Parental roles of male and female thick-billed murres and razorbills at the Gannet Islands, Labrador
We studied female and male parental roles in two sympatric auks, thick-billed murre (Uria lomvia) and razorbill (Alca torda), with initial biparental care at the breeding site and later exclusively paternal care at sea. Our study addressed the following two questions: Why do males accompany chicks t...
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| Format: | Text |
| Language: | English |
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2006
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.523.583 http://www.mun.ca/serg/BEH24721.pdf |
| Summary: | We studied female and male parental roles in two sympatric auks, thick-billed murre (Uria lomvia) and razorbill (Alca torda), with initial biparental care at the breeding site and later exclusively paternal care at sea. Our study addressed the following two questions: Why do males accompany chicks to sea?, and How do the sexes allocate parental effort at the breeding site before parental care at sea begins? We tested the hypothesis that males care for chicks at sea because they are in better condition at the time of chick departure as a result of female-biased parental effort at the breeding site (‘nest’). Breeding success and duration of chick-rearing did not differ between the two study years in either species at the Gannet Islands, Labrador. At the breeding colonies, females of both species provided more food (murres: 2.84 ± 0.18 loads day−1; razorbills: 2.02 ± 0.11 loads day−1) to their chicks than males (murres: 2.26±0.12 loads day−1; razorbills: 1.42±0.09 loads day−1), and males spent more time brooding the chicks. These differences were chick-age dependent in both species, with females providing more meals to chicks older than two weeks. Razorbill males spent more time with chicks greater than two weeks old, while murre male’s attentiveness of brooding did not vary with chick age. In both species, males (murres: 3.04 ± 0.3 h day−1; razorbill: |
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