Patch time allocation and patch sampling by foraging great and blue tits
Patch time allocation and patch sampling by foraging great and blue tits
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DOI：
10.1006/anbe.1999.1380
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发表时间：
2000-05-01
期刊：
影响因子：
2.5
通讯作者：
Naef-Daenzer, B
中科院分区：
文献类型：
--
作者：
Naef-Daenzer, B
父母提供能量的速度是鸟类繁殖的一个重要因素，因为营养不良导致的不良状况可能会降低后代的繁殖存活率。中心位置觅食模型预测，筑巢父母应该优化他们的猎物交付率，最大限度地减少旅行距离，并通过选择补丁，每单位成本的收益是高的。我调查了分配的搜索时间之间的食物补丁在家庭范围内的繁殖大山雀，裤子大，蓝山雀P. caeruleus，通过无线电跟踪。个体树的位置密度与树内猎物生物量呈正相关，与树距巢的距离呈负相关。这两个因素解释了鸟类搜索时间分配的52%的方差。在丰富的补丁，食物大大减少在20米的巢，和鸟类的旅行距离显着增加在雏鸟期。在选择性地在鸟巢附近丰富的资源中觅食的同时，这些鸟不断地在它们的领地内的树木中取样。如果鸟类专门使用最有利可图的补丁，由于资源勘探的平均剩余搜索时间是预期搜索时间的1.52倍（范围1.25-1.99）。尽管相当大的努力，在补丁采样，每单位猎物的整体搜索时间是30%，比预期的同等使用的树木。结果表明，觅食山雀父母接近最大速率的猎物交付可能在一个给定的补丁分布。(C)2000年，动物行为研究协会。
The rate at which parents deliver energy to their brood is an important factor in avian reproduction because poor condition caused by malnutrition may reduce the offspring's survival to breeding. Models of central place foraging predict that nesting parents should optimize their prey delivery rate by minimizing travelling distances and by selecting patches where the gain per unit cost is high. I investigated the allocation of searching time amongst food patches in the home ranges of breeding great tits, Pants major, and blue tits P. caeruleus, by radiotracking. The density of locations in individual trees was positively correlated with prey biomass within trees and negatively with the distance of the trees from the nest. These two factors explained 52% of the variance in the allocation of the birds' search time. In rich patches, food was reduced considerably within 20 m of the nests; and the birds' travelling distances increased significantly during the nestling period. In parallel to foraging selectively in rich resources near the nest, the birds continually sampled the trees in their territory. The average surplus search time due to resource exploration was 1.52 times (range 1.25-1.99) the expected search time if the birds had exclusively used the most profitable patch. Despite considerable effort in patch sampling, the overall search time per unit prey was 30% better than expected by an equal use of trees. The results suggest that foraging tit parents come close to the maximum rate of prey delivery possible in a given patch distribution. (C) 2000 The Association for the Study of Animal Behaviour.