ARCTK Phenotypic Variation,among Thick-billed Murres from Colonies in Hudson Strait.
ABSTRACT. Thick-billed Murres (Uria.hvio) breeding in the Canadian Arctic are restricted to a small number of colonies, all comprising more than 10 OOO pairs. Five of these colonies are scattered through Hudson Strait. We collected adult breeders at three of the colonies- Digges Island, Hantzsch Isl...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.596.8205 http://pubs.aina.ucalgary.ca/arctic/Arctic37-3-284.pdf |
| Summary: | ABSTRACT. Thick-billed Murres (Uria.hvio) breeding in the Canadian Arctic are restricted to a small number of colonies, all comprising more than 10 OOO pairs. Five of these colonies are scattered through Hudson Strait. We collected adult breeders at three of the colonies- Digges Island, Hantzsch Island, and Akpatok Island- and compared wing and bill measurements and body weights to look for intercolony differences. Significant intercdony differences were present for all measurements and a discriminant function analysis showed that sane individuals fall compleley outside the rangeof variation for the other colonies. Because of the presence of the Laurentide ice-sheet over Hudson Strait, the present colony sites could not have been occupied for more than 10 OOO years. If the observed differences reflect differences in genotype then their evolution must have occurred over this perid. Key words: Thick-billed Murre, Uria lomvia, phenotypic variation, Hudson Strait, evolution R&SUMfi. Les Marmettes de Brunnich (Vria lomvia) nichent dans I’arctique canadien et sont r6parties dans un petit nombre de colonies de 10 OOO couples et plus. Cinq de ces colonies se retrouvent dam le dhroit d’Hudson. Nous avons collectionne des adultes dans trois de ces colonies: lles Dig-ges, Hantzsch et Akpatok. Nous avons cornpar6 les mesures de la longueur de l’aile et du bec ainsi que les poids pour verifier s’il y avait des differences entre les colonies. Nous avons observe des differences significatives.entre.les mesurations et les poids des trois colonies et I’analyse discriminante. nous indique que quciques specimens se situent en dehors des limites de variation des autres colonies. A cause de la p r h n c e du glacier Laurentien sur le d b i t d’Hudson durant la dernibre glaciation, I’occupation des sites actuels par la Marmette de Brunnich daterait d’environ 10 OOO am. Si.les.diff6rences observeeS traduisent des genotypes differem, leur evolution se serait produite B I’interieur de cette p&iode. Mots clb: Ma- de Brunnkh, Uria ... |
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