72 Microseasons of the Pacific Northwest

Great Horned Owls (Bubo virginianus) are the earliest-nesting large birds in the Pacific Northwest, often laying eggs in late January and beginning continuous incubation by the first days of February. The female incubates alone, sitting motionless on the nest through rain, wind, and frost for 30–37 days. On cold nights, only her ear tufts may be visible above the rim of the nest — typically a large stick platform abandoned by red-tailed hawks, great blue herons, or ravens, or occasionally a large tree cavity. The onset of incubation is preceded in December and January by the pairs' haunting territorial duets — the male's deep five-note hoot and the female's slightly higher response. These calls carry well on cold, still winter nights and are among the most evocative sounds of the PNW winter forest. Listen after dark in any forested park, riparian corridor, or rural area to locate active pairs. Ponderosa pine forests east of the Cascades, the forests of the South Puget Sound prairies, and Douglas-fir woodlands of the Willamette Valley and Puget lowlands all support dense owl populations. To find active nests, scan large stick nests for the pointed ear tufts and round facial disc of a sitting female. The Columbia National Wildlife Refuge near Othello, Washington, Ridgefield National Wildlife Refuge, and the forest edges of Mima Mounds Natural Area Preserve are reliable locations. Though the nest itself requires a careful search, the evocative hooting during this period — on January evenings before incubation becomes constant — is available to anyone willing to stand quietly outdoors after dark.