Dorsal fin scars as indicators of age, sex, and social status in humpback whales ( Megaptera novaeangliae)

We compared the number of linear marks and the shapes of dorsal fins of different classes of humpback whales during the breeding season. Male humpbacks tend to have more marks than females. Such marks are probably scars resulting from physical contact during intrasexual competition for mates. Not al...

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Bibliographic Details
Published in:Canadian Journal of Zoology
Main Authors: Chu, Kevin, Nieukirk, Sharon
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1988
Subjects:
Online Access:http://dx.doi.org/10.1139/z88-059
http://www.nrcresearchpress.com/doi/pdf/10.1139/z88-059
Description
Summary:We compared the number of linear marks and the shapes of dorsal fins of different classes of humpback whales during the breeding season. Male humpbacks tend to have more marks than females. Such marks are probably scars resulting from physical contact during intrasexual competition for mates. Not all males have marks; therefore, an unmarked adult humpback could be a male or a female. An adult with many marks is likely a male, however. Differences in the dorsal fins of principal and secondary escorts in large groups of competing males suggest that not all escorts have the same chance of attaining principal escort status. Therefore, male – male competitions in large groups should not necessarily be viewed as contests between equals. Principal escorts showed significantly more of some types of marks than did lone escorts of cows with calves, suggesting that not all lone escorts may retain their position if challenged.