Scientific Name: Asio flammeus
Taxonomy Group: Birds
Range: Yukon, Northwest Territories, Nunavut, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Prince Edward Island, Nova Scotia, Newfoundland and Labrador
Last COSEWIC Assessment: April 2008
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern
Image of Short-eared Owl
The Short-eared Owl has a large, round head, with small tufts of feathers that look like ears. This medium-sized owl measures approximately 34 to 42 cm in length. It has fairly long wings and a short tail. Adults have a brown back and creamy-buff chest with brown streaks. Sexes are similar in appearance, but females are slightly larger and tend to be darker. Juveniles resemble adults, but their plumage is somewhat more buff in colour. With its sober coloration, which acts as excellent camouflage, the Short-eared Owl is conspicuous only when it flies, often at dawn and dusk. It can easily be identified by its irregular flight, which resembles that of a foraging moth. It is characterized by deep wingbeats, occasional hovering, and a habit of skimming patches of grassland or marsh.
Distribution and Population
The Short-eared Owl is a bird that breeds on many continents and islands. In North America, it breeds sporadically in arctic areas, coastal marshes and interior grasslands, where voles and other small rodents proliferate. The Short-eared Owl breeds in all of Canada's provinces and territories, but is most frequently found in the Prairie provinces—Alberta, Saskatchewan and Manitoba—and along the Arctic coast. It generally heads southward in the winter and is found in open habitats along the extreme southern coast of British Columbia and in southern Ontario. It is also occasionally seen in coastal areas of Atlantic Canada or in the Prairie provinces, where the number of wintering individuals fluctuates significantly from one year to the next. It is believed that the owls that breed in the Prairie provinces travel south in winter and spend winter mainly in the Great Plains of the United States. The nomadic nature of the species makes it difficult to quantitatively assess population trends. In 2008, the Canadian population was estimated at 350 000 birds. Christmas Bird Count data suggest that the number of Short-eared Owls has declined at a rate of about 3% per year over the past 40 years, including a 23% decline over the past decade alone. Despite a recent increase in the Short-eared Owl population of the United States Great Plains grasslands, where a large number of these owls winter, there has been no notable increase in the breeding population in Canada.
The Short-eared Owl makes use of a wide variety of open habitats, including arctic tundra, grasslands, peat bogs, marshes, sand-sage concentrations and old pastures. It also occasionally breeds in agricultural fields. Preferred nesting sites are dense grasslands, as well as tundra with areas of small willows. While the Short-eared Owl has a marked preference for open spaces, the main factor influencing the choice of its local habitat is believed to be the abundance of food, in both summer and winter. Suitable breeding, migration and wintering habitat has declined significantly throughout the 20th century, resulting in a reduction in the number of owls.
The Short-eared Owl is a nomadic bird, and most individuals in the species wander widely both seasonally and annually. However, owls on islands appear to show higher fidelity to breeding sites. They group together in areas where prey populations are high. Unlike other owls, the individuals of this species build new nests instead of using abandoned ones. Only the female builds the nest, which typically consists of a single hole dug in the ground, lined with grass and a few feathers. Canadian populations generally raise a single clutch per year. If nests or eggs are destroyed, females will produce a second clutch. Between late April and early June, the female lays an average of four to seven eggs. Clutch size is directly related to prey abundance. The female incubates the eggs by herself for an average of 27 days, while the male guards the nest and brings the female food. Even before they can fly, nestling owls disperse short distances from the nest, hiding in nearby vegetation. Although its diet consists mainly of voles, the Short-eared Owl also feeds on a variety of small mammals, including shrews, pocket gophers, mice, kangaroo rats and lemmings. Many mammals, including foxes, skunks and feral cats and dogs, are predators of the eggs and nestlings. Avian predators include the Great Horned Owl, Snowy Owl, Red-tailed Hawk, Rough-legged Hawk, Northern Harrier, Northern Goshawk, Peregrine Falcon, Herring Gull and Common Raven. The species seems to be sensitive to human activity during the egg-laying and incubation stages, since females typically desert the nest if disturbed during this period.
Loss and alteration of habitat, especially coastal marshes and grasslands that were formerly heavily used by wintering owls, as well as grasslands of the Canadian Prairies and in southern Ontario, constitute the primary factors affecting Short-eared Owl populations. The disappearance of these habitats is mainly attributable to wetland drainage, urban development and increasing farm activity. Widespread and intensive livestock grazing occurs over much of the remaining pastures on the Canadian Prairies. This factor is a direct threat to Short-eared Owl habitat, as tall grasslands are typically preferred nesting sites for this species. In areas where the Short-eared Owl breeds amid crop fields, mowing and harvesting of hay and grains can be a significant source of egg and nestling mortality. Greater nest predation as a result of habitat fragmentation may also constitute a threat to the species. A decrease in the abundance of prey as a result of habitat changes, as well as the collision of adults with vehicles, utility lines and barbed-wire fences, may also contribute to population decline. Although elevated concentrations of pesticides, particularly organochlorines, have been detected in Short-eared Owl eggs, the effects of these contaminants are not yet well known.
Federal ProtectionMore information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
The Short-eared Owl is protected under a large number of provincial wildlife protection acts (e.g. Ontario's Fish and Wildlife Conservation Act and Quebec's Act Respecting the Conservation and Development of Wildlife). Legislation in most Canadian provinces prohibits the hunting, possession and selling of this species.
Provincial and Territorial Protection
Other Protection or Status
In Canada, the Short-eared Owl is not protected under the Migratory Birds Convention Act, 1994. It is, however, protected under the United States’ Migratory Bird Treaty Act when found on American soil. This Act prohibits the harming of birds, their nests or their eggs.
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
15 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Action Plans (6 record(s) found.)
- Management Plans (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
Recovery Document Posting Plans
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