Tree Frog, or Tree Toad, any of several kinds of climbing frogs or toads. Most live in trees, but some inhabit smaller plants, and a few species are ground-dwellers. Tree frogs are found in most parts of the world. They vary in length from less than one inch (2.5 cm) to more than four inches (10 cm).
Tree frogs have pads at the ends of their fingers and toes. These pads help in climbing because they are rough and are covered with a sticky secretion. Some tree frogs have claw-shaped fingers and toes, and most kinds have webbed hands, webbed feet, or both. Many tree frogs can change color, usually to match their surroundings. As winter approaches, tree frogs burrow into the humus on the forest floor. Their tissues and body fluids are protected from freezing by glycerol, a type of alcohol made in the frogs’ cells.
Tree frogs are noted for the loudness and variety of their mating calls, made only by the male. Most tree frogs lay their eggs in water. There is variety in their breeding habits, however, especially among tropical American species. Some lay their eggs on leaves overhanging water into which the tadpoles, or larvae, fall after hatching. The tadpoles of certain other species are carried from tree to stream on the back of the male frog. The female of some kinds carries her eggs in a pouch on her back where they hatch and the tadpoles remain until they metamorphose.
Zoologists use the term true tree frogs to describe only those belonging to the family Hylidae. The only tree frogs found in the United States belong to this family. They include:
Tree-dwelling. The body is 2 to 2 1/2 inches (5 to 6.4 cm) long. It is pale gray to brown on back with one or more large greenish blotches, but is capable of marked color change. Found over most of the United States west to the Great Plains and into Canada.
The common tree frog is Hyla versicolor.
Some live on the ground, others in trees. About 1 1/4 inches (3 cm) long. Usually brown on back with a dark cross-shaped marking. Range is about the same as that of the common tree frog.
The spring peeper is H. crucifer.
Ground-dwelling. Body is nearly two inches (5 cm) long. The back is extremely variable in color, with various markings. This frog is found from the Pacific Coast eastward into Nevada, Idaho, and Montana.
The Pacific tree frog is H. regilla.
Ground-dwelling. Body length is about 1 1/2 inches (4 cm). The back is greenish gray with five darker stripes or rows of dots. The chorus frog is found from the Atlantic Coast west to Montana and southern Idaho, and in New Mexico and Arizona at high elevations.
The chorus frog is Pseudacris nigrita.
Semiaquatic. Body length is a little more than one inch (2.5 cm). Wide variation in color from gray to greenish red, with darker or contrasting markings. Found over most of the United States west to the Rocky Mountains and into Mexico and Canada.
The cricket frog is Acris gryllus.