Mysterious bio-duck sound attributed to the Antarctic minke whale (Balaenoptera bonaerensis)

Abstract

For decades, the bio-duck sound has been recorded in the Southern Ocean, but the animal producing it has remained a mystery. Heard mainly during austral winter in the Southern Ocean, this ubiquitous sound has been recorded in Antarctic waters and contemporaneously off the Australian west coast. Here, we present conclusive evidence that the bio-duck sound is produced by Antarctic minke whales (Balaenoptera bonaerensis). We analysed data from multi-sensor acoustic recording tags that included intense bio-duck sounds as well as singular downsweeps that have previously been attributed to this species. This finding allows the interpretation of a wealth of long-term acoustic recordings for this previously acoustically concealed species, which will improve our understanding of the distribution, abundance and behaviour of Antarctic minke whales. This is critical information for a species that inhabits a difficult to access sea-ice environment that is changing rapidly in some regions and has been the subject of contentious lethal sampling efforts and ongoing international legal action.

The marine soundscape of the Perth Canyon

“…Vocalizations believed to be the ''bioduck'' sound of Antarctic minke whales (Risch et al, 2014) were detected during July and August. Fig.…”

Review of Underwater and In-Air Sounds Emitted by Australian and Antarctic Marine Mammals

“…Antarctic mine whales also emit bouts of rapid broadband pulses (which are brief FM downsweeps), sounding like a duck's quack (named the "bioduck" sound). This unique "bioduck" sound has been recorded in Antarctica and off Australia for decades, yet it was not until Risch et al [49], that this sound was positively attributed to Antarctic minke whales. The "bioduck" sound contains pulses of 0.1-0.4-s duration, in bouts of 5-12 pulses, with a 1-3-s interval between bouts, and source levels of 140.2 ± 3.6 dB re 1 µPa rms @ 1 m [49,51].…”

“…Although some individuals might remain in Antarctica over the winter [47]. In Antarctica, FM downsweeps with a fundamental of 60-140 Hz, occurring with and without harmonics, with a duration of 0.2 ± 0.1 s and a source level of 147.3 ± 5.3 dB re 1 µPa rms @ 1 m have been recorded [48][49][50][51]. Antarctic mine whales also emit bouts of rapid broadband pulses (which are brief FM downsweeps), sounding like a duck's quack (named the "bioduck" sound).…”

Description and seasonal detection of two potential whale calls recorded in the Indian Ocean

“…Across other oceans, minke whales are known to produce a range of sounds including pulses, clicks, downsweeps, and a variety of other frequency-modulated sounds (e.g., boing, "star wars," and "bio-duck" signals) (e.g., Beamish and Mitchell, 1973;Edds-Walton, 2000;Mellinger et al, 2000;Gedamke et al, 2001;Rankin and Barlow, 2005;Oswald et al, 2011;Risch et al, 2013;Risch et al, 2014). It has been suggested that pulses, the star-wars signals, and boings may act as song.…”