Courtesy Kenn Kaufman
Three distinct subspecies of Spotted Owl range from Canada's British Columbia to Mexico's Michoacan State. The "California" Spotted Owl (Strix occidentalis occidentalis
) is found in several mountain ranges throughout California. The "Northern" Spotted Owl (S. o. caurina
) replaces the California subspecies in the northern part of that state, and its range extends north to British Columbia. The "Mexican" Spotted Owl (S. o. lucida
) is found primarily in the Sierra Occidental in Mexico, north to New Mexico and Arizona, where it resides in several pockets of high-elevation forest.
Year round, Spotted Owls rely upon coniferous forests in the late stage (i.e., old growth, 200+ years old) for hunting, nesting in the unique, cool microclimate that these forests provide. With complex and varied structures, large stands of hemlock, Douglas fir, true firs, ponderosa pine, and mixed forests of pine and oak are used. They sometimes hunt on the forest edge or in small clearings, but these owls generally avoid crossing clear-cuts and openings. Roosts are in thicker stands of trees, often near water. Spotted Owls in California are found more often in deciduous hardwoods, especially oaks, from sea level to 3,200 feet.
The diet consists of medium-sized rodents, especially northern flying squirrels and dusky-footed woodrats, hunted between dusk and dawn. Other prey include brush rabbits, mice, pocket gophers, squirrels like Douglas and gray squirrels, voles, and many insects. Males and females probably hunt in slightly different habitats, in order to suit their size differences. Perching quietly, the owls ambush prey by diving on them with open talons. Climbing rodents can be plucked from branches. When prey are abundant, they may be stored temporally in a trees, rocks, or earthen hollows. Spotted Owls drink fresh water from streams and dripping rocks.
Spotted Owls form monogamous pair bonds that last many years, and they occupy the same home range together. In late winter or early spring, pairs begin to call and roost together. Like many other owls, Spotted Owls don't build a nest but instead use naturally occurring sites, 65 to 90 feet above ground, in tree holes, piles of leaves and sticks in a tree's crotch, large clumps of mistletoe, or the shelf of a cliff face. Old hawk or raven nests are also reused.
The female lays only one clutch of 2 - 3 whitish eggs and incubates them for about a month, while her mate feeds her. The downy white hatchlings are fairly helpless and blind. The female broods and feeds the young with items brought by the male. Owlets leave the nest in about 35 days and fly a few days later. Both parents tend the fledglings until September or October, when the full-grown young leave their parents' home range.
Spotted Owls are year-round residents in their range and are quite sedentary. The only significant movements occur when young disperse from their parents' territory or when the owls move during harsh winters to lower elevations, in order to find food. These temporary displacements cover 10 to 40 miles and represent drops in elevation between 1,600 and 4,800 feet.