Department of Geography, University of Wisconsin-Milwaukee , WI , USA.
Centre for the Environment, Trinity College Dublin , Dublin , Ireland.
PeerJ. 2015 Jan 15;3:e726. doi: 10.7717/peerj.726. eCollection 2015.
There have been many recent reports across Europe and North America of a change in the timing of arrival and departure of a range of migrant bird species to their breeding grounds. These studies have focused primarily on passerine birds and climate warming has been found to be one of the main drivers of earlier arrival and departure in spring. In Ireland, rising spring temperature has been shown to result in the earlier arrival of sub-Saharan passerine species and the early departure of the Whooper Swan. In order to investigate changes in spring arrival and departure dates of waterbirds to Ireland, we extracted latest dates as an indicator of the timing of departure of winter visitors (24 species) and earliest dates as an indicator of the timing of arrival of spring/summer migrants (2 species) from BirdWatch Ireland's East Coast Bird reports (1980-2003). Three of the winter visitors showed evidence of later departure and one of earlier departure whereas one of the spring/summer visitors showed evidence of earlier arrival. In order to determine any influence of local temperature on these trends, we analysed data from two synoptic weather stations within the study area and found that spring (average February, March and April) air temperature significantly (P < 0.05) increased at a rate of 0.03 °C per year, which was strongly correlated with changes in latest and earliest records. We also tested the sensitivity of bird departure/arrival to temperature and found that Northern Pintail would leave 10 days earlier in response to a 1 °C increase in spring temperature. In addition, we investigated the impact of a large-scale circulation pattern, the North Atlantic Oscillation (NAO), on the timing of arrival and departure which correlated with both advances and delays in departure and arrival. We conclude that the impact of climate change on earliest and latest records of these birds is, as expected, species specific and that local temperature had less of an influence than large-scale circulation patterns.
近年来，欧洲和北美的许多研究报告都指出，一系列候鸟到达和离开繁殖地的时间发生了变化。这些研究主要集中在雀形目鸟类上，气候变暖被认为是春季提前到达和离开的主要驱动因素之一。在爱尔兰，春季温度上升导致撒哈拉以南雀形目鸟类更早到达，而大天鹅更早离开。为了调查爱尔兰水鸟春季到达和离开日期的变化，我们从爱尔兰鸟类观察协会的东海岸鸟类报告（1980-2003 年）中提取了最晚到达日期作为冬季访客（24 种）离开时间的指标，以及最早到达日期作为春季/夏季候鸟（2 种）到达时间的指标。其中 3 种冬季访客显示出较晚离开的迹象，1 种显示出较早离开的迹象，而 1 种春季/夏季访客显示出较早到达的迹象。为了确定当地温度对这些趋势的任何影响，我们分析了研究区域内两个天气站的同步气象数据，发现春季（平均 2 月、3 月和 4 月）空气温度以每年 0.03°C 的速度显著（P < 0.05）升高，这与最晚和最早记录的变化密切相关。我们还测试了鸟类离开/到达对温度的敏感性，发现如果春季温度升高 1°C，北方针尾鸭将提前 10 天离开。此外，我们调查了北大西洋涛动（NAO）这一大尺度环流模式对到达和离开时间的影响，发现其与离开和到达的提前和延迟都有关联。我们得出的结论是，气候变化对这些鸟类最早和最晚记录的影响是特定物种的，而当地温度的影响小于大尺度环流模式的影响。
