The spotted owl (Strix occidentalis) is a species of true owl. It is a resident species of old-growth forests in western North America, where it nests in tree hollows, old bird of prey nests, or rock crevices. Nests can be between high and usually contain two eggs (though some contain as many as four). It is a nocturnal owl which feeds on small mammals and birds. Three subspecies are recognized, ranging in distribution from British Columbia to Mexico. The spotted owl is under pressure from habitat destruction throughout its range, and is currently classified as a near-threatened species.

Distribution

The northern spotted owl has a nearly contiguous range from southwestern British Columbia south through western Washington and Oregon to Marin County, California. The California spotted owl's range overlaps this range in the southern Cascade Range, and extends south through the western Sierra Nevada to Tulare County, with discrete populations in mountainous areas of coastal and southern California from Monterey County to northern Baja California. The Mexican spotted owl occurs in disjunct populations in mountain ranges and canyons of the Southwestern US (including Utah, Colorado, Arizona, New Mexico, and extreme western Texas), as well as in western Mexico (Sonora, Chihuahua, Nuevo León, and eastern Coahuila) through the Sierra Madre Occidental and the Sierra Madre Oriental. and more high-severity fire in a territory increases reproduction.

thumb|left|Mexican spotted owl, [[Fort Huachuca, Arizona]]

Large trees seem to constitute preferred nesting and roosting habitat for all three subspecies, Spotted owls most often choose the same type of cover selected for nesting sites for daytime roosting.

Spotted owls are nocturnal, sit-and-wait predators. They often hunt from a perch and swoop or pounce on prey, or may take arboreal prey from tree boles and limbs. They do occasionally hunt during the day. Although diet varies with location, the majority consists of a few mammalian species. Species taken most often are northern flying squirrels (which may comprise more than 30% of total prey) and woodrats (the most common prey overall), including dusky-footed (Neotoma fuscipes), bushy-tailed, (N. cinerea), and Mexican woodrats (N. mexicana). In some portions of its range, much of the spotted owl's diet is composed of several other mammals such as deer mice (Peromyscus maniculatus), pocket gophers (Thomomys spp.), voles (Microtus, Clethrionomys, and Phenocomys spp.), snowshoe hares (Lepus americanus), rabbits, and several species of squirrels. Bats and non-mammalian prey species are taken to a lesser extent, including birds (smaller owls, jays, woodpeckers, and passerines, including various songbirds), amphibians, reptiles, and insects. All studies assessing the species' population trend have found populations to be in decline. Habitat loss due to timber harvesting is generally recognized as the main threat. Forest and spotted owl management documents often state that severe wildfire is a cause of recent declines in populations of spotted owls, and that mixed-severity fires (5–70% of burned area in high-severity patches, with >75% mortality of dominant vegetation) pose a primary threat to spotted owl population viability, but a systematic review and meta-analysis found fires created more benefits than costs for spotted owls. The northern spotted owl was one of a few cases where the "God committee", a provision of the Endangered Species Act, has been invoked to decide whether or not to open up more federal forest for commercial logging.

References

  • Read Congressional Research Service (CRS) Reports regarding the spotted owl
  • CBS News: Blasting Some Owls To Save Others? Government Proposes Selectively Killing Cousins Of Threatened Spotted Owls To Protect The Species
  • B.C.'s spotted owl near extinction: Science advisory team recommends capturing and breeding remaining owls in British Columbia
  • Spotted Owl videos on the Internet Bird Collection
  • Spotted Owl photo gallery on VIREO
  • Spotted owl Species Account – Cornell Lab of Ornithology