sounds emitted by animals and used as a means of intraspecies, more rarely interspecies, communication, or for purposes of echolocation. They are characteristic of many insects, fish, and acaudate amphibians; some reptiles (gekkos, chameleons, crocodiles); and almost all species of birds and mammals.
Animal sounds in a broad sense also include sonic reactions of animals emitted not only by the voice apparatus but also by the swim bladder and fins (fish), tailfeathers (snipe), wings (ruffed grouse), beak (woodpecker, stork), and special apparatus on the legs and wings (orthopterous insects) or abdominal area (cicada). In insects and amphibians, sonic reactions are principally species-identification signals during the reproductive period. In fish, in addition, they may signify danger or alarm. The most diverse sounds are emitted by birds and monkeys. Thus songbirds, besides singing, produce more than 20 sonic reactions that express fear, hunger, and alarm, as well as warnings to fledglings. The complete diversity of sounds emitted by animals has not as yet been studied. An example of interspecies animal communication are the cries of the honey-guide birds, who draw the attention of the honey badger. The ultrasounds characteristic of bats and dolphins and the sounds within the range of human hearing produced by some birds (oilbird, salangane swift) that nest in dark caves have echolocational significance.
A. S. MAL’CHEVSKII