Frozen verses: Antarctic minke whales (Balaenoptera bonaerensis) call predominantly during austral winter --data_minke
Data files
Oct 06, 2020 version files 14.21 KB
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data_AMW.csv
Abstract
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.
Methods
The acoustic data was collected using 21 hydrophones deployed across the Weddell Sea (HAFOs network). Data was collected between 2008 until 2016.
The sea-ice concentration data used for this study were extracted from satellite images with a resolution of 6.25 × 6.25 km from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) satellite sensor ( Spreen G, Kaleschke L, Heygster G. 2008 Sea ice remote sensing using AMSR-E 89-GHz channels. J. Geophys. Res. Ocean. 113, C02S03). (doi:10. 1029/2005JC003384).
Usage notes
The detection values corresponds the number of days with acoustic presence of AMW per month.