Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance. We analyse timing of breeding and reproductive success in a migratory population of Eurasian kestrels (Falco tinnunculus) breeding in nest-boxes, over a full three-year abundance cycle of main prey (voles), and consider several components of individual quality, including body condition, blood parasite infection, and genetic diversity (n = 448 adults) that act on different time scales. Older individuals, and kestrel parents in higher body condition started egg-laying earlier than younger birds and those in lower body condition. Additionally, egg-laying was initiated earlier during the increase and decrease phases (2011 and 2012) than during the low phase of the vole cycle (2013). Nestling survival (ratio of eggs that fledged successfully) was higher in early nests and in heterogeneous landscapes (i.e., mosaic of different habitat types), which was evident during the increase and decrease phases of the vole cycle, but not during the low vole year. We found a strong positive effect of landscape heterogeneity on nestling survival, but only when voles were relatively abundant, whereas a difference in the timing of breeding related to territory landscape heterogeneity was not evident. Therefore, landscape heterogeneity appeared as the main driver of high reproductive performance under favourable food conditions. Our results show that landscape homogenization linked to agricultural intensification disrupts the expected positive effect of vole abundance on reproductive success of kestrels.

中文翻译：

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农业集约化导致的景观均质化破坏了鸟类捕食者的繁殖成功与主要猎物丰度之间的关系

选择高质量的栖息地和最佳的繁殖时间可以提高个体适应性，是塑造动物种群的强大进化因素。然而，很少有研究调查土地覆盖异质性、食物资源限制、个体质量和适应度参数的空间变化之间的相互作用。在这里，我们探讨了不同质量的个体如何应对猎物可用性（土地覆盖异质性）线索与实际波动的猎物丰度之间可能的不匹配。我们分析了在巢箱中繁殖的欧亚红隼（Falco tinnunculus）迁徙种群的繁殖时间和繁殖成功的时间，在主要猎物（田鼠）的完整三年丰度周期中，并考虑了个体质量的几个组成部分，包括身体状况，血液寄生虫感染，以及在不同时间尺度上起作用的遗传多样性（n = 448 名成年人）。年龄较大的个体和身体状况较高的红隼父母比年幼的鸟类和身体状况较低的鸟类更早开始产卵。此外，在增加和减少阶段（2011 年和 2012 年）比田鼠周期的低阶段（2013 年）更早地开始产卵。早期巢穴和异质景观（即不同栖息地类型的马赛克）中的雏鸟存活率（成功发育的卵的比率）较高，这在田鼠周期的增加和减少阶段很明显，但在田鼠低龄期则不然. 我们发现景观异质性对雏鸟生存有很强的积极影响，但只有当田鼠相对丰富时，而与地域景观异质性相关的育种时间差异并不明显。因此，景观异质性似乎是有利食物条件下高繁殖性能的主要驱动力。我们的研究结果表明，与农业集约化相关的景观均质化破坏了田鼠丰度对红隼繁殖成功的预期积极影响。