Social organization of humpback whales on a North Atlantic feeding ground
Abstract Data from a long-term study of individually identified humpback whales, Megaptera novaeangliae, were used to describe patterns of association and grouping of this species on one of its principal North Atlantic feeding grounds in the southern Gulf of Maine. Most groups were small and unstabl...
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| Format: | Book Part |
| Language: | English |
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Oxford University PressOxford
1993
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| Online Access: | http://dx.doi.org/10.1093/oso/9780198540694.003.0008 https://academic.oup.com/book/chapter-pdf/52430131/isbn-9780198540694-book-part-8.pdf |
| Summary: | Abstract Data from a long-term study of individually identified humpback whales, Megaptera novaeangliae, were used to describe patterns of association and grouping of this species on one of its principal North Atlantic feeding grounds in the southern Gulf of Maine. Most groups were small and unstable, and individual whales of both sexes and all age classes associated with many conspecifics. Only six instances of stable associations were recorded. Analysis of the class composition of singles and pairs showed that: (1) among singles, juveniles of both sexes were significantly over represented and mature females significantly under-represented; (2) male-female adult pairs were over-represented; (3) adult-juvenile pairs of any gender combination were under-represented; and (4) pairings between adult males were under represented except during feeding. Only 12 of 2690 pairs consisted of animals that were known to be related. It is suggested that the fission-fusion sociality that characterized the study population represents a response to two ecological factors. Firstly, absence of predation nullifies the need for large groups for predator detection or communal defence. Secondly, the spatial characteristics of piscine prey favour a foraging strategy involving frequent changes in group size. In this system, kinship and dominance probably play reduced roles, while the apparent lack of territoriality is typical of taxa confronted by heterogeneously distributed and mobile resources. The apparent preference by mature males for associations with mature females may represent an attempt to establish bonds with potential future mates. |
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