Proximate drivers of spatial segregation in non-breeding albatrosses.
Proximate drivers of spatial segregation in non-breeding albatrosses.
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DOI：
10.1038/srep29932
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发表时间：
2016-07-21
影响因子：
4.6
通讯作者：
Phillips RA
中科院分区：
文献类型：
--
作者：
Clay TA;Manica A;Ryan PG;Silk JR;Croxall JP;Ireland L;Phillips RA
许多动物划分资源以避免竞争，在殖民地繁殖的物种中，这通常导致空间或栖息地的使用分散。在非繁殖季节，觅食限制放松，但种群之间和种群内部隔离的模式和驱动因素却知之甚少。我们建立了栖息地偏好模型，研究了外在因素（栖息地可用性和种内竞争）和内在因素（种群、性别和繁殖结果）如何影响非繁殖灰头信天翁（Thalassarche chrysostoma）的分布，追踪了两个主要种群，南乔治亚岛（大西洋）和爱德华王子群岛（印度洋）。空间隔离大于预期，反映了生境选择和可达性的明显季节性差异，避免了与当地育种者的种内竞争。先前失败的鸟类在夏季与成功的鸟类在空间上隔离，当它们使用生产力较低的水域时，这表明繁殖结果与随后的栖息地选择之间存在联系。相比之下，我们发现性别隔离的证据很弱，这并不能反映栖息地使用的差异。研究结果表明，信天翁分布的大尺度空间结构是内外因素相互作用的结果，对种群动态具有重要意义。由于不同种群对栖息地的偏好有很大差异，在确定需要保护的关键区域时，应独立考虑种群。
Many animals partition resources to avoid competition, and in colonially-breeding species this often leads to divergent space or habitat use. During the non-breeding season, foraging constraints are relaxed, yet the patterns and drivers of segregation both between and within populations are poorly understood. We modelled habitat preference to examine how extrinsic (habitat availability and intra-specific competition) and intrinsic factors (population, sex and breeding outcome) influence the distributions of non-breeding grey-headed albatrosses Thalassarche chrysostoma tracked from two major populations, South Georgia (Atlantic Ocean) and the Prince Edward Islands (Indian Ocean). Spatial segregation was greater than expected, reflecting distinct seasonal differences in habitat selection and accessibility, and avoidance of intra-specific competition with local breeders. Previously failed birds segregated spatially from successful birds during summer, when they used less productive waters, suggesting a link between breeding outcome and subsequent habitat selection. In contrast, we found weak evidence of sexual segregation, which did not reflect a difference in habitat use. Our results indicate that the large-scale spatial structuring of albatross distributions results from interactions between extrinsic and intrinsic factors, with important implications for population dynamics. As habitat preferences differed substantially between colonies, populations should be considered independently when identifying critical areas for protection.