Foraging effort in relation to the constraints of reproduction in free‐ranging albatrosses
Foraging effort in relation to the constraints of reproduction in free‐ranging albatrosses
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自由放养信天翁的觅食努力与繁殖限制的关系
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
H. Weimerskirch
中科院分区：
文献类型：
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作者：
S. Shaffer;D. Costa;H. Weimerskirch
总结1。理论模型预测，在繁殖过程中，当繁殖限制发生变化时，动物会改变它们的努力，以最大化不同的货币，如时间和能量，但这在自由放养的动物中研究得很少。2. 通过比较流浪信天翁（Diomedea exulans Linnaeus）在孵化期和雏鸟孵化期的质量变化、觅食成本和特定活动行为，考察了觅食努力（单位时间能量）。1998年，38只信天翁（20只在孵化期，18只在孵蛋期）被注射了双重标记的水，并配备了卫星发射机和活动数据记录器。3. 孵育期信天翁的航程是育雏期的3.7倍，出海时间是育雏期的3.2倍，但觅食成本明显低于育雏期（育雏期为4.52∠0.50 SD W kg - 1比育雏期为4.98∠0.55 SD W kg - 1）。4. 在孵育期间，日增重率随出海时间的延长而显著降低，而在育雏期间，日增重率随出海时间的延长而显著增加。5. 在孵蛋期间，觅食的努力更高，这表明鸟类正在尽量减少在海上的时间，以最大限度地提高向雏鸟提供食物的速度。相比之下，孵化期间的觅食努力较低，这表明鸟类在海上的时间最大化，觅食的能量消耗最小化。6. 觅食成本在两性之间也存在差异。然而，这与身体大小的差异有关，而不是像以前的研究表明的那样与觅食努力的差异有关。
Summary 1. Theoretical models predict that animals will vary their effort to maximize different currencies such as time and energy when the constraints of reproduction change during breeding, but this has been poorly studied in free-ranging animals. 2. Foraging effort (energy per unit time) was examined by comparing mass changes, foraging costs and activity-specific behaviours of Wandering Albatrosses ( Diomedea exulans Linnaeus) during the incubation and chick-brooding stages. In 1998, 38 albatrosses (20 during incubation and 18 during brooding) were injected with doubly labelled water and equipped with satellite transmitters and activity data loggers. 3. During incubation, albatrosses travelled 3·7 times farther and were at sea 3·2 times longer, yet foraging costs were significantly lower than trips made during brooding (incubation 4·52 ∠ 0·50 SD W kg - 1 vs brooding 4·98 ∠ 0·55 SD W kg - 1 ). 4. The rate of daily mass gain decreased significantly with time at sea during incubation whereas the rate of daily mass gain increased significantly with time at sea during brooding. 5. Foraging effort was higher during brooding, suggesting that birds were minimizing time at sea to maximize the rate of food delivery to chicks. In contrast, foraging effort was lower during incubation, suggesting that birds were maximizing time at sea and minimizing the energy costs of foraging. 6. Foraging costs were also different between sexes. However, this was related to body size differences and not to differences in foraging effort as suggested in previous studies.