Department of Biology, Queen's University, Kingston, ON, Canada.
Applied Sciences, Skills, and Technology, Loyalist College, Belleville, ON, Canada.
Oecologia. 2020 Mar;192(3):713-722. doi: 10.1007/s00442-020-04618-8. Epub 2020 Feb 25.
Population decline and the threat of extinction are realities currently facing many species. Yet, in most cases, the detailed demographic data necessary to identify causes of population decline are unavailable. Using 43 years (1975-2017) of data from a box-nesting population of tree swallows (Tachycineta bicolor), we identified reduced survival of offspring as a probable demographic cause of population decline. Poor fledging success was associated with increased predation and poor weather conditions during early nestling development. Low juvenile survival and subsequent recruitment was linked to poor weather conditions during the post-fledging period and may also be linked to conditions on the wintering grounds. Regional weather conditions during critical stages of breeding (early nestling and post-fledging) have become progressively worse over the 43-year study period. None of the other factors linked to offspring survival have similarly deteriorated. Overall, our results suggest tree swallows should be added to the growing list of species challenged by climate change, and that other species of aerial insect specialists may face similar impacts of climate change.
人口减少和灭绝的威胁是许多物种目前面临的现实。然而，在大多数情况下，缺乏确定人口减少原因所需的详细人口数据。利用 43 年来（1975-2017 年）来自树燕（Tachycineta bicolor）的箱巢种群的数据，我们确定了后代存活率降低是种群减少的一个可能的人口统计学原因。较差的育雏成功率与捕食增加和早期巢雏发育期间恶劣天气条件有关。低幼鸟存活率和随后的补充与育雏后阶段恶劣天气条件有关，也可能与越冬地的条件有关。在繁殖的关键阶段（早期巢雏和育雏后）期间，区域天气条件在 43 年的研究期间变得越来越差。与后代存活率相关的其他因素都没有类似的恶化。总的来说，我们的研究结果表明，树燕应该被列入受到气候变化挑战的物种名单，而其他的空中昆虫专家物种可能面临着类似的气候变化影响。
