Enticed by the migratory irruption of 2007, we established three banding stations in northeastern Alabama, USA, to determine the prevalence of Northern Saw-whet Owls (Aegolius acadicus) in the state and subsequently examine the broader extent of migration patterns and demographics at latitudes ≤35°N. We captured 202 Northern Saw-whet Owls between 2007 and 2016, with annual totals ranging from 3 in 2014 to 64 in 2012. The proportion of hatch-year owls captured was 38.1% overall, which was considerably lower than levels reported at more northern stations. Morphometric estimates and a sex-specific discriminant function analysis table indicated 63.9% of all Northern Saw-whet Owls captured were female and 11.9% were males, with the remaining 24.2% of undetermined sex. Peak migration occurred during mid-November. We locally recaptured 44 individuals and determined that recaptures were bimodally distributed, with most owls recaptured 1 wk after initial banding and a second peak 10–13 wk afterward. We estimated 50% of owls emigrated from stations within 3 wk of initial banding. We encountered seven owls initially banded at northern stations; one of these had flown 1518 km from Whitefish Point Bird Observatory, Michigan to Hollins, Alabama. Of these encounters, three were intra-seasonal and represented owls that had migrated at an average rate of 36.2 km/night. Four owls banded in Alabama were encountered during subsequent seasons in the northern United States. Although limited, these data suggest owls follow the Appalachian Mountains and western Great Lakes migration routes into Alabama. Our findings indicate Northern Saw-whet Owls regularly overwinter in northeastern Alabama, although abundances probably vary annually with migration dispersion cycles. We recommend additional Northern Saw-whet Owl banding stations be established across the southeastern United States to further study this secretive species within the southern periphery of its winter range.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 53 • No. 2