This taxon is Not Recognised as a species by BirdLife International.
Strix aluco and S. nivicolum (del Hoyo and Collar 2014) were previously lumped as S. aluco following Sibley and Monroe (1990, 1993).
BirdLife International (2016) Species factsheet: Strix aluco. Downloaded from http://www.birdlife.org on 04/12/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/12/2016.