Dear MARMAM members, On behalf of my co-authors I am pleased to announce our new publication on pilot whale biosonar in The Journal of the Acoustical Society of America.
Pedersen, M. B., Tønnesen, P., Malinka, C. E., Ladegaard, M., Johnson, M., Aguilar de Soto, N., and Madsen, P. T. (2021). Echolocation click parameters of short-finned pilot whales (Globicephala macrorhynchus) in the wild The Journal of the Acoustical Society of America 149, 1923-1931, https://doi.org/10.1121/10.0003762 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. The article is available from the Journal of Acoustical Society of America at https://doi.org/10.1121/10.0003762 If you do not have access to the pdf, please do not hesitate to contact me. Best regards, Michael Bjerre Pedersen, PhD Student Marine Bioacoustics Lab<http://www.marinebioacoustics.com> Zoophysiology, Dept. Biology Aarhus University C.F. Møllers Allé 3, Building 1131 8000 Aarhus C, Denmark Email: michael.peder...@bio.au.dk<mailto:michael.peder...@bio.au.dk> Twitter: @michael_bjerre_<https://twitter.com/michael_bjerre_>
_______________________________________________ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
