Title

The Expression of Affect in African Elephant (Loxodonta africana) Rumble Vocalizations

Grant Title

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

Document Type

Article

Publication Date

5-2009

Source Publication

Journal of Comparative Psychology

Source ISSN

0735-7036, 1939-2087

Abstract

Affective states are thought to be expressed in the mammalian voice, but such investigations are most common in primates. Source and filter features of rumbles were analyzed from 6 adult female African elephants (Loxodonta africana) at Disney’s Animal Kingdom. Rumbles produced during periods of minimal social interaction (“low affect”) were compared to those produced during dominance interactions (“high affect”). Low-ranking females produced rumbles with increased and more variable fundamental frequencies, and increased durations and amplitudes during dominance interactions with superiors, compared to the low affect context. This acoustic response is consistent with the expression of affect in mammals and may signal submission to superiors. The 2 highest ranking females were codominant and competed for alpha status. They produced rumbles with decreased and less variable fundamental frequencies, increased durations and amplitudes, and a decrease in formant dispersion during dominance interactions with each other, compared to the low affect context. This response is not generally consistent with the expression of affect, but may signal large body size to competitors. These results suggest that affect can be expressed in the voiced sounds of elephants.

Document Rights and Citation of Original

Journal of Comparative Psychology, Vol. 123, No. 2 (May 2009): 222-225. DOI.