Frozen verses: Antarctic minke whales (Balaenoptera bonaerensis) call predominantly during austral winter --data_minke

The recent identification of the bio-duck call as Antarctic minke whale
(AMW) vocalization allows the use of passive acoustic monitoring to
retrospectively investigate year-round spatial- temporal patterns in minke
whale occurrence in ice-covered areas. Here, we present an analysis of AMW
occurrence patterns based on a 9-year passive acoustic dataset (2008–
2016) from 21 locations throughout the Atlantic sector of the Southern
Ocean (Weddell Sea). AMWs were detected acoustically at all mooring
locations from May to December, with the highest presence between August
and November (bio-duck calls present at more than 80% of days). At the
southernmost recording locations, the bio-duck call was present up to 10
months of the year. Substantial inter-annual variation in the seasonality
of vocal activity correlated to variation in local ice concentration. Our
analysis indicates that part of the AMW population stays in the Weddell
Sea during austral winter. The period with the highest acoustic presence
in the Weddell Sea (September–October) coincides with the timing of the
breeding season of AMW in lower latitudes. The bio-duck call could
therefore play a role in mating, although other behavioural functions of
the call cannot be excluded to date.