Can Barn Owls Help Control Rodents in Winegrape Vineyard Landscapes? A Review of Key Questions and Suggested Next Steps

Abstract

Many winegrape farmers have installed nest boxes to attract barn owls to manage rodent pests, but this prospect has not been rigorously examined. We provide a brief history and context of the use of, and research on, barn owl nest boxes in California vineyards, and we suggest six key research questions necessary to better evaluate the capacity for barn owls to help control rodent pests: 1) How and where should boxes be placed to enhance barn owl occupancy? 2) How much are owls hunting in vineyards versus surrounding habitat? 3) How many rodents do they remove from vineyards? 4) Do they remove enough to meaningfully reduce rodent numbers and decrease crop damage? 5) What can farmers do to maximize hunting on their vineyards? and 6) What factors influence farmers’ decisions to use or not use nest boxes? Some work has recently been aimed at questions 1-3, but additional work is needed to confirm and generalize those results, and questions 4-6 remain, to date, unanswered. We suggest a research agenda to help address those unmet needs and advance our understanding of the potential for and application of barn owl nest boxes for pest management in winegrape vineyards.