Dear MARMAM community We are very happy to announce that our new paper on the echo scene of a sperm whale has been published. Using dtags, we have for the first time recorded prey echoes from a hunting sperm whale, showing that the whale uses long-range echolocation and encounters several hundred prey items per dive of which less than 10 % are targeted for capture. The paper is accessible here: https://royalsocietypublishing.org/doi/10.1098/rsbl.2020.0134 We hope you will find the paper interesting and are happy to answer any question you might have (please contact pernill...@bio.au.dk).
On behalf of all authors Pernille Tønnesen ABSTRACT Sperm whales use their gigantic nose to produce the most powerful sounds in the animal kingdom, presumably to echolocate deep-sea prey at long ranges and possibly to debilitate prey. To test these hypotheses, we deployed sound recording tags (DTAG-4) on the tip of the nose of three sperm whales. One of these recordings yielded over 6000 echo streams from organisms detected up to 144 m ahead of the whale, supporting a long-range prey detection function of the sperm whale biosonar. The whale navigated this complex acoustic scene by maintaining a stable, long-range acoustic gaze suggesting continual resource evaluation. Less than 10% of the echoic organisms recorded by the tag were targeted for capture and only 18% of the buzzes were emitted within the 50 m depth interval of maximum organism encounter rate, demonstrating echo-guided prey selection. Buzzes were initiated more than 20 m from the prey, showing that sperm whales do not debilitate their prey with sound, but trade echo levels for reduced forward masking and rapid updates on prey location in keeping with the lower manoeuvrability of these large predators. We conclude that the powerful biosonar of sperm whales enables long-range echolocation and selection of prey, but not acoustic debilitation.
_______________________________________________ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
