Investigating biotic interactions as limiting factors of burrowing owl (Athene cunicularia) population recovery in British Columbia

Description

Burrowing owls (Athene cunicularia) were considered extirpated from British Columbia by 1980 and still require active management to sustain a breeding population. My research objective was to investigate if predator-prey interactions limit the survival and reproductive output of burrowing owls in British Columbia. Wildlife camera photographs and direct observations were used to assess survival, prey return rate and availability, and predator occurrence rate at six different conservation-breeding release sites across two regions and three reproductive-output levels. Ten out of the twelve nests studied successfully produced at least one juvenile owl that is presumed to have survived to the end of the 2023 breeding season. Results indicate that there may be regional differences in reproductive output and prey availability but not predator occurrence. Neither prey availability nor predator occurrence were significantly correlated with burrowing owl reproductive output, although some prey metrics were trending towards significance. However, competition over food resources with other species may be more detrimental to burrowing owls than previously thought, particularly over vertebrate prey items. Relationships between burrowing owls and the other species they interact with in British Columbia are complex; predator-prey dynamics alone do not account for the variability of burrowing owl success rates across the region. Active management such as supplemental feeding and anti-competitor deterrents at the entrances to burrows may be necessary to support this endangered species until it has reached more sustainable population numbers., burrowing owl, endangered species, wildlife management, predator-prey, trail cameras