The toads and frogs evolved from salamanders some 180 million years ago (Triassic period). They have changed little since they developed the large, jumping-type legs, and have become very successful. Today there are over 2,600 species of toads and frogs, and they live in a variety of environments.
With proper care, most toads and frogs do quite well in captivity. Knowing their natural history can help to furnish the keeper with the information necessary to keep these amphibians in good health.
Selection of Species to be Kept.
The selection of the proper anuran (toads and frogs) for you to keep depends partially on where your interests lie. If you are interested in toads, then the common species in your area may be selected (Missouri common toads include the American and the Fowler’s toad). The very large Marine toad, Bufo marinus, is a species that is quite hardy in captivity, and are not expensive to purchase.
Spadefoot toads (genus Scaphiopus) are rather difficult to collect, except during their breeding season, and they are extremely shy and rather difficult to keep. They do not make a very good study animal because they tend to spend a great deal of time buried at the bottom of their vivarium.
The treefrogs generally do well in captivity, but only the larger species should be considered. The very small varieties should be delicate, and require very small insects to feed on. The gray treefrog (Hyla versicolor) and green treefrog (Hyla cinerea), both are found in Missouri, as well as the barking treefrog and Cuban treefrog (Florida species), are easily kept, provided they are given a variety of live insects to eat.
The majority of true frogs (genus Rana) can be kept with little trouble, but—as with all animals—they should be kept as clean as possible. The leopard frog (Rana pipiens, blaira, and utricularia) will do well, so also will the green and bull frog (Rana clamitans and R. catesbeiana).
Because they are bred in captivity, the clawed frog, Xenopus, of Africa is available in many pet stores at reasonable prices. These completely aquatic frogs can do quite well in captivity. Another tropical frog species that is often sold in pet stores is the South American horned frog, Ceratophrys, which will eat both crickets and baby mice.
Choosing other species not listed in this section will have to be done at the discretion of the person keeping them. You may choose a species that is either too fragile (as with very small toads or treefrogs), or, if exotic species are what you are interested in, their price may be the deciding factor (some Central American frogs can be expensive).
No matter what type of toad or frog you intend to keep, remember that they require live food, and should never be kept in crowded conditions. Thus, keep in mind that insects are difficult to secure in the winter, and, the more specimens you have, the greater the problem will be to feed them. It is recommended that only one or two toads or frogs be kept at one time—get to know the animals, learn from them, and then move on to other species. Release native species in a suitable area—but never release non-native species into a new area ... give them to a zoo or biology teacher.