Echolocation in wild killer whales (Orcinus orca) ...

• Main Author: Barrett-Lennard, Lance
• Format: Text
• Language: English
• Published: University of British Columbia 2008
• Subjects: Orca; Orcinus orca; Alaska
• Online Access: https://dx.doi.org/10.14288/1.0086068; https://doi.library.ubc.ca/10.14288/1.0086068

Echolocation by odontocete whales has been demonstrated in captive settings many times, yet little is known about its use and function in the wild. In this thesis, I describe echolocation sounds in pods of killer whales (Orcinus orca) off the coasts of British Columbia and Alaska. I examine the relationships between echolocation and water clarity, ambient noise, and behavioural activity. I compare echolocation by two populations with different feeding habits and foraging patterns. The study provides new insight into the functional role of odontocete echolocation, and into the relative contributions of vision and passive listening to spatial perception and prey detection. Underwater recordings were made during 111 encounters with killer whales. Known members of the resident (fish-eating) population were photographically identified 85 times, and transients (mammal eaters) 23 times. Click sounds characteristic of echolocation were identified in the recordings aurally, and by spectrographic and waveform ...