Sexual dimorphism in thick-billed murres, Uria lomvia
The pattern of sexual dimorphism in thick-billed murres, Uria lomvia, from the Lancaster Sound – Jones Sound region, Northwest Territories, was examined for weight and 21 skeletal characters. Univariate statistics (Bonferroni-corrected t-tests) indicated that males were significantly larger than fem...
| Published in: | Canadian Journal of Zoology |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1993
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z93-048 http://www.nrcresearchpress.com/doi/pdf/10.1139/z93-048 |
| Summary: | The pattern of sexual dimorphism in thick-billed murres, Uria lomvia, from the Lancaster Sound – Jones Sound region, Northwest Territories, was examined for weight and 21 skeletal characters. Univariate statistics (Bonferroni-corrected t-tests) indicated that males were significantly larger than females in 6 bill and skull characters. Multivariate statistics also indicated that males had larger bills and skulls than females (based on canonical discriminant analysis), but males were not larger than females in overall body size (as defined by the first principal-components axis). The direction and magnitude of dimorphism were consistent with a hypothesis based on sexual selection as the driving force. In particular, large bill and skull sizes in males are consistent with agonistic behaviours associated with male–male competition for breeding sites and mate guarding. |
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