The effects of landscape composition and configuration on barn owl (Tyto alba) distribution, diet and productivity in the Fraser Valley, BC

Modern agricultural practices and urban development have altered agricultural landscapes resulting in the loss and degradation of habitat for wildlife. Barn owls are one of many farmland birds experiencing population declines across much of their range. I examined how changes to the agricultural landscape and current landscape composition and configuration have impacted barn owl site occupancy, diet and productivity in the Fraser Valley, B.C. Long-term and current site occupancy was influenced by increases in traffic exposure and the length of highways within their home range. I argue this results because highway traffic increases adult mortality. In contrast, productivity was influenced by the amount of impermeable surface, a pattern mediated by impacts on diet quality (%voles in diet). My work suggests that survival and productivity are influenced by two different aspects of the agricultural landscape, and points to the importance of considering both when managing barn owl habitat.