Echolocation click parameters of short-finned pilot whales (Globicephala macrorhynchus) in the wild
Abstract
Short-finned pilot whales (Globicephala macrorhynchus) are large, deep-diving predators with diverse foraging strategies, but little is known about their echolocation. To quantify the source properties of short-finned pilot whale clicks, we made 15 deployments off the coast of Tenerife of a deep-water hydrophone array consisting of seven autonomous time-synced hydrophone recorders (SoundTraps), enabling acoustic localization and quantification of click source parameters. Of 8185 recorded pilot whale clicks, 47 were classified as being recorded on-axis, with a mean peak-to-peak source level (SL) of 181 ± 7 dB re 1 μPa, a centroid frequency of 40 ± 4 kHz, and a duration of 57 ± 23 μs. A fit to a piston model yielded an estimated half-power (–3 dB) beam width of 13.7° [95% confidence interval (CI) 13.2°–14.5°] and a mean directivity index (DI) of 22.6 dB (95% CI 22.5–22.9 dB). These measured SLs and DIs are surprisingly low for a deep-diving toothed whale, suggesting we sampled the short-finned pilot whales in a context with little need for operating a long-range biosonar. The substantial spectral overlap with beaked whale clicks emitted in similar deep-water habitats implies that pilot whale clicks may constitute a common source of false detections in beaked whale passive acoustic monitoring efforts.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 01, 2021
- Source ID
- 10.1121/10.0003762
Entities
People
- Chloë Malinka
- M. Johnson
- Michael B Pedersen
- Michael Ladegaard
- N. Aguilar De Soto
- Pernille Tonnesen
- Peter Teglberg Madsen
Organizations
- Aarhus Universitets Forskningsfond
- Aarhus University
- Marie Skłodowska-Curie Actions
- Office of Naval Research Global