Strix occidentalis caurina (Birds)

Species Description

The Northern Spotted Owl is one of three subspecies of spotted owl. Two of the subspecies are presently protected as “threatened” under the federal Endangered Species Act, and the third subspecies is the subject of a listing petition and subsequent litigation to gain protection for it as well.

Northern Spotted Owls Nuzzle at Muir Woods on August 10, 2008.
Comments by Ranger Mia Monroe.

This medium-sized owl has a round head and dark eyes, with a large heart-shaped facial disk. It has dense, brown plumage marked by large, white spots that give the species its moniker.

Found primarily in old-growth forests, Northern Spotted Owls are most often seen among large redwood, Douglas-fir, western red-cedar, and other coniferous forests with structural complexity so as to provide for all the bird’s habitat needs. Such diversity is rarely available in forests less than a few hundred years old.

Which is primarily why the Northern Spotted Owl is on the brink of extinction. The old-growth coniferous forests that the species depends upon for its survival are also prized timberland. After 200 years of commercial logging, more than 95% of California’s indigenous old-growth forests have been lost. As one might expect, preserving large-tracks of old-growth coniferous forests from logging is the most important conservation issue for the preservation of the Northern Spotted Owl.

In recent years a new threat has emerged: introgression and competition with the Barred Owl, an aggressive but closely related species that is native to Eastern North America. Barred Owls have been documented displacing Northern Spotted Owls in several locations, adding to conservationists’ concerns about the species.

In the GGNP, a good place to try and see this secretive species is in Muir Woods, where Northern Spotted Owls are known to nest, sometimes as close as ½ mile from each other. Marin County as a whole may have the densest population of nesting Northern Spotted Owls anywhere.

Conservation Action Item

Restore foraging habitat:
Volunteer at Muir Woods

Northern Spotted Owls require specific habitat conditions to flourish. Occasionally colonial, invasive weeds will alter natural habitats by choking out indigenous species and making it harder for Spotted Owls to find prey. Help restore owl foraging habitat by clearing invasive weeds in Muir Woods with National Park Service staff.

Big Year Competitors have reported 0 sightings and taken 4 actions to help this species recover so far this year.

Trips

• Owl Wars
  Saturday, 27 Feb 2010, 16:00 - 19:00 Pacific Time (US & Canada)
• Northern Spotted Owl Walk and Sounds of Muir Woods after Dark
  Sunday, 14 Feb 2010, 17:00 - 19:00 Pacific Time (US & Canada)
• Northern Spotted Owl Hunting Grounds Restoration
  Sunday, 11 Apr 2010, 09:30 - 14:30 Pacific Time (US & Canada)