Rushing Clark S, Ryder Thomas B, Marra Peter P
Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA.
Proc Biol Sci. 2016 Jan 27;283(1823). doi: 10.1098/rspb.2015.2846.
Worldwide, migratory species are undergoing rapid declines but understanding the factors driving these declines is hindered by missing information about migratory connectivity and the lack of data to quantify environmental processes across the annual cycle. Here, we combined range-wide information about migratory connectivity with global remote-sensing data to quantify the relative importance of breeding and non-breeding environmental processes to persistent long-term population declines of a migratory songbird, the wood thrush (Hylocichla mustelina). Consistent with theoretical predictions about population limitation of migratory birds, our results suggest that habitat loss and climate have contributed to the observed declines in wood thrush breeding abundance, yet the relative importance of breeding versus non-breeding factors is population-specific. For example, high-abundance core breeding populations appear to be more limited by habitat loss, whereas low-abundance, peripheral populations appear to be limited by climate-driven seasonal interactions. Further, our analysis indicates that the relative impact of breeding habitat loss is at least three to six times greater than the impact of equivalent non-breeding habitat loss and therefore the steepest regional declines have likely been driven by the loss of breeding habitat. These results underscore the need for population-specific conservation strategies implemented throughout the annual cycle to reverse long-term declines.
在全球范围内，迁徙物种数量正在迅速减少，但由于缺乏关于迁徙连通性的信息以及量化全年环境过程的数据，阻碍了我们对导致这些减少的因素的理解。在此，我们将关于迁徙连通性的广泛信息与全球遥感数据相结合，以量化繁殖和非繁殖环境过程对一种迁徙鸣禽——伍德 Thrush（Hylocichla mustelina）长期种群持续减少的相对重要性。与关于候鸟种群限制的理论预测一致，我们的结果表明，栖息地丧失和气候导致了观察到的伍德 Thrush 繁殖数量的下降，然而繁殖因素与非繁殖因素的相对重要性因种群而异。例如，高丰度的核心繁殖种群似乎更多地受到栖息地丧失的限制，而低丰度的边缘种群似乎受到气候驱动的季节性相互作用的限制。此外，我们的分析表明，繁殖栖息地丧失的相对影响至少比同等非繁殖栖息地丧失的影响大三到六倍，因此最严重的区域下降可能是由繁殖栖息地的丧失驱动的。这些结果强调了需要在全年实施针对特定种群的保护策略，以扭转长期下降趋势。
