Boreal Owl

Occupying boreal forests around the top of the globe, the Boreal Owl also nests in sub-alpine forests of western U.S. mountain ranges. While females of most hawks and owls are larger than males, this difference is especially pronounced in Boreal Owls. Their anatomy contains a notable adaptation to their nocturnal habits, with the ear openings in their skulls being at very different heights to better determine the locations of sounds from prey.

Nomadic movements are common in Boreal Owls, at least in part due to food shortages that occur in their cold northern habitats. Availability of nest cavities can also be a problem in some areas. Most Boreal Owls live only 1.5 to 3.5 years.

\Male/breeding plumage:?T he Boreal Owl is a small owl with brown-streaked whitish underparts, brown upperparts heavily spotted with white, a pale bill, and black-framed white facial disks.

Sexes similar.

None.

Juveniles have solid brown chests and bellies.

Conifer forests.

Small mammals.

Forages at night by swooping down to capture prey.

Resident in Canada and Alaska, as well as parts of the western mountains in the U.S.

Intensive logging activity in the boreal forest is a threat to Boreal Owl populations.
Boreal Owl territories are only defended around the nest site, and not throughout the foraging area.

Short quick series of “who” notes are given during the breeding season.

The nest is in a tree cavity.

Eggs:  3-4.
Color:  White.

Incubation and fledging::
Young hatch at 26-32 days.
Young fledge (leave the nest) about 28-36 days after hatching, but remain with the adults for some time.

Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.

Bent Life History for the Boreal Owl – the common name and sub-species reflect the nomenclature in use at the time the description was written.

This is not the well-known Tengmalm’s owl of Europe, but another of those light-colored races of Siberian birds that has occurred as a straggler in North American territory. Dr. Barton W. Evermann (1913) reported, under the name of Cryptoglaux funerea funerea, the capture of a Tengmalm’s owl on St. Paul Island, in the Pribilof group, on January 26, 1911. It was caught alive in the village by a native and brought to Dr. Walter L. Hahn. “The stomach was empty save for a few hairs. This is the first record for America of this interesting little Owl.”

The specimen is now in the United States National Museum and has been referred to the race of Tengmalm’s owl ~which inhabits the Kernchatka and Kolyma districts in northeastern Siberia. According to Hartert’s (1920) description, this is a well-marked race, somewhat larger than the European race and lighter-colored, and slightly larger and much lighter-colored than our Richardson’s owl. The white markings on the upper parts predominate more than in other races, and the dark markings on the breast and flanks are narrower.

I can find nothing relating to the habits of this race, which probably do not differ essentially from those of the European or the American races.