Lunar influence on the fall migration of Northern Saw-whet Owls

Abstract

Seasonal migration is an important component in the life cycle of Northern Saw-whet Owls (Aegolius acadicus). We evaluated the influence of the four lunar events (new moon, first quarter moon, full moon, and last quarter moon) on nocturnal activity of Northern Saw-whet Owls based on captures during fall migration, 2000-2008. We found differences between the lunar events with decreased capture rates during the full moon and the new moon. These results suggest lunar phase influences migratory movements and behaviors in this species. This may be attributed to predator avoidance during periods of relative brightness or darkness at night. © 2011 by the Wilson Ornithological Society.