Tree frogs have the typical frog shape, with long hind legs and smooth, moist skin. One of the characteristic features of tree frogs is the disc-shaped, adhesive pads on their fingers and toes, which help them climb about in trees.
IN THE REAL WORLD
Tree frogs are a diverse family of amphibians that includes over 800 species. Not all tree frogs live in trees. Rather, the feature that unites them has to do with their feet—the last bone in their toes (called the terminal phalanx) is shaped like a claw. Tree frogs also have toe pads to help them climb and many have extra skeletal structures in their toes. Tree frogs can be a variety of colors, but most of the species found in the United States are green, gray, or brown. Some of them, like the squirrel tree frog (hyla squirella), are chameleon-like in their ability to change color.
Although tree frogs can grow to be a range of sizes, most arboreal species are very small because they rely on leaves and slender branches to hold their weight. At 4-5.5 inches (10-14 centimeters) long, the white-lipped tree frog (litoria infrafrenata) from Australia and Oceania is the largest tree frog in the world. The largest tree frog in the United States is the non-native Cuban tree frog, which reaches 1.5-5 inches (3.8-12.7 centimeters) in length. The world’s smallest tree frogs are less than an inch (2.5 centimeters) long!