Composition and Growth of King Eider Ducklings in Relation to Egg Size
Abstract In several bird species, offspring from larger eggs survive better than birds from smaller eggs, but mechanisms responsible for that pattern have not been clearly identified. Studies of waterfowl have found relationships between egg size, body composition of hatchlings, and duckling growth....
| Published in: | The Auk |
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| Main Authors: | , |
| Other Authors: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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Oxford University Press (OUP)
2002
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1093/auk/119.1.62 http://academic.oup.com/auk/article-pdf/119/1/62/29687359/auk0062.pdf |
| Summary: | Abstract In several bird species, offspring from larger eggs survive better than birds from smaller eggs, but mechanisms responsible for that pattern have not been clearly identified. Studies of waterfowl have found relationships between egg size, body composition of hatchlings, and duckling growth. Therefore, body composition and growth rate of newly hatched King Eider (Somateria spectabilis) ducklings were measured to assess if traits consistent with higher probability of survival early in duckling varied in relation to egg size. Forty-one King Eider eggs were collected in June and July 1998 from two lakes in the central Canadian Arctic, and artificially incubated, of which 34 hatched. Body composition of 15 hatchlings (<1 day old) was determined, and 19 ducklings were raised in captivity to measure growth rate. Larger eggs produced larger ducklings with absolutely more lipid and protein reserve; absolutely larger breast and leg muscles; higher functional maturity for whole body, leg, and breast muscles; and higher tarsal growth rates than ducklings from small eggs. Such patterns of hatchling composition and growth in relation to increasing egg size may improve likelihood of early survival by improving thermogenesis, reducing time spent as optimal prey size for avian predators, and as shown elsewhere, by enhancing motor performance of ducklings through improvements in foraging efficiency and predator evasion. |
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