Extreme diversity in the songs of Spitsbergen's bowhead whales

Abstract

Almost all mammals communicate using sound, but few species produce complex songs. Two baleen whales sing complex songs that change annually, though only the humpback whale (Megaptera novaeangliae) has received much research attention. This study focuses on the other baleen whale singer, the bowhead whale (Balaena mysticetus). Members of the Spitsbergen bowhead whale population produced 184 different song types over a 3-year period, based on duty-cycled recordings from a site in Fram Strait in the northeast Atlantic. Distinct song types were recorded over short periods, lasting at most some months. This song diversity could be the result of population expansion, or immigration of animals from other populations that are no longer isolated from each other by heavy sea ice. However, this explanation does not account for the within season and annual shifting of song types. Other possible explanations for the extraordinary diversity in songs could be that it results either from weak selection pressure for interspecific identification or for maintenance of song characteristics or, alternatively, from strong pressure for novelty in a small population.

Encouraging encounters: unusual aggregations of bowhead whales Balaena mysticetus in the western Fram Strait

“…A tagged female bowhead tracked by Lydersen et al (2012) associated mainly with open water, never occurred in areas with ice cover above 65% and was recorded 180 km from the ice-edge. Off Svalbard, bowhead whales occupy areas deep within the pack-ice during winter, as discovered based on acoustic data (Stafford et al 2012(Stafford et al , 2018. The affiliation between bowhead whales and sea-ice has also been explored off West Greenland: whales in that area preferred high ice cover (> 65%) with thick first-year ice and open water (Ferguson et al 2010).…”

Acoustic detection of the critically endangered North Pacific right whale in the northern Bering Sea

“…, Stafford et al . ). Neverthless, upsweeps are one of the most common call types of bowhead whales (Clark and Johnson , Blackwell et al .…”

“…Bowhead whales are endemic to the Arctic, occurring in the northern Bering Sea primarily during winter and spring months for breeding (December-May; Rugh et al 1993, W€ ursig and Clark 1993, Noongwook et al 2007, Citta et al 2015. Bowhead song occurs on migration and during the presumed winter/spring breeding season; it is characterized by multiple short songs, often with repetitive, high frequency (up to 5 kHz) complex frequency modulation (Delarue et al 2009, Stafford et al 2018. Neverthless, upsweeps are one of the most common call types of bowhead whales (Clark and Johnson 1984, Blackwell et al Thompson et al 1986), 10 September 2016.…”

Acoustic detections of Arctic marine mammals near Ulukhaktok, Northwest Territories, Canada

“…Data from satellite tagging can provide good spatial and temporal coverage, but sample size can be very small (Hauser et al 2014;Citta et al 2015). Passive acoustic monitoring has been effectively used throughout the Arctic to study long-term trends in marine mammal distribution (Hannay et al 2013;Jones et al 2014;Clark et al 2015;Stafford et al 2018). We therefore used passive acoustic monitoring to examine patterns in marine mammal presence near Ulukhaktok, Northwest Territories, from October 2016 through April 2017.…”