Acoustic communication in the Asian elephant, Elephas maximus maximus
Existing knowledge of acoustic communication in elephants is based primarily on African species (Loxodonta africana and Loxodonta cyclotis). There has been comparatively less study of communication in Asian elephants (Elephas maximus). In order to provide a basis for understanding the evolution and function of acoustic communication in proboscideans, I present a quantitative description of vocal communication in wild Asian elephants. I classify calls by acoustic features into 8 'single' calls, 5 'combination' calls and one possibly unique male call for a total of at least 14 distinct call types. Some of these vocalizations have never before been described. Certain low-frequency calls are individually distinct. Acoustic signals occur in a wide range of social contexts, with some differences in call production among age and sex classes.