Vocal activity of tropical dolphins is inhibited by the presence of killer whales, Orcinus orca

TitleVocal activity of tropical dolphins is inhibited by the presence of killer whales, Orcinus orca
Publication TypeJournal Article
Year of Publication2013
AuthorsRankin S., Archer F., Barlow J
JournalMarine Mammal Science
Date Published2013/10
Type of ArticleArticle
ISBN Number0824-0469
Accession NumberWOS:000325482800021
Keywordsacoustic behavior; behavior; communication; context; dolphin behavior; evolution; killer whales; mammals; predation; predator avoidance; signals; tursiops-truncatus; vocalizations; whistle

Research has suggested killer whale (Orcinus orca) predation may affect cetacean vocal behavior; however, few data exist to test this hypothesis. Data collected during 40,976km 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.

Short TitleMar. Mamm. Sci.
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