Infrasound from the Okapi

Presented Feb.6-11 1992

American Association for the Advancement of Science (AAAS)

158th Conference - invited presentation Student competition award

Elizabeth von Muggenthaler

Old Dominion University

 

Abstract

 

The okapi, an endangered, forest dwelling giraffid

possessing limited auditory vocalizations, produces copious infrasounds. Recordings were made of ten okapia Johnstoni at the San Diego Wild Animal Park In Escondido, California, and White Oak Plantation in Yulee,Florida. A Bruel and Kjaer recording system and a portable DAT recorder, Genrad microphones, and portable oscilloscope were used and the results studied using an Onosoki CF920 spectrum analyzer.

Frequencies of the infrasonic calls ranged from 9 to 70 hertz. Infrasonic communication correlates with the large-eared, heavynecked anatomical characteristics of the okapis and with their life style as rare, solitary, partially nocturnal animals living in dense habitats. The recognition that okapis, like elephants, whales and possibly rhinoceroses, may communicate at these low frequencies supports the hypothesis that many large mammals transmit information with Infrasound to a degree heretofore unappreciated.