INTRODUCTION
Frogs and toads are amphibians, a group of vertebrates that also includes the salamanders. The term "frog" is generally used for those species that have relatively smooth skin and long rear legs, while "toads" usually have warty skin and relatively short rear legs. However, neither term has a precise scientific definition and there are no set rules for distinguishing a frog from a toad. Many frogs and toads, including all of those occurring in Mississippi, lay their eggs in water and have an aquatic tadpole stage.
Mississippi has five major groups of frogs and toads, including the toads (Family Bufonidae), narrow-mouthed toad (Family Microhylidae), spadefoot (Family Pelobatidae), treefrogs (Family Hylidae) and the "true" frogs (Family Ranidae). All of these groups are represented on this tape, and members of each can be found in most parts of the state.
Most frog and toad calls or vocalizations are produced by males. These sounds serve a variety of functions. Calls may be used to attract females to the breeding area, or notify other males of territorial claims to a particular area. Calls may even be emitted when one male encounters another of the same species. In some cases, a vocalization may function as both a courtship and a territorial call. This generally occurs in those species, such as the bullfrog, which have an extended breeding season. Frogs and toads may also produce distress calls and release calls. Distress calls are made when the frog or toad is captured by a predator. Release calls are given by males or non-receptive females when grasped by an amorous male. It indicates to the grasping male that it has made a mistake. Almost all of the vocalizations on this album are courtship calls.
Frogs which call in groups are referred to as choruses, and choruses can be composed of from one to several species. In certain species such as the green treefrog, calling males may form duets, trios, or quartets. Males in these groups alternate their calls, producing an almost rhythmic effect. This behavior presumably enables a male to maximize his chances of attracting a female while minimizing call interference from neighboring males.
Frogs and toads call from a variety of locations around the breeding site. Some species call while floating on the surface of the water, some from perches in trees or shrubs around the edge of the pond, and others call while hidden beneath vegetation or other debris at the water's edge. Determining the location of a calling frog or toad can sometimes be difficult, since many species seem to be able to "throw" their voices and appear to be calling from one place while they are actually calling a few feet away.
Much remains to be learned about the ecology and distribution of frogs and toads in Mississippi. The ranges of several species need clarification, and basic life history information is lacking for many. Some of the species represented here appear to be declining. The reasons for this need to be determined, and appropriate conservation measures should be implemented to retain these singing amphibians as part of Mississippi's natural heritage.
The arrangement of the species accounts that follow is in the same sequence as the calls on the tape. The scientific name of the frog or toad is listed after its common name. A short description giving body size of adults and a physical sketch of the species follows. Body size is measured from the tip of the snout to the end of the trunk and does not include the extended rear legs. Known or supposed distribution in Mississippi is followed by dates of breeding, calling sites, and by a rough description of the voice of the species. The comments section lists other species which were calling at the same time that a particular species was recorded along with the location where the recording was made. In most cases the referenced species is producing the most dominant sound in that particular recording. However, if confusion arises, refer to the section on voice for that particular species and the comments section to determine what other species are in the background.
The information in these accounts is intended to be general in nature and is from the sources listed at the end of the accounts or from personal experience. For more complete information on the biology of these species and on amphibians in general, consult the suggested references below.