Season and Age as Factors in Barred Owl (Strix varia) Admissions

Glori Berry

doi:10.53607/wrb.v30.58

Authors

Glori Berry BA Avian Haven

DOI:

https://doi.org/10.53607/wrb.v30.58

Keywords:

Aging, barred owl, dispersal, fluorescence, porphyrin

Abstract

Barred owl admittance data from Avian Haven, a wildlife rehabilitation facility in central Maine, were examined from April 2005 through March 2011. During this time, 231 barred owls were admitted to the facility, excluding nestlings. A significantly greater number of owls were admitted in the fall and winter months than in the spring and summer months; yearly variations in the fall and winter month admissions also were significant, while those for the spring and summer month admissions were not. Furthermore, a statistically significant proportion of 44 barred owls aged during the 2010/2011 fall/winter season were hatch–year birds, suggesting that yearly variations in barred owl admittance numbers are directly correlated with the number of dispersing hatch–year birds. Finally, in aging the barred owls for this study, a technique using an ultraviolet light source in the form of a black light to examine the fluorescence of porphyrin pigments in the feathers of owls was investigated. It was found to be reliable in differentiating hatch–year owls from adult (after–hatch–year) owls having undergone a partial molt, and has the potential for becoming the definitive method for aging barred owls in a rehabilitation setting.

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Author Biography

Glori Berry BA, Avian Haven

Glori Berry is a staff member at Avian Haven, a wildlife rehabilitation facility in Freedom, Maine. She is a former elementary school teacher and plans to attend graduate school in ornithology.

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