The Spotted Owl, Strix occidentalis, is a medium-sized owl with a heart-shaped face and no ear tufts. It has a rounded head and a short, square tail. The plumage is mottled with dark brown and white spots, giving it excellent camouflage against the bark of trees. This owl is a true denizen of the forest, relying on the complex structure of old-growth habitats.
Adult Spotted Owls typically measure around 43 cm in length, with a wingspan of 114 cm, and weigh approximately 600 grams. Their eggs are white and smooth, with a slightly grainy texture, measuring just over 50 mm in length. To distinguish them from the similar Barred Owl, look for the Spotted Owl's characteristic cross-shaped markings on the underparts, as opposed to the Barred Owl's alternating bars and streaks.
The Spotted Owl inhabits a variety of forest types, showing a preference for closed-canopy, uneven-aged, late-successional, and old-growth forests. The Mexican subspecies also utilizes chaparral and pinyon woodlands, including steep-walled canyons with sparse canopy cover.
Three subspecies of the Spotted Owl are distributed from British Columbia to Mexico. The Northern Spotted Owl ranges from southwestern British Columbia through parts of California, while the California Spotted Owl's range extends further south. The Mexican Spotted Owl is found in disjunct populations across the Southwestern US and into western Mexico.
Spotted Owls are nocturnal and exhibit a sit-and-wait hunting strategy, often swooping down on prey from a perch. They are monogamous and exhibit high site fidelity, with some pairs using the same nesting sites repeatedly. These owls do not breed every year, and juveniles typically disperse in late summer to fall.
The Spotted Owl's vocalizations include a series of hoots, often described as haunting and ethereal, which can carry through the dense forest they call home.
Breeding season spans from early spring to late summer or fall. Spotted Owls do not construct their own nests but use tree cavities or abandoned nests of other birds. Clutch size is usually two eggs, but can occasionally be as many as four.
The Barred Owl (Strix varia) is the most similar species, being larger and grayer with different breast patterning. Hybridization with Barred Owls has resulted in "sparred owls," which are interspecific hybrids.
The Spotted Owl's diet primarily consists of small mammals and birds. Prey items include flying squirrels, woodrats, deer mice, pocket gophers, voles, hares, rabbits, and various species of squirrels. They also consume bats, birds, amphibians, reptiles, and insects to a lesser extent.
The Spotted Owl is classified as Near Threatened, with a decreasing population trend. Habitat loss and competition with the Barred Owl are significant threats. The Northern and Mexican subspecies are listed as threatened under the Endangered Species Act, with the California Spotted Owl proposed for listing. Conservation efforts include habitat protection and management, as well as experimental removal of competing Barred Owls.