Can threatened species adapt in restored habitat? No expected evolutionary response in lay date for the New Zealand hihi

Many bird species have been observed shifting their laying date to earlier in the year in response to climate change. However the vast majority of these studies were performed on non-threatened species, less impacted by reduced genetic diversity (which is expected to limit evolutionary response) as a consequence of genetic bottlenecks, drift and population isolation. Here we study the relationship between lay date and fitness, as well as its genetic basis, to understand the evolutionary constraints on phenology faced by threatened species using a recently reintroduced population of the endangered New Zealand passerine, the hihi (Notiomystis cincta). A large discrepancy between the optimal laying date and the mode of laying date creates a strong selection differential of -11.24. The impact of this discrepancy on fitness is principally mediated through survival of offspring from hatchling to fledgling. This discrepancy does not seem to arise from a difference in female quality or a trade-...

诸多鸟类已被观测到为响应气候变化而将产卵期提前至每年更早的时段。然而，此类研究的绝大多数均以无危物种为对象，这类物种受遗传多样性降低的影响相对较小——而遗传多样性降低由遗传瓶颈、遗传漂变及种群隔离所致，且被认为会限制物种的演化响应。本研究以新近重新引入野外的濒危新西兰雀形目鸟类——鞍背鸦（hihi，*Notiomystis cincta*）种群为研究对象，探究产卵期与适合度（fitness）之间的关联及其遗传基础，以期阐明濒危物种所面临的物候学（phenology）演化限制机制。最优产卵期与产卵期众数之间存在显著偏差，由此产生的选择差达-11.24。该偏差对适合度的影响主要通过雏鸟至离巢幼鸟的存活率介导实现。而该偏差似乎并非由雌性个体质量差异或繁殖权衡（trade-off）所致……