Food Supply and Hatching Spans of Birds: Energy Constraints or Facultative Manipulation
Food Supply and Hatching Spans of Birds: Energy Constraints or Facultative Manipulation
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鸟类的食物供应和孵化期：能量限制或兼性操纵
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
G. Bortolotti
中科院分区：
文献类型：
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作者：
K. Wiebe;G. Bortolotti
晚成鸟的孵化通常需要数小时或数天的时间。人们提出了许多假设来解释孵化异步性，但大多数实验都集中在雏鸟阶段，以确定一些孵化后的好处，例如增加繁殖成功率。我们把注意力集中在前期的近因上，但这些近因在很大程度上被忽视了。在萨斯喀彻温省北部，我们在早春对猎物物种（小型哺乳动物）进行了普查，并测量了 4 年多来 273 窝美洲红隼 (Falco sparverius) 的异步情况。孵化异步性通过两种方式进行量化：一窝内所有蛋孵化的时间和雏鸟之间的质量等级。在食物丰沛的年份，一窝幼崽的孵化时间比食物匮乏的年份更加同步。同样，位于良好领地的父母或身体状况良好的雌性比处于食物压力下的父母有更多的同步育雏。在一项实验中，我们在产蛋前期给红隼补充食物。接受补充的父母产下更大的蛋，并且更同步地孵化这些蛋，但对照组在将幼崽养育到羽翼未丰的阶段方面更成功。食物丰富时的同步孵化符合与雏鸟食物供应有关的孵化跨度的兼性操纵假说，但与能量约束假说不同。
Clutches of altricial birds generally hatch over a period of hours or days. Numerous hypotheses have been generated to explain hatching asynchrony, but most experiments have focused on the nestling stage to determine some post—hatch benefit such as increased reproductive success. We concentrated on proximate causes in the prelaying period, which have largely been ignored. In northern Saskatchewan, we censused prey species (small mammals) in early spring and measured the asynchrony of 273 clutches of the American Kestrel (Falco sparverius) over 4 yr. Hatching asynchrony was quantified in two ways: time for all the eggs within a clutch to hatch and mass hierarchies among nestlings. In good food years, the hatchling spans of clutches were more synchronous than in poor years. Similarly, parents on good territories or females in good physical condition had more synchronous broods than parents under food stress. In an experiment, we supplemented food to kestrels during the prelaying period. Parents that were supplemented laid larger eggs and hatched those eggs more synchronously, but control pairs were more successful at raising young to the fledging stage. Synchronous hatching when food is abundant is consistent with the hypothesis of facultative manipulation of hatching spans in relation to nestling food supply, but not with the energy constraint hypothesis.