The northern spotted owl is one of three subspecies of spotted owl. A nonmigratory bird, this owl is found in Washington, Oregon, and Northern California in the United States and in parts of British Columbia in Canada. The scientific name for the northern spotted owl is Strix occidentalis caurina.
A medium-sized owl, the northern spotted is about 18 inches (45.7 cm) long and weighs 1–2 pounds (0.5–0.9 kg). Its wingspan is approximately 48 inches (122 cm). Gray-brown in color, these owls look like smaller versions of the barred owl and have light spots around their upper half. They do not have ear tufts, but unlike most owl species have darkly colored eyes.
Generally flying underneath the tree canopy and between trees, the northern spotted owl prefers old growth forests — forests left to grow without much human interference for at least 200 years — because of the variation between tree and branch heights and the gaps in the upper canopy. They are usually found near water sources and will not generally venture, even briefly, into non-forested areas. To combat temperature changes, this owl will fly higher or lower in the forest canopy.
Nocturnal hunters, northern spotted owls eat mostly small rodents, particularly flying squirrels. They wait for their prey on perches and then glide silently down to the ground or a branch, grabbing the prey in their talons. Though they are territorial, they may change their ranges slightly when environmental conditions impede their hunting.
Northern spotted owls mate in February or March and mate for life. Usually nesting in hollows in trees or other species' discarded nests, they also may use artificial nest boxes. A mated pair may have a territory as large as 2,000–5,000 acres (809–2,023 hectares).
The female lays two or three eggs and incubates them for about a month. Once hatched, the young are brooded by the mother for eight to ten days while the male hunts. The young fledge 34–36 days after hatching. Fledglings stay with their parents for two to three months while parents continue to feed them. The northern spotted owl lives about ten years in the wild but can live 15–20 years in captivity.
Spotted owls are considered an indicator species and are used by scientist to test the health of the ecosystems in which they reside. Unfortunately, the northern spotted owl is considered a threatened species. These birds have very specific habitat requirements and do not adapt well to changes in their environments. Deforestation is a main factor in their population declines. Barred owls, which frequently invade their territory, also result in declines in the northern spotted owl species.