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DTSTART:20150327T193000Z
DTEND:20150327T203000Z
SUMMARY:Dr John Ratcliffe
DESCRIPTION:Convergent evolution of a flexible acoustic field of view: echolocation attack sequences in bats and whales



John Ratcliffe, PhD
Assistant Professor
University of Toronto (Mississauga)



Host: Yack lab



Abstract:  Toothed whales and bats are the only animals to use sonar to detect and track prey and the demands of prey capture are positively related to biosonar sophistication. Both groups are known to adjust emitted sound intensity, auditory sensitivity and signal emission rate in response to changing spatial relationships with targets. We have recently demonstrated that in bats superfast laryngeal muscles, rather than perceptual constraints, as previously argued, limit maximum echolocation call rate during the terminal phase of an attack (i.e. limit but power the buzz). We have also found that bats are able to optimize their acoustic field of view to the bestsuit habitat and task. Most recently, we have shown that toothed whales also broaden their biosonar beam
during the buzz, but unlike echolocating bats, maintain the ability to change beamwidth within this terminal phase. Despite the independent evolution of echolocation in whales and bats, and vastly different means of sound generation and transmission, both groups have evolved mechanisms to rapidly update their auditory scene and to change their acoustic FOV over the course of attack. These convergences suggest that the buzz and beam-breadth flexibility have been important drivers in the evolution of echolocation for prey tracking.



Acoustics - Echolocation - Mammals
LOCATION:4440Q Carleton Technology and Training Centre, Carleton University, 1125 Colonel By Dr, Ottawa, ON K1S 5B6
URL:
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