Short-eared Owl

Asio flammeus

Glen Tepke
  • STRIGIDAE
  • Owls
  • 2.4 million

The Short-eared Owl is a medium-sized hunter, inhabiting open fields, meadows, marshes, prairies, and tundra. With its widespread range and diurnal habits it is one of the most readily observed species of owl though serious declines across its range may place it in jeopardy.

Identification
Often first seen in flight, low to the ground over a grassland, marsh, or agricultural area, Short-eared Owls, though relatively small (15" in length), appear quite large with the broad wings typical of owls. The plumage is brown with buffy mottling and streaking on the breast. Short ear tufts are rarely visible. In flight, this bird shows an overall rich, buffy brown color with light and dark patches on the upper sides of its wings. Short-eared Owls have a buoyant flight style and are noticeably large-headed in flight. Eyes are yellow.

Distribution and Population Trends
One of the world's most widespread owls, the Short-eared Owl breeds across northern North America, northern Eurasia, southern and Andean South America, and the Greater Antilles. In North America it breeds from Alaska to Labrador south across approximately the upper third of the U.S., though its is now a rare breeder in the northeast U.S. Wintering birds migrate as far south as Florida, central Mexico, and Baja California. Short-eared Owls are regular breeders at the North Mojave Dry Lakes California IBA. Point Peninsula, an IBA in New York, supports up to 30 wintering Short-eared Owls, while the Boundary Bay - Roberts Bank - Sturgeon Bank (Fraser River Estuary) IBA in British Columbia regularly supports as many as 75 wintering Short-eared Owls.

This is a species in serious decline over much of its range. Breeding Bird Survey data show a statistically significant 3.5% per year decline from 1966-2001 across the overall range and an even steeper decline of 11.4% per year in Canada. In the northeastern U.S. the species was listed as threatened in 7 states as of 1993.

Ecology
A partially diurnal owl, this bird can be seen hunting over fields, marshes, meadows, prairies, and tundra in the late afternoon and early evening hours. In winter, it sometimes also forages over fallow agricultural fields. Its primary food is small rodents and in areas where there is an abundance of its food birds may concentrate even roosting together. Breeding commences with dramatic spiraling courtship flights from the male. Nests are constructed by the female and merely involve scraping a bowl in the ground and lining it with grasses and feathers. Clutch size is highly variable, ranging from 3-11 depending on food availability. Adults can be quite aggressive to intruders near the nest, sometimes even diving at humans.

Threats
Like many species dependent on grasslands or other open lands, the primary threat to the Short-eared Owl is the destruction and degradation of open habitat. From agriculture to human development to successional reforestation, this species is losing open fields, meadows, and marshes where it prefers to nest and spend winters. The species may also be affected by pesticides accumulated through its prey, especially during winter when Short-eared Owls often occur in agricultural areas but this has not been studied.

Conservation
Conservation efforts undertaken are usually similar to those of other grassland breeding birds. Management protocols such as prescribed burns, periodic mowing, and efforts to maintain waterfowl breeding sites all lend aid to preserving habitat necessary for Short-eared Owls. However, because these birds are partially nomadic in winter and could appear anywhere in suitable habitat, habitat should be preserved in both known and potential breeding and wintering sites.

Efforts to protect grassland habitat are underway through a number of initiatives including several Audubon state offices. In Illinois, Chicago Wilderness Audubon is partnering with the Forest Preserve District of Cook County to restore a 600-acre grassland. Audubon Connecticut has convened a Grassland Working Group to identify the current status of grassland birds in the state and to examine ways to protect and enhance grasslands. Audubon New York was successful in its bid to turn the former 600-acre Galeville Airport Important Bird Area (a wintering site for Short-eared Owls) into the Shawangunk Grasslands National Wildlife Refuge. Massachusetts Audubon initiated a Grassland Conservation program in 1993 that has produced many excellent outreach materials for public land managers and private land owners interested in managing their lands for grassland birds and much of this information is available via their website.

What Can You Do?
Audubon's Important Bird Areas program is a vital tool for the conservation of Short-eared Owls as well as other species. To learn more about the Important Bird Area programs and how you can help, visit: http://www.audubon.org/bird/iba/.

Support local land trusts, government agencies, and other organizations working to preserve Short-eared Owl habitat in your area. Contact your state Important Bird Areas coordinator (http://www.audubon.org/bird/iba/state_coords.html) to find out if there are sites in your area important for Short-eared Owls that need increased protection.

Information on where Short-eared Owls occur and in what numbers is vital to conserving the species. Help in monitoring this and other species by reporting your sightings to eBird. A project of Audubon and the Cornell Lab of Ornithology, eBird is the world's first comprehensive on-line bird monitoring program: http://www.audubon.org/bird/ebird/index.html.

U.S. National Wildlife Refuges provide essential habitat for Short-eared Owls, and a great number of other species throughout the U.S. and its territories. Unfortunately, the refuge system is often under-funded during the U.S. government's budgeting process. To learn more about how you can help gain much needed funding for U.S. National Wildlife Refuges, visit: http://www.audubon.org/campaign/refuge_report/

Volunteers are crucial to the success of programs that monitor the long-term status of wintering populations of Short-eared Owls and other bird species. Audubon's Christmas Bird Count (CBC) is one of the longest-running citizen-science monitoring programs in the world and has helped to follow changes in the numbers and distribution of Short-eared Owl. To learn more about the CBC and how you can participate, visit: http://www.audubon.org/bird/cbc.

The Canadian Nature Federation and Bird Studies Canada, Audubon's BirdLife partners in Canada, jointly administer an Important Bird Areas program that is working to identify and protect habitat for Short-eared Owls and many other species. To learn more visit: http://www.ibacanada.com/.

CIPAMEX, Audubon's BirdLife International partner in Mexico, has an Important Bird Areas program that is working to protect wintering habitat for Short-eared Owls and many other species. To learn more about Mexico's Important Bird Areas program and how you can help visit: http://132.248.79.80/wwwcampus/cipamex/

The Raptor Research Foundation is a non-profit scientific society committed to understanding raptors. The researchers, government employees, and others interested in raptors that are members of this organization inform the public about the ecological role of raptors and promote their conservation. To find out more and how you can become a member, visit: biology.boisestate.edu/raptor/rrfc.htm

References
Holt, D. W. and Leasure, S. M. 1993. Short-eared Owl (Asio flammeus). In The Birds of North America, No. 62 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D. C.

Kaufman, K. Lives of North American Birds. New York: Houghton Mifflin Company, 1996.

Konig, C., F. Weick, and J. Becking. 1999. Owls A Guide to the Owls of the World. Yale University Press, New Haven.

Sibley, David A. The Sibley Guide to Birds. New York: Alfred A. Knopf, 2000.