Sexual dimorphism in wolves ( Canis lupus ) of the Keewatin District, Northwest Territories, Canada
Twenty-two skeletal, visceral, and adipose parameters were compared in 425 wolves collected from the central Arctic between 1987 and 1989. Fifteen parameters differed significantly by sex. Males were usually larger than females; however, the degree of sexual dimorphism varied with structure. Male sk...
Published in: | Canadian Journal of Zoology |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1996
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Subjects: | |
Online Access: | http://dx.doi.org/10.1139/z96-081 http://www.nrcresearchpress.com/doi/pdf/10.1139/z96-081 |
Summary: | Twenty-two skeletal, visceral, and adipose parameters were compared in 425 wolves collected from the central Arctic between 1987 and 1989. Fifteen parameters differed significantly by sex. Males were usually larger than females; however, the degree of sexual dimorphism varied with structure. Male skeletal parameters ranged between 3 and 6% greater than those of females, and significant differences were largely associated with the anterior body region and the limbs. Male body mass was 18% and male visceral parameters ranged between 12 and 24% heavier than those of females. Patterns of adipose deposition were also significantly different. Sternum and inguinal fat depths and total external and mesentery fat indices were significantly greater in males (5–44%), while rump fat depth was significantly greater in females (1%). These results support the conclusion that sexual dimorphism in wolves has evolved primarily as a foraging strategy, owing to division of labour between the sexes, and males are more highly specialized for capturing and killing large ungulate prey, while females are more specialized for a nurtural role. |
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