Bubo scandiacus
Largely unmistakable. Male almost pure white with black dots. Female and juveniles white with heavy black barring, and may seem grey at a distance. Juveniles more finely barred than adult females, giving them a greyer appearance, with white neck and face. Body barrel-shaped, head small and rounded. Wing-tips more pointed than in other owls. Flight action both buzzard and owl-like, with surprising agility. Note that several species of owls may seem completely white to the untrained eye when suddenly appearing in car headlights etc.
Song consists of single utterances or series of "aooo", recalling Great Black-backed Gull, and is far carrying. Male warning call a deep and harsh "groat grat grat", with accented endings of each syllable. Female warning call higher pitched. Also various other high pitched calls.
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology
