RE: age of Tyto alba pratincola, Barn Owls -
"A European barn owl banded in Helgoland, was recovered almost 15 years later. An American barn owl, banded in California as a nestling, lived ten years, 4 months; when found dead it had a full-grow jay clutched in its talons. In U.S. the oldest barn owl in the wild lived 11 years, 6 mo., 4 days; banded in Escondido, CA, caught near place of banding in October 1946 when still alive but died soon after; another individual reported from Holland lived 17 years,10 months."
- from John K./ Terres, The Audubon Soc.'s "Encyclopedia of North American Birds," p. 664