Songs of humpback whales (Megaptera novaeangliae. off Antarctica and South Africa

Abstract

Seasonal acoustic occurrences and diel singing patterns of humpback whale (Megaptera novaeangliae. songs are described using acoustic recordings from the west coast of South Africa and Maud Rise, Antarctica. Acoustic data were recorded using autonomous acoustic recorders deployed on oceanographic moorings from early 2014 to early 2017. Acoustic occurrences (i.e. presences. of humpback whale songs were identified through visual scrutiny of spectrograms of recorded data. Environmental parameters associated with humpback whale song occurrences were identified and ranked according to their model-predicted relative importance. In South Africa, humpback whale songs were detected from June to December with peaks in the occurrence of song in September. In Antarctica, humpback whale songs were detected from March to May (singing peaked in April. with few songs detected in July and September. Humpback whales were more vocally active at night in all recording sites. Peaks of acoustic occurrence of humpback whale songs in spring and autumn for South Africa and Antarctica respectively, suggest the west coast of South Africa is potentially used as an overwintering ground and migratory route whereas the Maud Rise is possibly used as a feeding ground. This study improves our knowledge about the diel singing pattern and seasonal occurrence of humpback whale songs off the west coast of South Africa and the Maud Rise, Antarctica. Such knowledge could be essential for the conservation and management of the species in South Africa and Antarctica. - Abstract as displayed in the - Abstract booklet. The presentation on the day may differ from the - Abstract.