Püttmanns Manuel, Böttges Laura, Filla Tim, Lehmann Franziska, Martens Annika Sophie, Siegel Friederike, Sippel Anna, von Bassi Marlene, Balkenhol Niko, Waltert Matthias, Gottschalk Eckhard
Department of Conservation Biology Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology University of Göttingen Göttingen Germany.
Institute for Medical Biometry and Bioinformatics Heinrich Heine University Düsseldorf Düsseldorf Germany.
Ecol Evol. 2022 Jan 26;12(1):e8461. doi: 10.1002/ece3.8461. eCollection 2022 Jan.
Reduced food availability during chick raising is a major driver of farmland bird declines. For the Eurasian Skylark (), food availability is determined by various factors (i.e., arthropod abundance/diversity, accessibility of the vegetation, distance to foraging sites). In modern farmland, it is supposed to decrease over the breeding season due to less penetrable vegetation. We explored foraging habitat selection by chick-raising Skylarks with a focus on the seasonal dynamics of habitat use and food availability. We investigated (i) habitat selection concerning prey biomass/diversity, vegetation cover, and distance to foraging sites, (ii) the overall and seasonal habitat use, and (iii) seasonal developments of foraging parameters (e.g., the feeding frequency) as indicators of food availability. We collected data on foraging habitats and foraging parameters of chick-raising Skylark pairs at 51 nests from a Central European population in 2018 and 2019. Prey biomass/diversity and vegetation cover were measured for all habitats around 42 of these nests. As revealed by multivariate and compositional analyses, Skylarks mainly selected foraging habitats based on the proximity to nests. The most frequent habitats within home ranges could not be ranked according to an overall importance for foraging and their use partially changed over time. The feeding frequency increased throughout the breeding season, while other foraging parameters did not show significant changes. In contrast to our expectations, our data indicated therefore an increase, not a decrease in food availability in the late breeding season. This also implies that the way in which Skylarks used habitats was constantly suitable to raise offspring. We interpret this to be a consequence of the heterogeneous farmland composition of the study area that enabled Skylarks to establish a diverse home range and to benefit from the synergetic effects of neighboring habitat types. Thus, our findings provide support for the high importance of crop diversity in Skylark conservation.
育雏期间食物供应减少是农田鸟类数量下降的主要驱动因素。对于云雀（Alauda arvensis）而言，食物供应由多种因素决定（即节肢动物的丰富度/多样性、植被的可进入性、到觅食地点的距离）。在现代农田中，由于植被穿透性降低，预计其在繁殖季节会减少。我们以育雏云雀的觅食栖息地选择为研究对象，重点关注栖息地利用和食物供应的季节动态。我们调查了：（i）关于猎物生物量/多样性、植被覆盖度以及到觅食地点距离的栖息地选择；（ii）整体和季节性的栖息地利用情况；（iii）作为食物供应指标的觅食参数（如进食频率）的季节性变化。我们于2018年和2019年在中欧一个种群的51个鸟巢处收集了育雏云雀对的觅食栖息地和觅食参数数据。对其中42个鸟巢周围的所有栖息地测量了猎物生物量/多样性和植被覆盖度。多变量和成分分析表明，云雀主要根据离巢的距离选择觅食栖息地。家域内最常使用的栖息地无法根据觅食的总体重要性进行排序，且其使用情况部分会随时间变化。进食频率在整个繁殖季节增加，而其他觅食参数没有显著变化。与我们的预期相反，我们的数据表明繁殖后期食物供应增加而非减少。这也意味着云雀利用栖息地的方式始终适合养育后代。我们认为这是研究区域农田组成异质性的结果，这种异质性使云雀能够建立多样化的家域并从相邻栖息地类型的协同效应中受益。因此，我们的研究结果支持了作物多样性在云雀保护中的高度重要性。
