Body mass regulation in response to changes in feeding predictability and overnight energy expenditure
Body mass regulation in response to changes in feeding predictability and overnight energy expenditure
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DOI：
10.1093/beheco/11.2.189
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发表时间：
2000-03-01
影响因子：
2.4
通讯作者：
Jones, EKM
中科院分区：
文献类型：
--
作者：
Cuthill, IC;Maddocks, SA;Jones, EKM
喂养和脂肪储存既需要成本，也需要收益。好处包括最大限度地减少饥饿的风险;成本包括运动和捕食风险的质量依赖性成本。对这些成本和收益的理解不仅与觅食模式和脂肪储存的解释有关，而且与囤积决策，迁移策略和种群动态有关。尽管有理论模型的预测，但对模型的假设和预测的实证检验只是最近才得到检验。然而，已发表的实验的不可预测性的影响往往混淆操纵的平均值，变异性和可预测性的食物供应，所有这些都被预测影响觅食强度和脂肪储存。在对欧洲椋鸟Sturnus vulgaris的实验中，我们操纵了食物供应的可预测性，同时保持平均值和平均变异性不变。我们通过模拟夜间风暴露来操纵夜间能量消耗。更大的不可预测性的食物供应和更高的夜间能量消耗增加每日体重增加和黄昏（瘦肉和脂肪）的质量，但在一个纯粹的添加剂的方式。黎明的质量只改变了可预测性，而不是一夜之间的能量消耗。通过引入一个探测日，所有处理的喂养经验相同，我们确定了对可预测性的反应是基于超过一天的经验。
Feeding and fat storage entail both costs and benefits. Benefits include minimizing the risk of starvation; costs include mass-dependent costs of locomotion and predation risk. An understanding of these costs and benefits is relevant not only to explanations of foraging patterns and fat storage, but to hoarding decisions, migration strategies, and population dynamics. Despite predictions from theoretical models, empirical tests of the assumptions and predictions of models have been tested only recently. However, published experiments on the effects of unpredictability have often confounded manipulations of mean, variability, and predictability of the food supply, all of which are predicted to affect foraging intensity and fat storage. In experiments on European starlings, Sturnus vulgaris, we manipulated the predictability of the food supply while holding the mean and average variability constant. We did this in conjunction with manipulation of overnight energy expenditure via simulated nocturnal wind exposure. Both greater unpredictability of food availability and higher overnight energy expenditure increased daily mass gain and dusk (lean and fat) mass, but in a purely additive fashion. Dawn mass only changed in response to predictability, not overnight energy expenditure. By introducing a probe day, with identical feeding experience for all treatments, we ascertained that the response to predictability was based on experience integrated over more than a single day.