Reiley Bryan M, Benson Thomas J
Illinois Natural History Survey Prairie Research Institute University of Illinois Champaign Illinois.
Department of Natural Resources and Environmental Sciences University of Illinois Champaign Illinois.
Ecol Evol. 2019 Jun 11;9(12):7173-7183. doi: 10.1002/ece3.5288. eCollection 2019 Jun.
Habitat selection theory suggests that when choosing breeding sites, animals should choose the best available habitat; however, studies show that individuals fail to choose habitats that maximize their fitness especially in drastically altered landscapes. Many studies have focused on selection at single scales, often using a single measure of fitness. However, links between habitat selection and fitness may vary depending on the spatial scale and measure of fitness, especially in situations where agricultural land use has altered the surrounding landscape.We examined multiscale habitat selection and fitness measures of the Bell's Vireo () and Willow Flycatcher () using data collected in agriculturally fragmented landscapes.We found evidence for selection of nest sites with dense understory, larger patches, and increasing restored habitat cover and decreasing forest cover in the surrounding landscape.For both focal species, selection for dense understory significantly increased nest survival; however, there appeared to be no concurrent benefit for fledgling production. Selection for broader scale features positively influenced nest survival for the Willow Flycatcher with no concurrent benefit for fledgling production. The observed mismatches may be due to anthropogenic habitat fragmentation at broader scales or may represent reproductive trade-offs for a fitness benefit not measured in this study.Fine-scale habitat selection decisions by our focal species appear to match fitness outcomes, whereas habitat selection at broader scales only provided fitness benefits for the Willow Flycatcher. Though providing no fledgling production benefit, when combined with suitably dense nesting habitat, larger patches in landscapes with greater amounts of restored habitat cover for Bell's Vireo and lower amounts of forest cover for Willow Flycatcher will produce more fledglings per unit area than smaller patches in landscapes with less restored habitat and more forest cover, respectively, which could help inform conservation decisions for these at-risk species.
栖息地选择理论表明,动物在选择繁殖地点时应选择现有的最佳栖息地;然而,研究表明,个体未能选择能使其适应性最大化的栖息地,尤其是在急剧改变的景观中。许多研究聚焦于单一尺度的选择,通常使用单一的适应性衡量指标。然而,栖息地选择与适应性之间的联系可能因空间尺度和适应性衡量指标而异,尤其是在农业土地利用改变了周边景观的情况下。我们利用在农业碎片化景观中收集的数据,研究了贝尔氏绿鹃(Bell's Vireo)和柳莺(Willow Flycatcher)的多尺度栖息地选择和适应性衡量指标。我们发现有证据表明,它们会选择林下植被茂密、斑块较大、周边景观中恢复栖息地覆盖面积增加且森林覆盖面积减少的筑巢地点。对于这两种重点研究的物种而言,选择林下植被茂密的地方能显著提高巢穴存活率;然而,这似乎对雏鸟的繁殖没有同时产生益处。选择更广泛尺度的特征对柳莺的巢穴存活率有积极影响,但对雏鸟繁殖没有同时产生益处。观察到的这种不匹配可能是由于更广泛尺度上的人为栖息地碎片化造成的,或者可能代表了本研究未衡量的适应性益处的繁殖权衡。我们重点研究的物种在精细尺度上的栖息地选择决策似乎与适应性结果相匹配,而在更广泛尺度上的栖息地选择仅对柳莺有适应性益处。虽然对雏鸟繁殖没有益处,但当与适宜茂密的筑巢栖息地相结合时,对于贝尔氏绿鹃来说,在恢复栖息地覆盖面积较大且森林覆盖面积较小的景观中,较大的斑块每单位面积产生的雏鸟数量将比在恢复栖息地较少且森林覆盖面积较大的景观中的较小斑块更多;对于柳莺来说也是如此,这有助于为这些濒危物种的保护决策提供参考。