world as a source of food. The frog's hind legs (up to 25 cm/10 in) are longer than its body (20 cm/8 in) and are often consumed as a delicacy. The introduction of bullfrogs into many areas has led to serious environmental consequences because they readily devour native wildlife, including other species of frogs. Bullfrogs are dull green, with a yellowish or whitish belly and dark, barred legs. The large “ears,” or tympani, behind the eyes are specifically receptive to the mating calls of other bullfrogs. On spring nights, males give their calls from the water's edge. They are aggressive in defending their territories and attack intruders violently. The female lays up to 10,000 eggs, which hatch into dark-spotted tadpoles. The tadpoles take a year to mature into frogs in warm climates, and two or three years in cooler climates. Certain frogs found in Africa, India, and Malaysia are also called bullfrogs. Scientific classification: Bullfrogs belong to the family Ranidae. The American bullfrog is classified as Rana catesbeiana.



	Chorus Frog, common name for any of seven species of small, mostly terrestrial members of the tree frog family. The western chorus frog and Strecker's chorus frog are representative species. These stout-bodied frogs have smaller toe pads and less foot webbing than most tree frogs. Body coloring may be gray, brown, or light green, interrupted by irregular spots and stripes. Chorus frogs occur over much of the eastern United States and southern Canada in habitats ranging from upland forests to prairies. Adults reach 2 to 4 cm (0.75 to 1.6 in) in length. Females are larger than males. Male chorus frogs have dark, wrinkly throat skin—the vocal pouch used to produce their mating calls. Some chorus frogs make a sound like that of a finger running over the small teeth of a plastic pocket comb. Chorus frogs mate in the winter or early spring, usually in shallow water. During mating season they are rarely seen away from their breeding sites. At other times of the year they are concealed in vegetation or are buried in the ground. They feed on small insects. Scientific classification: Chorus frogs belong to the genus Pseudacris, in the family Hylidae. The western chorus frog is known as Pseudacris triseriata and Strecker's chorus frog as Pseudacris streckeri.



	Cricket Frog, common name for either of two nonclimbing species of the tree frog family. These small frogs, which rarely exceed 3.8 cm (1.5 in) in length, are found from New York to northeastern Mexico. They have warty skin, a dark triangle between the eyes, and a black stripe on the back of the thigh. They do not have the enlarged toe tips characteristic of climbing tree frogs. Their coloration and pattern vary, including combinations of black, yellow, orange, or red markings on a brown or green background. Cricket frogs inhabit shallow ponds or lakes that have enough vegetation to offer cover and that are exposed to the sun during most of the day. Males have a single vocal pouch under the chin, and their name is derived from their peculiar rattlelike or metallic clicking calls. Cricket frogs feed on small insects and other arthropods. They lay their eggs in the water, and the larvae, known as tadpoles, transform into tiny froglets through a process known as metamorphosis. Scientific classification: The two species of cricket frog are the northern cricket frog, classified as Acris crepitans, and the southern cricket frog, classified as Acris gryllus. They are members of the family Hylidae.



	Green Frog, common name for a small water frog of eastern North America. Its body color ranges from brown and bronze to green, and the male has a bright yellow throat. Large adults are about 6 to 8 cm (about 2 to 3 in) long. Unlike the bullfrog and some other relatives, the green frog has paired folds of skin along the sides of the back. Like other frogs, it has a spinal column that is short, rigid, and flexibly hinged; a long pelvis (the hump visible about two-thirds of the way down the back); and greatly enlarged hind legs. When the frog straightens all of these parts at once, it becomes a projectile and can escape predators by leaping between radically different environments, from land to water. Green frogs are usually found near water, including swamps, streams, lakes, ditches, and ponds. They feed largely on insects and other invertebrates. A male green frog's call has been likened to the sound of a loose banjo string being plucked. The call is produced by paired vocal pouches, one on either side of the head. Green frogs breed in the spring and summer, producing aquatic eggs that hatch into tadpoles. Scientific classification: The green frog is known as Rana clamitans. It is a member of the family Ranidae.



	Tree Frog, also tree toad, common name for a family of small to medium-sized, often brightly colored frogs, found in temperate and tropical areas throughout the world. The males of many species have calls ranging from melodious chirps to raucous growls. They call during the breeding season, which generally coincides with wet, rainy periods, and in some areas these frogs are considered indicators of imminent rain. Unlike their terrestrial relatives, most tree frogs have expanded disks at the tips of the toes that enable them to cling tightly to vertical surfaces. Body color ranges from brown and gray to green; some species are able to change color in response to temperature and light. The gray tree frog is common throughout the eastern United States. It ranges in color from dark brown to mottled gray; has a short, rounded head; and is about 5 cm (about 2 in) long. In winter the gray tree frog buries itself in the decayed stumps of trees or within the earth until spring. During the spring the female lays one to several hundred eggs in a pond; the eggs become attached to plants and hatch in several days. The diet of tree frogs consists mainly of insects. The Pacific tree frog is abundant in the western coastal region of North America and is usually green or brownish with a dark eyestripe. The largest known tree frog, the giant tree frog, is native to New Guinea and northern Australia and may attain a length of about 11 cm (about 4.25 in). Scientific classification: Tree frogs make up the family Hylidae. The gray tree frog is classified as Hyla versicolor, the Pacific tree frog as Hyla regilla, and the giant tree frog as Litoria infrafrenata.

	Courtesy of Microsoft® Encarta® Encyclopedia 2002. © 1993-2001 Microsoft Corporation..