Vocal activity of tropical dolphins is inhibited by the presence of killer whales, Orcinus orca
Article first published online: 18 OCT 2012
2012 by the Society for Marine Mammalogy Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Marine Mammal Science
Volume 29, Issue 4, pages 679–690, October 2013
How to Cite
Rankin, S., Archer, F. and Barlow, J. (2013), Vocal activity of tropical dolphins is inhibited by the presence of killer whales, Orcinus orca. Marine Mammal Science, 29: 679–690. doi: 10.1111/j.1748-7692.2012.00613.x
- Issue published online: 9 OCT 2013
- Article first published online: 18 OCT 2012
- Manuscript Accepted: 28 JUL 2012
- Manuscript Received: 28 OCT 2011
- killer whales;
- dolphin behavior;
- acoustic behavior;
- predator avoidance
Research has suggested killer whale (Orcinus orca) predation may affect cetacean vocal behavior; however, few data exist to test this hypothesis. Data collected during 40,976 km of visual and acoustic shipboard surveys in the tropical Pacific Ocean, including 1,232 detections of 13 species, were examined to determine if changes in dolphin vocal activity could be attributed to the presence of killer whales. Generalized linear models and Random Forest analyses were used to test the hypothesis that dolphin vocal activity was related to the distance and time to the nearest killer whale sighting. Both results show that dolphin vocalizations were inversely correlated with the temporal proximity of killer whales (P < 0.05). Despite the relative rarity of killer whales in the tropics, they appear to influence vocal behavior of nearby dolphin schools. This disruption in communication may not significantly impact interactions necessary for survival in tropical waters where killer whale density is low. However, in temperate climates, where increased productivity supports a greater abundance of killer whales, this interruption in communication may have a greater impact. The lower incidence of whistling dolphins in temperate waters may be related to the greater abundance of killer whales in these areas.