Frogs and Toads of North America

Voice: The advertisement call is a nasal, buzzing quack that is briskly repeated around two times per second: rrraak-rrraak-rrraak-rrraak ... The Squirrel Treefrog gets its name from another call, a squirrel-like "rain call" that it gives from shrubs and trees away from breeding areas. The rain call is weaker and more raspy than the advertisement call and is reminiscent of the scolding notes of gray squirrels. Photo © Lang Elliott.

Classification — Family Groups

Frogs and toads are members of the order Anura, which is Greek for “tailless” (an, “without”; oura, “tail”). They are often referred to as anurans and there are nearly 5,300 species worldwide. In North America (north of Mexico), there are currently 97 native species and 4 introduced species of frogs and toads, for a total of 101 species. Scientific research into the taxonomy and classification of anurans continues, and the number of species is expected to grow, as new species are discovered with the help of modern genetic, biochemical, morphological, and behavioral analyses.

The frogs and toads of North America fall into nine family groups, which are described briefly below. More information about these can be found in the family introductions accessible by clicking the "More Info" links. The photographs below show a representative member of each family group.

Squirrel Treefrog © Lang Elliott.

Hylidae — Treefrogs & Allies: This is a large and diverse family, thirty species of which are found in North America (north of Mexico). The group includes the treefrogs, chorus frogs, cricket frogs, and several tropical species that just barely range into the United States.

Bufonidae — True Toads:

Known as the true toads, twenty-two species are found in North America. This family includes the common hop toads, recognized by their chunky bodies, large wartlike glands on their skin, and terrestrial habits. More Info. Photo © XXXXX XXXXX.

Ranidae — True Frogs:

Referred to as the true frogs, twenty-eight species live in North America. This family includes many of the familiar pond and lake frogs, including the Bullfrog, Green Frog, and various species of leopard frogs. More Info. Photo © XXXXX XXXXX.

Scaphiopodidae — Spadefoots:

This small family is composed of seven species of North American spadefoots. They are a group of chunky, toadlike burrowing anurans with spadelike projections on their hind feet that aid in digging. More Info. Photo © XXXXX XXXXX.

Leptodactylidae — Tropical Frogs:

This is a large family of New World tropical frogs; only seven species range into the United States, mostly in Texas, Arizona, and Florida. Nearly all members of this group lay their eggs on the land; the larval stage is passed inside the egg. More Info. Photo © XXXXX XXXXX.

Rhinophrynidae — Burrowing Toads:

This family consists of a single species, the Mexican Burrowing Toad, which is found in the United States only in extreme southern Texas along the lower Rio Grande River. More Info. Photo © XXXXX XXXXX.

Behavior: Squirrel Treefrogs are mainly explosive summer breeders that form large choruses lasting only a night or two. The males congregate and call excitedly from temporary ponds, pools, and roadside ditches. (In many cases, however, these bodies of water dry out before the tadpoles have a chance to transform.) Even when there has been little rain, isolated males may be heard calling in the shallow parts of semipermanent and permanent ponds. Satellite behavior (LINK GOES HERE p. 24) is common, and a large male may have several satellites positioned near him, all attempting to intercept females that are attracted to his loud calls.