Volume (Issue #):
A study was conducted with humpback whales to test their response to recordings of conspecific social sounds and an artificially generated tone stimulus. Experiments were conducted during humpback whales southward migration along the east coast of Australia. A total of 13 tone experiments, 15 social sound experiments and 3 silent controls were conducted during two field seasons (September/October 2004 and 2008). The results indicated that humpback whales respond differently, with respect to course traveled and dive strategy, to the two stimuli. Humpback whales responded to 'tones' by moving offshore and surfacing more often, perhaps trying to avoid the stimuli. These changes were related to the proximity to the source, the received signal level and signal to signal noise ratio. When social sounds were used the responses were very variable and dependent on the groups composition. This study indicates that behavioral responses of marine mammals to acoustic stimuli is complex and in need of additional research.