Habitat use and foraging parameters of breeding Skylarks indicate no seasonal decrease in food availability in heterogeneous farmland

Reduced food availability during chick raising is a major driver of farmland bird declines. For the Eurasian Skylark (Alauda arvensis), 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 ...

雏鸟抚育阶段食物可获得性降低是农田鸟类种群衰退的核心驱动因子之一。对于欧亚云雀（Eurasian Skylark，学名Alauda arvensis）而言，其食物可获得性受多种因素影响，包括节肢动物丰度与多样性、植被可通行性以及距觅食位点的距离。在现代农田生态系统中，受植被通行性下降影响，该物种的食物可获得性预计会随繁殖季推进而逐渐降低。本研究以抚育雏鸟的欧亚云雀为对象，探究其觅食生境选择机制，重点关注生境利用与食物可获得性的季节动态变化。我们开展了三项核心研究内容：其一，围绕猎物生物量与多样性、植被盖度及距觅食位点的距离开展生境选择研究；其二，分析整体及季节尺度下的生境利用模式；其三，探究作为食物可获得性指示指标的觅食参数（如饲喂频次）的季节变化规律。2018至2019年，我们从中欧种群的51个鸟巢处，收集了抚育雏鸟的欧亚云雀配偶对的觅食生境与觅食参数数据。猎物生物量与多样性……