Changes in humpback whale singing behavior with abundance: Implications for the development of acoustic surveys of cetaceans

• Published in: The Journal of the Acoustical Society of America
• Main Authors: Noad, Michael J., Dunlop, Rebecca A., Mack, Amelia K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: AIP Publishing 2017
• Subjects: Blainvilles Beaked-Whales; Megaptera-Novaeangliae; Location System; West-Indies; Air Gun; Accuracy; Noise; Song; Communication; Migration; 1201 Arts and Humanities (miscellaneous); 3102 Acoustics and Ultrasonics; Humpback Whale; Megaptera novaeangliae
• Online Access: https://espace.library.uq.edu.au/view/UQ:692426

Acoustic surveys of vocal animals can have significant advantages over visual surveys, particularly for marine mammals. For acoustic density estimates to be viable, however, the vocal output of the animals surveyed needs to be determined under a range of conditions and shown to be a robust predictor of abundance. In this study, the songs of humpback whales, one of the most vocal and best studied species of marine mammals, were tested as predictors of abundance. Two acoustic metrics, the number of singing whales and amount of songs produced, were compared with the number of whales seen traversing a study site on the eastern coast of Australia over an 18 year period. Although there were predictive relationships between both metrics and numbers of passing whales, these relationships changed significantly as the population grew in size. The proportion of passing whales that sang decreased as the population increased. Singing in humpback whales, therefore, is a poor predictor even of relative abundance and illustrates the caution required when developing acoustic survey techniques particularly when using social vocalizations. (C) 2017 Acoustical Society of America.