Colony size and not nest density drives reproductive output in the Common Tern Sterna hirundo
Colony size and not nest density drives reproductive output in the Common Tern Sterna hirundo
复制标题
群体规模而非巢穴密度决定着普通燕鸥的繁殖产出
作者：
K. Szostek;P. Becker;Bertie Meyer;S. Sudmann;H. Zintl
众所周知，密度是人口规模调节的一个重要因素。已经在群体鸟类中发现了几种密度限制机制。我们研究了普通燕鸥的竞争，以评估限制繁殖产量的因素是否是对巢穴的竞争（取决于当地的巢穴密度），还是对食物资源的密度依赖性竞争（取决于使用相同觅食区域的总体群体规模）。我们发现，在三个不同栖息地（一个海洋，两个淡水）的五个普通燕鸥群落中，群落大小和巢穴密度与繁殖产出之间存在很强的关联。基于巢密度不同的 Banter See 群体的六个独立亚群体的详细长期数据集，我们发现繁殖成功与巢密度无关，而是与群体整体规模相关，这可能是资源枯竭和食物竞争的结果。我们还发现饲养过程中蜂群大小对雏鸟后返回率的影响。这些结果对于旨在恢复减少的燕鸥数量的保护管理计划具有重要意义。
Density is known to be an important factor in population size regulation. Several mechanisms of density limitation have been identified in colonial birds. We studied competition in Common Terns Sterna hirundo to assess whether the factor limiting reproductive output was competition for nest-sites, which is dependent on local nest density, or density-dependent competition for food resources, which is dependent on overall colony size using the same foraging area. We found strong associations of both colony size and nest density with reproductive output in five colonies of Common Terns in three different habitats (one marine, two freshwater). Based on detailed long-term datasets of six separate sub-colonies of the Banter See colony that differed in nest density, we found that reproductive success was not related to nest density but to overall colony size, possibly a result of resource depletion and food competition. We also found carry-over effects of colony size during rearing on post-fledging return rate. These results have important implications for the conservation management plans aimed at recovering declining populations of Common Terns.