Influence of human footprint and sensory disturbances on night-time space use of an owl

Abstract

Artificial sensory disturbances (sound and light) can extend far beyond the physical footprint of human development. Nocturnal predators such as owls may be influenced by artificial sound and light, as they depend on aural and visual cues when hunting. Owl nocturnal movements may also be altered by physical changes to the landscape, as these can affect prey availability. The burrowing owl population in Canada has declined by 90% and was classified as endangered in 1995. We tracked adult male burrowing owls Athene cunicularia with GPS dataloggers, and used resource selection models to examine their night-time movement patterns in relation to human infrastructure and associated artificial light and sound. The amount of sound and light from compressor stations, oil wells, traffic, towns and buildings was calculated for each owl and random location. We found that owl night-time space use was better predicted by distance to infrastructure on the landscape than by intensity of sensory disturbance. Burrowing owls did not show a pronounced avoidance of artificial sound. Infrastructure best predicts owl space use, perhaps because associated changes to vegetation alter prey abundance and availability. While human infrastructure most influenced owl nocturnal space use, the extent to which ecosystems are impacted by artificial sound and light is becoming clearer and needs to be considered when assessing the total effect of human development on species.