Documenting Northern Saw-Whet Owls Breeding in Mixed-Deciduous Forest

Abstract

Aegolius acadicus (Northern Saw-whet Owl) is an ecologically important, nocturnal, cryptic species that utilizes forests in Pennsylvania for stopover habitat, wintering , and breeding. The extent to which this species nests in the mixed-deciduous forests of northeastern Pennsylvania is uncertain. We used autonomous recording units (ARUs) and audio playbacks throughout Lackawanna State Park (LSP), PA, from mid-January through late March 2022 to assess potential breeding chronology and habitat-use patterns. Saw-whet Owls vocalized at 60% of ARU stations, and playback surveys produced an additional 2 acoustic detections. Incidental observations detected 2 fedglings in the park. Using ARU surveys, we documented their breeding chronology and found a positive association between vocalization rates and canopy cover. Our results suggest that Saw-whet Owls are nesting in the mixed-deciduous forest within LSP.