First important fact – all toads are frogs, but not all frogs are toads! Frogs and toads are members of the order Anura. Secondly, these amphibians are critical indicators of the health of our environment. Their sensitivity to pollution and changes in the local environment make frogs and toads the animals to watch for early signs of environmental degradation.
Oregon spotted frog
Generally speaking, though, when we think of frogs, we generally picture what are called “true frogs”, members of the family Ranidae, containing more than 400 species.
These frogs have the characteristics of:
- two bulging eyes
- strong, long, webbed hind feet that are adapted for leaping and swimming
- smooth or slimy skin (generally, frogs tend to like moister environments)
- frogs tend to lay eggs in clusters
- a frog will most likely being the water when you see it
- a frog is more timid than a toad, and might hop away immediately
- frogs have sticky long tongues they can use as lashes to reach out for food
Frogs from this family can be found on every continent except Antarctica. They are referred to as the “true frogs” because of their generalized body form and life history. Members of this family include the bullfrog, common frog, green frog, leopard frog, marsh frog, pickerel frog, and wood frog.
Left, American toad; right, Fowler’s toad
The term toads tends to refer to “true toads”, members of the family Bufonidae, containing more than 300 species.
These types of frogs have are characterized by:
- Stubby bodies with short hind legs (for walking instead of hopping)
- Warty and dry skin (usually preferring dryer climates)
- paratoid (or poison) glands behind the eyes
- the chest cartilage of toads is distinctive from frogs.
- toads tend to lay eggs in long chains. (There are some toads, genera Nectophrynoides, however, that are the only types of anurans to bear live young).
- a toad will most likely be on land and farther away from the water than a frog
- toads may stay still when approached, or hop a shorter distance than a frog
- toads do not have sticky long tongues of a frog, but must walk up to its food to devour it
True toads can be found worldwide except in Australasia, polar regions, Madagascar, and Polynesia, though Bufo marinus has been artificially introduced into Australia and some South Pacific islands.
Besides Bufo, the family includes 25 genera, all of which, like the frogs, are anura.