Boreal Owl

The Boreal Owl, also known as Tengmalm's Owl in Europe or, more rarely, Richardson's Owl, is a diminutive member of the true owl family, Strigidae. This elusive bird is characterized by its brown plumage with white flecking on the shoulders and a facial disc that imparts a somewhat surprised expression, thanks to its large head, yellow eyes, and light yellow beak. The underparts are whitish with rust-colored streaks. With a length of 22–27 cm and a wingspan of 50–62 cm, the female typically outweighs the male, tipping the scales at 131–179 g compared to the male's average of 107 g.

Identification Tips

To identify the Boreal Owl, look for its brown upperparts and whitish underparts with rust-colored streaks. The large head with yellow eyes and a white facial disc are distinctive, as is the light yellow beak. The flight of the Boreal Owl is relatively noiseless and straight, and juveniles can be recognized by their chocolate brown plumage.

Habitat

The Boreal Owl favors dense coniferous forests, a habitat that provides both the seclusion and the hunting grounds it requires. These forests span across northern North America and the Palearctic, as well as mountainous regions like the Alps and the Rockies.

Distribution

This species is predominantly non-migratory, with its breeding range extending across the northern latitudes of North America and Eurasia. However, during certain autumns, some individuals may venture further south, though rarely far from their typical breeding areas.

Behaviour

The Boreal Owl is largely nocturnal, especially in the northernmost parts of its range where summer nights are brief, necessitating daylight hunting. It is known for its shyness and evasive reaction to human activities.

Song & Calls

The call of the Boreal Owl has been likened to the "winnowing" sound of the North American Wilson's snipe, a distinctive auditory marker for those in the field.

Breeding

Boreal Owls commence breeding at the age of one. They nest in tree cavities, often those created by woodpeckers, and readily adopt nest boxes. Clutches typically consist of 3–7 eggs, which are incubated by the female starting with the second egg. The eggs hatch asynchronously after 25–32 days, and the young fledge at approximately 28–33 days of age.

Diet and Feeding

The diet of the Boreal Owl is primarily composed of voles and other small mammals, such as mice and squirrels, but it also includes birds, small amphibians, insects like beetles, and other invertebrates. It hunts mostly at night, though in high latitudes, it may be active during daylight in summer.

Conservation status

The Boreal Owl is currently listed as Least Concern by the IUCN, indicating that, at present, there are no immediate threats to its population levels that would warrant a higher degree of concern.