Department of Life Sciences and Systems Biology, Turin University, via Accademia Albertina 13, 10123, Turin, Italy.
Société de la Flore Valdôtaine, via J. B. de Tillier 3, 11100, Aosta, Italy.
Sci Rep. 2023 Nov 27;13(1):20908. doi: 10.1038/s41598-023-46336-0.
Climate change is affecting the alpine ecosystem at an unprecedented rate, with marked changes in spring phenology and the elevation distribution of birds. Changes in the European Alps are happening rapidly, and it is possible behaviours stand to change from one year to the next. The year 2022 was characterised by climatic extremes: Italy experienced its hottest year ever, and it was the driest since 1800. Here, we assessed whether the foraging ecology of two coexisting upland bird species, the yellow-billed and the red-billed chough, changed from 2021 to 2022. We assessed foraging stay times, flock size, propensity to mixed flocking, foraging home ranges and altitudinal distribution. Stay times of both species when foraging in monospecific flocks significantly shortened in 2022, especially in the case of the red-billed chough. The two corvids are known to influence each other when foraging together. In 2021, as expected, the stay times of the red-billed chough decreased when in the presence of the congener, but this did not occur in 2022. Instead, the yellow-billed chough increased its altitudinal foraging distribution in 2022. The results are in line with the hypothesis that large climate variations may disrupt the foraging ecology of mountain birds. However, as it is not possible to draw solid conclusions from just two years of observations, further field research will have to be planned in the future.
气候变化正以前所未有的速度影响高山生态系统，导致春季物候和鸟类海拔分布发生明显变化。欧洲阿尔卑斯山的变化正在迅速发生，鸟类的行为可能会在一年内发生变化。2022 年的特点是气候极端：意大利经历了有史以来最热的一年，也是自 1800 年以来最干旱的一年。在这里，我们评估了两种共存的高山鸟类——黄嘴山鸦和红嘴山鸦的觅食生态学是否在 2021 年至 2022 年间发生了变化。我们评估了觅食停留时间、鸟群大小、混合觅食倾向、觅食活动范围和海拔分布。两种雀形目鸟类在单一种群中觅食时的停留时间在 2022 年明显缩短，尤其是红嘴山鸦。众所周知，这两种鸦科动物在觅食时会相互影响。在 2021 年，正如预期的那样，红嘴山鸦的停留时间随着同种鸟类的出现而减少，但在 2022 年并没有发生这种情况。相反，黄嘴山鸦在 2022 年增加了其在海拔较高处的觅食分布。研究结果符合这样一种假设，即较大的气候变化可能会扰乱高山鸟类的觅食生态学。然而，由于仅从两年的观测中不可能得出确凿的结论，未来还需要计划进行进一步的实地研究。
