2025/01/31 by Trevor A. Branch · 2 voices · 1 citation
Environmental Science · Earth and Planetary Sciences · Biochemistry, Genetics and Molecular Biology · #Marine animal studies overview #Underwater Acoustics Research #Animal Vocal Communication and Behavior
paper · doi:10.1111/mms.13228
Abstract Killer whales regularly attack and kill baleen whales, especially their calves. In response, slow‐moving maneuverable “fight” species defend their calves in winter aggregations in predictable shallow coastal locations; while fast‐swimming “flight” species flee on contact and typically disperse in winter across deep open waters. Male singing also differs between fight and flight groups, with fight species producing more intricate songs to win group competitions, while flight species produce loud, monotonous songs to attract distant females. Fight species rely more on group defense and have less need to hide acoustically, but loud‐singing flight species might draw in predatory killer whales. Since killer whales cannot detect sounds <100 Hz and can detect only loud tones below 1500 Hz, singing at low frequencies would result in acoustic crypsis. A review of baleen whale calling frequencies and source levels reveals that although all species are capable of acoustic crypsis, most fight populations produce calls >1500 Hz (24 of 27, 89%), unlike flight populations (12 of 49, 24%). Furthermore, flight species with higher frequency calls produced lower source level calls, greatly reducing detection distances. Thus, flight species may call at low frequencies not only for long‐distance communication but also to avoid detection by killer whales.