A shy and elusive bird of prey, the boreal owl is more often heard than it is seen. Because of its diminutive size and reclusive nature, it is a treat for birders to spot, particularly during irruptive years when it may be spotted far south of its normal northern range.

Common Name:

Boreal Owl

Scientific Name:

Aegolius funereus

Appearance:

• Bill: Hooked, pale gray or pale yellow
• Size: 9-12 inches long with 23-inch wingspan, short tail, large head

• Colors: White, gray, brown, black, yellow
• Markings: Males and female birds are similar, though females are larger. Brilliant yellow eyes peer from whitish-gray facial discs bordered in dark brown or black. There is a white and brown wedge between the eyes, and white speckling at the four corners of the somewhat oval or rectangular face. The beak is surrounded by a brown moustache. Back and wings are dark brown with heavy white spotting, while the chest and abdomen are white with heavy brown streaks.

Foods:

Small mammals

Habitat and Migration:

Boreal owls are shy birds that prefer mature coniferous forests in the isolated boreal regions of Canada, Alaska and northern Eurasia, as well as similar climate zones at the highest elevations of mountain ranges in Idaho, Montana and Colorado. While these birds do not typically migrate, they may spread further south including into parts of Minnesota, Maine and the Northeast in severe winters or when food becomes scarce.

Vocalizations:

Knowing the boreal owl’s call will help birders locate these elusive birds.

The most common call is a high, fast “oo-oo-oo-oo-oo-oo” that lasts 2-3 seconds and grows stronger at the end.

Behavior:

Boreal owls are solitary birds that are primarily nocturnal, and in fact are very rarely seen during the day. They hunt from perches, and are known to cache food for later use. When retrieving the food, they will hold the frozen meat next to their body for it to thaw before eating.

Reproduction:

These are generally polygamous birds in regions where food is abundant, but if food supplies are weak they will remain monogamous. A mated pair will raise one brood of 2-5 eggs per year, with both male and female parents incubating the eggs for 28-37 days. The male will then hunt for the brood and the female will help tear the prey into suitable chunks while the young birds remain in the nest for 28-36 days.

Attracting Boreal Owls:

These small owls are not generally comfortable around humans, but they will use nest boxes on occasion. Birders living in suitable regions can encourage visits from boreal owls by leaving mature conifers standing and avoiding eradication of food sources such as rodents.

Similar Birds:

• Northern Saw-Whet Owl (Aegolius acadicus)
• Barred Owl (Strix varia)
• Northern Pygmy Owl (Glaucidium gnoma)

Photo – Boreal Owl © Nick Saunders