Completed Research Project

Title / Titel
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Communication in blue whales (Balaenoptera musculus)
Summary / Zusammenfassung
Of all the ways to transmit information over long distances through the sea, sound is the best and many marine species take advantage of this property. Cetaceans for example rely heavily on sound production and perception for survival. They use it to navigate, detect food and predators, and also to communicate to conspecifics, for example to attract mates or maintain social bonds. Despite the primary role of sound in these activities, the function and use of most vocalisations is unknown. This is particularly true for cosmopolitan, pelagic whale species like blue whales (Balaenoptera musculus) and is mainly due to their difficult accessibility and the lack of knowledge on the behavioural context of sound emission.
Blue whales, which usually swim several kilometres apart, evolved acoustic characteristics that are well adapted for long-range communication. The most common vocalisations of these whales are loud, long, stereotyped infrasonic (8-20Hz) sound sequences that occur more frequently during migrations and winter breeding periods. Although their role is unclear, they may represent male breeding displays (songs) and might contain information on the quality of the singing individual that, as observed in other taxa, is important in mate choice. Due to distinct differences in the structures of the songs between whale populations inhabiting different geographical areas (dialects), we can assign individuals to their specific group. Shorter transient higher-frequency calls (30-200Hz) are associated with feeding and most likely social behaviours, but their function remains largely unknown.
Throughout the last century, noises from human activities (shipping, military sonar, seismic exploration) have dramatically increased ambient oceanic noise level. Most of these activities produce sounds within the same frequency range used by large whales for vocal communication. Disruption of sound production and perception could therefore interfere with most biologically important activities (e.g. finding food or mates) and adversely influence the well-being and productivity of individual animals, and ultimately populations. The study of possible adaptations in response to increasing background noise might help evaluating effects of noise pollution.
The study aims to evaluate the role of different blue whale vocalisations, determine sex and individual differences in their calling behaviour as well as the influence of anthropogenic noise on communication. This research will grow the understanding of acoustic signal function and noise influence in large whales and help determine ecological factors important for their conservation. This is important considering the fact that blue whales are endangered, facing a very high risk of extinction IUCN (Species Survival Commission of the World Conservation Union).
Publications / Publikationen
DI IORIO, L. (2005): Methods to study communication in whales. Cognition, Brain, Behavior, 9 (3): 583-597.
Keywords / Suchbegriffe
animal behaviour, communication, vocalisations, marine mammals, whales, bluewhales, Balaenoptera musculus, noise pollution, anthropgenic noise, conservation
Project Leadership and Contacts /
Projektleitung und Kontakte
Lucia di Iorio, PhD (Project Leader)lucia.diiorio@zool.uzh.ch
Prof. Marta Mansermarta.manser@zool.uzh.ch
Funding Source(s) /
Unterstützt durch
Forschungskredit der Universität Zürich, Others
 
In Collaboration with /
In Zusammenarbeit mit
Prof. Chris Clark, Biocacoustic Lab, Universtiy of Cornell, IthacaSwitzerland

Prof. S. Bengio, IDIAP (Dalle Molle Institute for Perceptual Artificial Intelligence), Martigny

Switzerland

Duration of Project / Projektdauer
Nov 2003 to Aug 2007

© Universität Zürich, 1. September 2007, Impressum