wsc_owl

English

Western Screech-Owl
Otus kennicottii
Western Screech-Owl This information was scanned from The Birds of British Columbia (Campbell et al.), Volume II, pages 358-359. Volumes I, II and III of The Birds of British Columbia can be ordered electronically at: orders@ubcpress.ubc.ca from UBC Press in Vancouver, British Columbia.

Range
Resident from southeastern Alaska south along the coast to Baja California; in the interior from southern British Columbia south through Idaho, Utah, New Mexico, southeastern Colorado, and western Texas to southeastern Coahuila and Mexico City.

Status
Uncommon to fairly common resident on the south coast including Vancouver Island. Rare to uncommon resident on the northern mainland coast. Absent from the Queen Charlotte Islands. Rare to uncommon local resident in the central-southern interior; very rare in the west and east Kootenays. Breeds.

Status Change
No change.

Nonbreeding
The Western Screech-Owl occurs year round on Vancouver Island and on the adjacent mainland coast throughout the Fraser Lowlands to Hope. It probably also occurs as a resident along the northern mainland coast, west of the Coast Ranges, north to at least Terrace. In the interior, it is a local resident below 600 m elevation from Adams Lake and Shuswap Lake south through the Okanagan valley. Elsewhere, it is very rarely encountered.

The Western Screech-Owl is essentially non-migratory. On the coast, it is found in all woodland habitats, but it prefers mixed deciduous/coniferous forests, usually near a source of water. In the interior, most birds are found in deciduous woodlands along lakeshores and streams. It roosts in tree cavities, nest boxes, buildings, trees, vines, and crevices in cliffs. Hooting has been recorded every month on the coast but begins in earnest in February; in the interior, hooting begins in early March.

Breeding

Nests

Eggs

Young

The Western Screech-Owl breeds on southern and eastern Vancouver Island, the Gulf Islands, and the adjacent mainland coast, including the Fraser Lowlands to Chilliwack, north to Kitimat, including coastal islands (e.g. the Goose Group; Guiguet 1949). In the interior, it is known to breed only in the southern Okanagan valley.

This owl nests in open deciduous and coniferous woods and riparian habitats including rivers, creeks, marshes, bogs, lakes, and large ponds. In urban and residential areas it frequents orchards, parks, and gardens. Most nests were situated near water and none were found above 540 m elevation. Much of the information that follows is the result of nest box programs.

Nests:

Most nests (87%; n=62) were situated in wooden nest boxes (61%) and natural cavities (26%) of black cottonwood, red alder, Douglas-fir, western redcedar and western hemlock. All nest tree diameters were greater than 25 cm at breast height. Other nests (13%) were in cavities excavated by Pileated Woodpeckers and Northern Flickers.

Heights for 43 nests ranged from 1.2 to 12.2 m, with 65% recorded between 3.0 and 4.6 m. Depths of 3 tree cavities ranged from 30 to 36 cm; diameters of 2 entrance holes were 15 cm each. Nest materials were usually absent, but a few contained sparse collections of wood chips, feathers, moss, and mammal fur.

Eggs:

Dates for 49 clutches ranged from 17 March to 31 May, with 53% recorded between 9 and 21 April. Sizes for 51 clutches ranged from 1 to 5 eggs (1E-4, 2E-20, 3E-17, 4E-9, 5E-1) with 73% having 2 or 3 eggs. Incubation period is probably similar to that of O. asio which has variously been reported within range of 21 to 30 days (Bent 1938) but averages 26 days (Sherman 1911).

Young:

Dates for 53 broods ranged from 19 April to 21 August, with 51% recorded between 8 May and 3 June. Sizes for 46 broods ranged from 1 to 5 young (1Y-11, 2Y-16, 3Y-13, 4Y-5, 5Y 1), with 63% having 2 or 3 young. Fledging period, also for Oasio, ranges from 35 to 42 days (Bent 1938).

Remarks
There are several unconfirmed sightings and records of birds heard on the Queen Charlotte Islands. None are convincing, including a published occurrence by Patch (1922) who states ". . . believe I heard [at Tow Hill] . . . in woods bordering muskeg." Godfrey (1986) shows the range of the Western Screech-Owl extending north in the interior "rarely" to the Vanderhoof region (see Taverner 1919), however we are unaware of any interior records with convincing details north of Adams Lake.

The taxonomy of screech owls in North and Middle America remains confused. The American Ornithologists' Union (1957) lists 18 subspecies of screech-owls in North America. The Western Screech-Owl was formerly considered part of the Screech Owl (Otus asio) complex (American Ornithologists' Union 1957), but was separated from the eastern species on the basis of differences in vocalizations and behaviour as an "incipient species" (Marshall, J.T. 1967; American Ornithologists' Union 1983). Hekstra (1982) describes the subspecies of all North American Otus . The Western Screech-Owl is also known as Kennicotts' Screech-Owl.