The boreal owl or Tengmalm's owl (Aegolius funereus) is a small owl in the 'true owl' family Strigidae. It is known as the boreal owl in North America and as Tengmalm's owl in Europe after Swedish naturalist Peter Gustaf Tengmalm or, more rarely, Richardson's owl after Sir John Richardson. Due to the boreal owl's shyness and evasive reaction to human activities, nocturnal habits and preferred inaccessible taiga forest habitat, it is rarely seen by humans. The boreal owl is 22–27 cm (8.7–10.6 in) in length and has a wingspan of 50–62 cm (20–24 in). A female is heavier than a male bird and weighs 131–179 g (4.6–6.3 oz) compared with an average of 107 g (3.8 oz) for a male bird. The plumage is brown above, with white flecking on the shoulders and whitish underparts with rust-colored streaks. The head is large with yellow eyes and a dull white facial disc that is sometimes described as giving the owl a 'surprised' expression. The beak is a light yellow, rather than dark like its relative the northern saw-whet owl. The sexes are similar in appearance. The plumage of young birds is chocolate brown. The boreal owl's flight is relatively noiseless and straight. (Source: Wikipedia.org, CC BY-SA)