Humpback whales – Ecology & Acoustics

Studies of whale song, non-song calls and feeding super-groups

Each year, thousands of  humpback whales gather off in the Southern Benguela off the west coast of South Africa during spring and summer.  This low latitude feeding ground provides researchers (and the public) a unique opportunity to observe and study the feeding behaviour Southern Hemisphere humpback whales outside the Southern Ocean.

Off South Africa these whales engage in what appears to be a unique feeding behaviour – that of forming dense aggregations of 100s of individuals, all feeding for hours on end.  These groups of very vocally active.  Our research on humpback whales in South Africa and Namibia covers a wide range of aspects but falls under three main themes:

Vocalisation behaviour:  we are using a range of methods to record the song and non-song vocalisations of humpback whales in South Africa and Namibia.  Indications are that whales from both the east and west coasts may be mixing in this feeding ground.  We are investigating the structure of the song recorded over the year to provide insight into this question.  Non-song (or social) calls are far less well studied than humpback whale song.  We are building up a repertoire of non-song calls and linking them to whale behaviour with the aim of being able to understand vocal communication within these large groups, cultural transmission of calls and to be able to better use passive acoustic monitoring to study whale movement over large areas.

Population Structure:  We collect biopsies for genetics and photographs of individuals off Namibia and South Africa to investigate population parameters like abundance, seasonality and movements.

Human Impacts: Through a range of contracts and self-motivated studies we are working to understand the interactions of whales with aquaculture, trap fisheries and shipping around the Western Cape. When feeding in super-groups whales are often very close to shipping channels and do not respond strongly to passing vessels.  There is a high chance of extensive damage occurring to both human life and whales in the event of a ship running through a feeding group of 10s or 100s of whales

 

Humpback whale song – recorded in False Bay, South Africa

 

African BioAcoustics

Sea Search started the African Bioacoustics Community and the Associated Conference(s) to build relationships between researchers in the region.

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