Data from: Conventional oil and natural gas infrastructure increase brown-headed cowbird (Molothrus ater) relative abundance and parasitism in mixed-grass prarie

The rapid expansion of oil and natural gas development across the Northern Great Plains has contributed to habitat fragmentation, which may facilitate brood parasitism of ground-nesting grassland songbird nests by brown-headed cowbirds (Molothrus ater), an obligate brood parasite, through the introduction of perches and habitat edges. We tested this hypothesis by measuring brown-headed cowbird relative abundance and brood parasitism rates of Savannah sparrow (Passerculus sandwichensis) nests in relation to the presence of infrastructure features and proximity to potential perches and edge habitat. The presence of oil and natural gas infrastructure increased brown-headed cowbird relative abundance by a magnitude of four times, which resulted in four times greater brood parasitism rates at infrastructure sites. While the presence of infrastructure and proximity to roads were influential in predicting brood parasitism rates, proximity of perch sites was not. This suggests that brood parasitism associated with oil and natural gas infrastructure may result in additional pressures that reduce productivity of this declining grassland songbird.

北美大平原北部的石油与天然气开发规模快速扩张，引发了栖息地破碎化。该过程可通过增设栖木与生境边缘，助力专性巢寄生鸟类褐头牛鹂（Molothrus ater）对地面筑巢的草原鸣禽巢穴实施巢寄生。本研究通过测量褐头牛鹂相对丰度、萨凡纳雀（Passerculus sandwichensis）巢穴的巢寄生率，并结合基础设施特征的存在情况、与潜在栖木及边缘生境的距离，验证了上述假说。研究结果显示，石油与天然气基础设施的存在使褐头牛鹂相对丰度提升了四倍，进而使基础设施周边样点的巢寄生率也升高了四倍。尽管基础设施的存在以及与道路的距离对巢寄生率的预测具有显著影响，但与栖木位点的距离却未表现出关联。这表明，与石油和天然气基础设施相关的巢寄生现象，可能会带来额外的生存压力，进一步降低这种处于种群衰退中的草原鸣禽的繁殖成功率。