Habitat-mediated population limitation in a colonial central-place forager: the sky is not the limit for the black-browed albatross
Habitat-mediated population limitation in a colonial central-place forager: the sky is not the limit for the black-browed albatross
复制标题
殖民地中心地区觅食者的栖息地介导的种群限制：天空不是黑眉信天翁的限制
DOI：
--
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Jason Matthiopoulos
中科院分区：
文献类型：
--
作者：
Ewan D. Wakefield;R. Phillips;Jason Matthiopoulos
动物种群经常受到食物或栖息地可获得性的限制。在中心地觅食者，获取这些资源的成本与距离有关，而不是在空间上统一。然而，在海鸟这一被广泛研究的范例中，经验种群模型迄今忽略了这一成本。在一定程度上，这是因为殖民地之间的非独立性使定义人口单位变得困难。在这里，我们模拟了资源可获得性和可获得性对一种广泛分布的远洋海鸟--黑眉信天翁--种群的影响。我们采用多尺度的方法，客观地将区域种群定义为群体的空间集群。我们考虑了两个容易量化的资源可获得性指标：浅海水域范围(首选觅食栖息地)和净初级生产量(NPP)。我们表明，在对可及性进行加权后，区域信天翁种群的大小强烈依赖于栖息地的可获得性，在较小程度上依赖于NPP。我们的结果间接支持了海鸟种群在繁殖季节受到食物供应自下而上调节的假设，并表明食物的时空可预测性可能是有限的。此外，我们还展示了一种简单、广泛适用的方法来估计中心地觅食者种群的资源限制。
Animal populations are frequently limited by the availability of food or of habitat. In central-place foragers, the cost of accessing these resources is distance-dependent rather than uniform in space. However, in seabirds, a widely studied exemplar of this paradigm, empirical population models have hitherto ignored this cost. In part, this is because non-independence among colonies makes it difficult to define population units. Here, we model the effects of both resource availability and accessibility on populations of a wide-ranging, pelagic seabird, the black-browed albatross Thalassarche melanophris. Adopting a multi-scale approach, we define regional populations objectively as spatial clusters of colonies. We consider two readily quantifiable proxies of resource availability: the extent of neritic waters (the preferred foraging habitat) and net primary production (NPP). We show that the size of regional albatross populations has a strong dependence, after weighting for accessibility, on habitat availability and to a lesser extent, NPP. Our results provide indirect support for the hypothesis that seabird populations are regulated from the bottom-up by food availability during the breeding season, and also suggest that the spatio-temporal predictability of food may be limiting. Moreover, we demonstrate a straightforward, widely applicable method for estimating resource limitation in populations of central-place foragers.