The Frog Listening Network

Anurans (frogs and toads) of the Hillsborough River

Frogs and toads are collectively known as anurans, which loosely translated means amphibians without tails. Because anurans are amphibians and therefore need to reproduce in an aquatic environment, the best place to listen for calls is near a body of water such as a pond, swamp, river, stream or even a road side ditch. Just like birds, different species of anurans need different aquatic environments for reproduction. For example, because the larva (tadpoles) take a long time to mature, pig frogs, bull frogs and leopard frogs prefer large bodies of water that will not go dry before the tadpoles metamorphose into adults. Conversely, the gopher frog and many tree frogs require small temporary ponds in pine flatwoods and sandhills that will dry up during the dry season. This is because small ponds that go dry lack fish, which tend to eat the small eggs and tadpoles of these species. This habitat specificity will sometimes help you in identifying the species you hear calling. The time of year may also aid in identifying the species heard calling. For example, during the Spring and Summer YOU can hear most tree frogs, pig frogs, and bull frogs. If you want to hear narrow mouthed toads, the best time is August.

Anurans can be heard calling at almost anytime. The best times, however, are either right before a rainstorm, in which case you can hear green tree frogs giving the "rain call", or at night following a rainstorm.