Kujala Inga, Pöysä Hannu, Korpimäki Erkki
Department of Environmental and Biological Sciences University of Eastern Finland Joensuu Finland.
Section of Ecology, Department of Biology University of Turku Turku Finland.
Ecol Evol. 2024 Mar 12;14(3):e11155. doi: 10.1002/ece3.11155. eCollection 2024 Mar.
Agricultural intensification and climate change are serious threats toward animal populations worldwide. Agricultural intensification reduces the heterogeneity of agricultural habitats by diminishing crop variation and destroying microhabitats, such as small woody features, whereas the effects of climate change range from the growing frequency of weather extremes to disrupted prey-predator dynamics. We collected long-term ringing data from a population of Eurasian kestrels () located amidst agricultural areas in western Finland during 1985-2021, which we combined with density indices of their main prey species (voles), spatial data consisting of land cover classification of kestrel territories, and weather data, to study the effects of different environmental drivers on breeding density and success. We found that the density of inhabited nests rose with vole abundance and springtime snow depth, with the overall trend of population growth being stronger in areas with more heterogeneous landscapes. Clutch size was influenced negatively by the age of male parent and landscape heterogeneity, and positively by vole abundance, with rainfall having a negative influence conditional to other variables. Likewise, the number of produced fledglings was affected by male age, but it was additionally positively associated with landscape heterogeneity and its interaction with rainfall, with greater fledgling output in heterogeneous landscapes during high precipitation. The discrepancy between factors predicting large clutches and high numbers of fledglings suggests that while kestrels do not prefer heterogeneous landscapes when prospecting for territories, heterogeneous habitats provide better circumstances for foraging during the nestling period, which ensures nestling survival, particularly during adverse environmental conditions. Therefore, breeding in areas under intense agricultural use is more suboptimal to kestrels than their territory preferences would indicate. As changing climate may reduce prey availability and heighten the probability of weather extremities, agricultural intensification may lead to weaker reproductive success in densely populated farmland habitats.
农业集约化和气候变化对全球动物种群构成严重威胁。农业集约化通过减少作物多样性和破坏诸如小树木特征等微生境，降低了农业栖息地的异质性，而气候变化的影响范围从极端天气频率的增加到猎物 - 捕食者动态关系的破坏。我们收集了1985 - 2021年期间位于芬兰西部农业区的欧亚红隼种群的长期环志数据，并将其与主要猎物物种（田鼠）的密度指数、由红隼领地土地覆盖分类组成的空间数据以及气象数据相结合，以研究不同环境驱动因素对繁殖密度和繁殖成功率的影响。我们发现，有巢居住的密度随田鼠数量和春季积雪深度增加而上升，在景观更具异质性的地区，种群增长的总体趋势更强。窝卵数受到雄性亲鸟年龄和景观异质性的负面影响，受到田鼠数量的正面影响，降雨在其他变量条件下具有负面影响。同样，出飞雏鸟的数量受雄性年龄影响，但还与景观异质性及其与降雨的相互作用呈正相关，在高降水量期间，异质性景观中的雏鸟产出更高。预测大窝卵数和高雏鸟数量的因素之间的差异表明，虽然红隼在寻找领地时不偏好异质性景观，但异质栖息地在育雏期提供了更好的觅食条件，这确保了雏鸟的存活，特别是在不利的环境条件下。因此，在农业高强度利用地区繁殖对红隼来说比其领地偏好所显示的更不理想。由于气候变化可能减少猎物的可获得性并增加极端天气的可能性，农业集约化可能导致人口密集的农田栖息地繁殖成功率降低。
