Master of Science degree with a major in Natural Resources, option Wildlife
Committee Chair Name
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
William "Tim" Bean
Second Committee Member Affiliation
Community Member or Outside Professional
Third Committee Member Name
Third Committee Member Affiliation
HSU Faculty or Staff
Wine producers in Napa Valley, California install barn owl (Tyto alba) nest boxes in vineyards with the goal of reducing rodent crop damage. Previous research has shown that the probability of attracting barn owls to nest boxes and encouraging them to hunt in vineyards is strongly influenced by the design of the nest box itself and the composition of the surrounding landscape. In 2017, wildfires in the Napa area burned nearly 60,000 ha, primarily affecting urban areas, which caused human devastation, and uncultivated habitats, which barn owls are known to select. Data collected before the fires on nest box occupancy and hunting habitat selection allowed for a comparative analysis of barn owl behavior before and after the fires. I analyzed four years of occupancy data on 273 nest boxes, finding that nest box occupancy was consistently associated with tall, wooden nest boxes that face away from the sun and have grassland and riparian land cover within the average hunting radius of the nest box. Additionally, wildfires increased nest box occupancy and modeling showed that the probability of a box becoming occupied after the fires was positively associated with the amount of fire edge within the average hunting radius of the nest box. I also analyzed GPS tracking data on 32 birds nesting in 24 individual nest boxes, with data collected before and after the fires. I found that barn owls are most likely to hunt in vineyard, grassland, riparian, and oak savannah land cover types and areas closest to the nest box, and these results were not affected by fire. Barn owls did show some hunting habitat selection for burned edges and low to intermediate severity burned areas, but their land cover type selection was resilient to landscape changes caused by wildfires. The combination of occupancy and hunting habitat selection analysis can be used to provide broad and durable guidance to wine producers who use barn owl nest boxes. With fires increasing in the western United States, the short-term resiliency of barn owls to the landscape changes caused by fires can have positive implications for their ability to provide pest control.
Huysman, Allison E., "Ecosystem services after a major ecological disturbance: did barn owl (Tyto alba) nest box occupancy and hunting habitat selection change in response to Napa Valley fires?" (2019). HSU theses and projects. 356.