British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
Department of Archaeology, Max Planck Institute for the Science of Human History, Kahlaische Strasse 10, 07745, Jena, Germany.
Sci Rep. 2021 Nov 11;11(1):22133. doi: 10.1038/s41598-021-01506-w.
The rapidly changing climate in the Arctic is expected to have a major impact on the foraging ecology of seabirds, owing to changes in the distribution and abundance of their prey but also that of competitors (e.g. southerly species expanding their range into the Arctic). Species can respond to interspecific competition by segregating along different niche axes. Here, we studied spatial, temporal and habitat segregation between two closely related seabird species: common guillemot Uria aalge (a temperate species) and Brünnich's guillemot Uria lomvia (a true Arctic species), at two sympatric sites in Iceland that differ in their total population sizes and the availability of marine habitats. We deployed GPS and temperature-depth recorders to describe foraging locations and behaviour of incubating and chick-rearing adults. We found similar evidence of spatial segregation at the two sites (i.e. independent of population sizes), although segregation in environmental space was only evident at the site with a strong habitat gradient. Unexpectedly, temporal (and, to a limited extent, vertical) segregation appeared only at the least populated site. Overall, our results show complex relationships between the levels of inferred competition and that of segregation.
北极地区迅速变化的气候预计将对海鸟的觅食生态产生重大影响，这是由于其猎物的分布和丰度发生了变化，但也由于竞争物种（例如，向南扩展其分布范围进入北极的物种）的变化。物种可以通过沿着不同的生态位轴进行隔离来应对种间竞争。在这里，我们在冰岛的两个共生地点研究了两种密切相关的海鸟：普通海鸠 Uria aalge（一种温带物种）和 Brünnich 的海鸠 Uria lomvia（一种真正的北极物种），这两个地点在总种群数量和海洋栖息地的可利用性方面存在差异。我们部署了 GPS 和温度深度记录器来描述处于孵卵和育雏阶段的成年海鸟的觅食地点和行为。我们发现，在这两个地点都存在类似的空间隔离证据（即，与种群数量无关），尽管在具有强烈栖息地梯度的地点才明显存在环境空间隔离。出乎意料的是，仅在人口最少的地点才出现时间（并且在一定程度上是垂直）隔离。总的来说，我们的研究结果表明，推断的竞争程度与隔离程度之间存在复杂的关系。
