Click Detection Rate Variability of Central North Pacific Sperm Whales From Passive Acoustic Towed Arrays
April 01, 2024
Understanding the factors affecting their click rates provides important information for acoustic density estimation.
Passive acoustic monitoring (PAM) is an optimal method for detecting and monitoring cetaceans as they frequently produce sound while underwater. Cue counting, counting acoustic cues of deep-diving cetaceans instead of animals, is an alternative method for density estimation, but requires an average cue production rate to convert cue density to animal density.
Limited information about click rates exists for sperm whales in the central North Pacific Ocean. In the absence of acoustic tag data, we used towed hydrophone array data to calculate the first sperm whale click rates from this region and examined their variability based on click type, location, distance of whales from the array, and group size estimated by visual observers.
Our findings show click type to be the most important variable, with groups that include codas yielding the highest click rates.
Barkley YM, Merkens KPB, Wood M, Oleson EM, Marques TA 2024. Click detection rate variability of central North Pacific sperm whales from passive acoustic towed arrays J Acoust Soc Am.155(4):2627-2635.
10.1121/10.0025540. PMID: 38629884.