The provision of habitat for natural enemies of agricultural pests is common in integrated pest management approaches but has rarely been examined for vertebrate predators controlling vertebrate pests. To mitigate the economic and environmental costs of removing rodent pests in vineyards in Napa Valley, California, winegrape producers have installed nest boxes to attract American barn owls (Tyto furcata) to their properties. A rigorous estimate of how many rodents barn owls remove from the landscape is a necessary first step to understanding the overall impact of barn owls on rodent pest populations, and this study provides an estimate of rodent removal and prey composition by using remote nest box cameras. In addition, we tested hypotheses for how habitat may influence prey delivery rates and composition. Videography indicated that each barn owl chick received on average of 191 ± 10.01 prey items before fledging the nest box and that the amount of grassland habitat near the nest box and the proportion of deliveries of smaller prey were positive predictors of prey delivery rate. Prey composition was dominated by voles, gophers, and mice, and their relative proportions were associated with the composition of habitats near a nest box. Specifically, oak savannah was positively associated with the proportion of gophers and negatively associated with voles, and grassland was positively associated with voles. Further research on prey delivery should focus on the possible roles of rodent abundance, adult owl quality, and additional metrics of habitat structure.

在综合虫害管理方法中为农业虫害的天敌提供栖息地是很普遍的，但很少有人检查过控制脊椎动物虫害的脊椎动物掠食者。为了减轻加利福尼亚州纳帕谷葡萄园消除啮齿动物害虫的经济和环境成本，酿酒葡萄生产商已经安装了巢箱来吸引美国仓（Tyto furcata）的属性。严格估计从景观中去除多少只啮齿动物的啮齿动物是了解啮齿动物对啮齿类害虫种群总体影响的必要的第一步，并且本研究通过使用远程巢箱式摄像机来估计啮齿动物的去除和猎物组成。此外，我们测试了关于栖息地如何影响猎物输送速度和组成的假设。录像显示，每只仓雏鸡在出巢箱之前平均接受191±10.01个猎物，巢箱附近的草地栖息地数量和较小猎物的交付比例是猎物交付率的积极预测因子。猎物的组成主要是田鼠，地鼠和小鼠，它们的相对比例与巢箱附近的栖息地组成有关。具体来说，橡树大草原与地鼠的比例呈正相关，与田鼠呈负相关，草地与田鼠呈正相关。关于猎物传递的进一步研究应集中在啮齿动物的丰度，成年猫头鹰的质量以及栖息地结构的其他指标的可能作用上。