EFFECTS OF HATCHING DATE AND EGG SIZE ON GROWTH, RECRUITMENT, AND ADULT SIZE OF LESSER SCAUP
EFFECTS OF HATCHING DATE AND EGG SIZE ON GROWTH, RECRUITMENT, AND ADULT SIZE OF LESSER SCAUP
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孵化日期和卵大小对小鱼的生长、补充和成年体型的影响
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
R. Clark
中科院分区：
文献类型：
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作者：
R. Dawson;R. Clark
有证据表明，在季节早期繁殖或产下较大蛋的鸟类具有选择优势，因为它们后代的质量和存活率较高。我们测试了野生小鲷（Aythya affinis）孵化在本赛季初或从较大的鸡蛋有增强的增长，小鸭和更大的尺寸或更高的概率招募到当地的繁殖人口在孵化后的几年。在捕获年龄校正后，体重，头长，和culmen的雏鸭孵化日期呈负相关，但不相关的蛋体积。作为成年人，晚孵化的鸟类有较短的翅膀长度（仅二年级的鸟类），并往往有较小的头部长度（所有孵化后一年的鸟类）比早孵化的鸟类。我们认为，后期孵化的鸟类是较小的，由于增加了对食物的竞争，在育雏饲养。纳塔尔蛋体积的增加和纳塔尔孵化日期较晚的鸟类之间的下降，招聘概率增加。我们推测这些结果是由于从小蛋孵化的小鸭死亡率较高，因为早期孵化的鸟类有更多的时间获得营养储备，这将减少对迁移成本的脆弱性。
Abstract Evidence suggests that birds breeding early in the season or laying larger eggs are at a selective advantage because quality and survival of their offspring are higher. We tested whether wild Lesser Scaup (Aythya affinis) hatching early in the season or from larger eggs had enhanced growth as ducklings and larger size or higher probability of recruiting to the local breeding population in years after hatching. After correcting for age at capture, body mass, head length, and culmen of ducklings were inversely related to hatching date, but were unrelated to egg volume. As adults, late-hatched birds had shorter wing lengths (second-year birds only) and tended to have smaller head lengths (all after-hatch year birds) than early hatching birds. We suggest that later-hatching birds are smaller due to increased competition for food during brood rearing. Recruitment probability increased as natal egg volume increased and decreased among birds with later natal hatching dates. We speculate these results are due to higher mortality of ducklings hatched from small eggs, and because early-hatched birds have more time to acquire nutrient reserves that would reduce vulnerability to costs of migration.