School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA.
Department of Integrative Biology, University of Windsor, Windsor, ON, Canada.
Sci Rep. 2021 Dec 8;11(1):23619. doi: 10.1038/s41598-021-02821-y.
The expansion of urban landscapes has both negative and positive effects on wildlife. Understanding how different species respond to urbanization is key to assessing how urban landscapes influence regional wildlife behavior and ecosystem structure. Gulls are often described as strong urban adapters, but few studies have explored species-specific differences in habitat use. Here, we use GPS tracking in conjunction with stable isotope analysis (SIA) to quantify the habitat use and trophic ecology of great black-backed gulls (Larus marinus) and herring gulls (L. argentatus) in an urbanized area. Non-Metric Multidimensional Scaling (NMDS) of foraging locations revealed significant differences in the habitat use between species. Great black-backed gulls foraged primarily in marine habitats and herring gulls foraged primarily in specific urban habitats (e.g., landfills, dumpsters) and showed higher site fidelity in terms of the proportion of foraging sites revisited. Further, great black-backed gulls had significantly higher δN and δC than herring gulls, reflecting the use of marine, rather than urban, food sources. This study highlights the variability in urban habitat utilization among closely related species, assesses stable isotope signatures of urban diets in wild birds, and discusses ecological implications of the relative contribution of urban and marine foraging.
城市景观的扩张对野生动物既有正面影响，也有负面影响。了解不同物种对城市化的反应是评估城市景观如何影响区域野生动物行为和生态系统结构的关键。海鸥通常被描述为适应城市环境的能力很强，但很少有研究探索过物种特异性在栖息地利用方面的差异。在这里，我们使用 GPS 跟踪和稳定同位素分析（SIA）相结合的方法，来量化在一个城市化地区的大银鸥（Larus marinus）和黑背鸥（L. argentatus）的栖息地利用和营养生态。觅食地点的非度量多维尺度分析（NMDS）显示了物种之间栖息地利用的显著差异。大银鸥主要在海洋生境中觅食，而黑背鸥主要在特定的城市生境（如垃圾填埋场、垃圾桶）中觅食，并在返回觅食地点的比例方面表现出更高的地点忠诚度。此外，大银鸥的 δN 和 δC 值明显高于黑背鸥，反映了它们使用海洋而非城市的食物来源。这项研究强调了密切相关物种在城市栖息地利用方面的可变性，评估了野生鸟类城市饮食的稳定同位素特征，并讨论了城市和海洋觅食的相对贡献的生态意义。
