Common name: Northern spotted owl

Scientific Name: Strix occidentalis caurina

"Strix" = to screech; referring to its call (Greek)

"occidentalis"= western (Latin)

Description: The spotted owl is about the size of a crow and has a large round head with black eyes and a spotted head, neck, and underside. Its chest is barred with brown. Its ears are not visible. Its main call is a series of three or four hesitant, dog-like barks and cries (Scott 1987).

Geographical range: The Northern spotted owl is a resident from Northern California, to western Oregon and Washington, and southwestern British Columbia, Canada.

Habitat: The Northern spotted owl inhabits dense, humid coniferous forests with canopy closures of at least 80% or on mixed woodlands and deeply shaded canyons in coastal and mountain ranges on the west coast. It requires a large forested environment with a multi-layered canopy, large crowned old-growth trees, and snags. Its habitat is usually found at less than 4,200 feet elevation (DeGraaf et al. 1991).

Reproduction: This owl requires 2,700-4,500 acres of dense old-growth forest or deep, narrow, heavily wooded canyons per breeding pair (Kirk and Franklin 1992). It generally nests in cool, shaded areas with a well developed understory. It prefers to nest on the broken top of a snag or on platforms created by Dwarf Mistletoe or hollowed out logs or snags. It rarely builds its own nest in a branch node (DeGraaf et al. 1991). Its breeding season is from early March to mid-April. These owls start breeding when they are 2-3 years old and do not reproduce every year. They have 2-4 eggs per clutch. The chicks hatch after 28-30 days of incubation. The female sits on the nest and incubates the egg while the male brings the female food. Only 11% of the offspring survive from birth to breeding age and on average each breeding pair has .49 offspring throughout their lifetime (Kirk and Franklin 1992).

Input requirements (food supply): Preys on a wide variety of animals, but mostly eats small mammals like mice, squirrels, or voles (DeGraaf et al. 1991). It relies heavily on eating Northern Flying squirrels.

Role in the ecosystem: Maintains small mammal populations.

Use as a Human Resource: The northern spotted owl is considered an "Indicator species". When its populations cease to reproduce or are declining in numbers, it is an indication that the forest ecosystem is suffering from fragmentation.

Notes: This owl is strictly nocturnal and lives up to 15 years (Kirk and Franklin 1992).

Its close relative and subspecies, the Southern spotted owl (Strix occidentalis) ranges throughout the mountains of southern Utah, central Colorado, Arizona, New Mexico, western Texas, south into Mexico (DeGraaf et al. 1991).

This Northern spotted owl is considered rare as its populations have severely declined over the last century due to the clearcutting of old-growth coniferous forests. As of 1992, approximately 500 pairs existed in Washington and fewer than 100 in Canada (Environment Canada, www.speciesatrisk.gc.ca/Species/English/SearchDetail.cfm/). In the U.S., the Northern spotted owl is federally listed as a threatened species. Both the US and Canada have developed long-term studies and forest management to eliminate the extinction of this species, however, its populations are still in decline.

The spotted owl is also threatened by another species in its same genus, Strix varia, the Barred Owl. The Barred owl looks incredibly similar to the spotted owl, except that it is a slight bit bigger in size. The Barred owl feeds on the same food as the spotted owl and can live on the edges of clearcuts and in disturbed forests, therefore directly competing with the availability of resources. The Barred owl is also more aggressive than the Northern spotted owl and literally chases the spotted owl out of its habitat (Kirk and Franklin 1992).