Identifying Individual Great Gray Owls (Strix nebulosa) and Snowy Owls (Bubo scandiacus) Using Wing Feather Bar Patterns

Abstract

Abstract Bar patterns on flight feathers of Great Gray Owls (Strix nebulosa) and Snowy Owls (Bubo scandiacus) are variable, and can be used to recognize individual birds. Here I illustrate a method for taking photos of wings of captured owls and describe a way to arrange images of flying birds for comparison with photos of birds in flight or in the hand. I report four examples. First, two Great Gray Owls photographed in flight on different days at the same site were shown to be the same individual, but differed from a dead owl found at that location a month later. Second, I compared eight photographs of wintering Snowy Owls in flight in Saskatchewan and determined that they portrayed seven different owls. Third, I examined photos of breeding male first-year Great Gray Owls at neighboring nest sites and established that they were different birds. Finally, I compared photos of breeding female Great Gray Owls at the same nest site in 2011 and 2013, and determined that they showed two individuals. I suggest t...