Animal vocalizations studied

WASHINGTON, Aug. 26 (UPI) -- An American Psychological Association report finds a number of ways that animals can adapt vocal calls depending on social situations.

A special August issue of the Journal of Comparative Psychology entitled "Acoustic Interaction in Animal Groups: Signaling in Noisy and Social Contexts," offers a variety of findings from the natural world that are described in a Monday press release.

Included are results such as male, gray treefrogs giving out longer but fewer mating calls around other males. In effect, a male seeking female attention will change the rhythm of his call to break out of the chorus. Another study found although dolphins whistle more in social situations, individual dolphins decrease vocal output in large groups when their whistles are more likely to be drowned out. Similarly, tree swallows in the nest adjust their call output to parents when facing noisy competition from the brood.

"Pooling data on vocal imitation, vocal convergence and compensation for noise suggests a wider (cross-species) distribution of vocal production learning among mammals than has been generally appreciated," said Peter Tyack, a biologist at the Woods Hole Oceanographic Institution, concluding it could mean mammals have more capacity for learning to vocalize than previously thought.