Analysis of humpback whale sounds from the Southern Ocean.

• Main Author: Mueller, Simone
• Format: Thesis
• Language: unknown
• Published: 2017
• Subjects: Antarctic; Southern Ocean; The Antarctic; Greenwich; Antarc*; baleen whale; Humpback Whale; Megaptera novaeangliae
• Online Access: https://epic.awi.de/id/eprint/49002/; https://hdl.handle.net/10013/epic.b14383bc-3259-42cd-b357-68719cb87941

Humpback whales are a highly vocal baleen whale species. Alongside social sounds produced by both sexes, male humpback whales also produce song, which is thought to play a role in reproduction processes during the breeding season. Humpback whales are traditionally thought to seasonally migrate between winter breeding areas in lower latitudes and summer feeding areas in higher latitudes. Evidence of offseason humpback whale (Megaptera novaeangliae) acoustic presence in high latitude feeding areas is accumulating for Northern Hemisphere waters. For the Southern Ocean seasonal patterns in humpback whale vocal behaviour have to date only been investigated for a coastal site. This study provides preliminary year-round baseline data from 2011 from three offshore recording sites on humpback whale vocal behaviour on Antarctic feeding grounds. Passive acoustic recorders were located along a transect from the Greenwich meridian to the Antarctic continent, at 59’S (AWI227- 11_SV0002), at 64’S (AWI229-9_SV1000) and 66’S (AWI230-7_SV1001). Humpback whales were found to be acoustically present from January to August (AWI227- 11_SV0002), from January to June (AWI229-9_SV1000) and from January until May (AWI230-7_SV1001). Acoustic presence was most pronounced (>80% of recording days containing calls) from May to August (AWI227- 11_SV0002), and April to May (AWI229-9_SV1000 and AWI230-7_SV1001) concurring with substantial local increases in ice cover. From January to March acoustic presence was sparser (<35% of recording days containing calls). Calls were divided into 27 call categories with a maximum of 10 subtypes per category. For all three recorders 4 to 8 call categories made up <80% of all calls, three call categories of which were the same for all three recorders. The vocal repertoire was more diverse in March, April and May compared to January, February, June, July and August in all three recorders. Furthermore, humpback whale song was present at all three recording sites, at AWI227- 11_SV0002 in May and June, ...