Sound production and behaviour of humpback whales (Megaptera novaeangliae) on feeding grounds in NE-Icelandic waters
The humpback whale is a migratory species which possesses a complex sound repertoire. This ranges from simple non-song sounds, referred to as social sounds, to complex mating songs. Non-song sounds have been reported on their feeding and breeding grounds. There is a considerable lack of understanding about the role of these non-song sounds due to relatively few publications, especially from high latitude feeding grounds. The aim of this research is to gain better understanding on the role of these social sounds on a high latitude feeding ground. The sound behaviour was studied in relation to their visually observed behaviour, on summer feeding grounds, NE-Iceland. Passive acoustic recordings and video recordings of surface behaviour were conducted simultaneously. The study periods were July - August 2012, and June – July 2013.A custom made hydrophone was used during the earlier period at a depth of 8.5 m, and a Reson hydrophone during the latter period at depths of 15 m and 20 m. The observation of each humpback whale, video commentary, whale ID from footage, and GPS of each sampling sequence, were combined to get a clear assessment of the behaviour of the observed whales. Each detected vocalization will be inspected visually and aurally, using a spectrogram in the Raven Pro sound analysis software. All that combined has the purpose of getting synchronized behaviour and acoustic results, for sound associated behaviour.