Distinguishing Features:
Medium-sized (crow-sized) buffy
white owl. The upper parts are broadly streaked with brown and the
abdomen narrowly and more sharply streaked with brown. Ear tufts
very short, scarcely discernable. Flight feathers and tail barred
with brown. Yellow eyes. Total length 33-43 cm. (Godfrey, 1986).
Distribution
Columbia Basin: In appropriate habitat
throughout the Columbia Basin. More common in the south.
British Columbia: Winter populations
are concentrated in the lower Fraser River valley, with smaller
numbers on southeast Vancouver Island and the southern interior
valleys. Breeding is more dispersed, occurring locally in the lower
Fraser River valley as far east as Ft. Langley, and in the south
and central interior valleys from Creston and the Okanagan Valley
as far north as Prince George, possibly into the Peace River (Cannings
et al. In prep.).
Global: Breeds in Iceland and across
n. Eurasia, south to s. Europe, Afghanistan and Sakhalin; n. North
America south to California, Colorado, Missouri, Ohio and Virginia;
Patagonia and the mountains of n. South America; Winters in North
America throughout most of breeding range; from s. British Columbia,
Montana, Ontario and Massachusetts south to c. Mexico. (Cannings
et al. In prep.).
Habitat
Open Grassland, grassy or bushy
meadows, marshes and bogs. Short-eared Owls nest in open treeless
areas such as grasslands, rangelands, dry marshes, farmlands, low-arctic
tundra, brushy fields and forest clearings. Winter habitats of the
Short-eared Owl are also in open country, including marshes, swamps,
lakeshores, spits, sedge-cranberry fields, sedge-hardhack fields,
and grasslands. In British Columbia, coastal grasslands and old-field
habitats are the most important (Cannings et al. In prep.).
Threats
Directly threatened by rapid urbanization,
industrialization and intensive agriculture in the limited breeding
and wintering habitats. Human disturbance of nesting and wintering
areas is also a significant problem. Habitat loss and human disturbance
have also caused local declines. Intensive grazing around wetlands
is a potential of threat at breeding sites. Fragmentation of habitats
can also accentuate the magnitude of population fluctuations of
their prey (Cannings et al. In prep.).
Biology
Communal roosts of up to 110 birds have been documented
in tall-grass fields and on the lee side of dykes in the Fraser
River delta. Meadow voles (Microtus ssp.) dominate the diet,
but other mammals (e.g. shrews, moles, rabbits, pocket gophers)
and birds are also taken (Cannings et al. In prep.). Migratory Short-eared
Owls arrive on the nesting grounds in British Columbia from late
March through mid-April. Although clutches have been observed from
the end of March to early July, most nesting occurs between late
April and early May. Clutch size ranges from 1 to 13, with 6 - 8
eggs being most common. The incubation period lasts approximately
24 days and brood size ranges from 1 to 8 young (5 or 6 being most
common). The young leave the nest at 12 - 16 days old and begin
to fly at 22 - 28 days old. Fall migration occurs from late October
through November (Cannings et al. In prep.).
