Source level measurements of killer whale (Orcinus orca) echolocation clicks

Biosonar is vital to odontocetes (toothed whales, dolphins, and porpoises) for navigation and finding food. Consequently, numerous details of their echolocation click parameters, such as source level and beam width, are known for many species; however, there is a data gap for killer whales (Orcinus orca). This information is essential for examining masking potential which could have an impact on their foraging abilities. The Southern Resident killer whales are an endangered population of orcas living along the Pacific coast of North America and underwater noise has been identified as a major threat towards their survival. This study used a 3D 24-element hydrophone array deployed in close proximity to wild killer whales to estimate source levels (SLs) and spectra of echolocation clicks. Future work will use these SLs to investigate masking potential from current and other noise scenarios.