72 Microseasons of the Pacific Northwest

American black bears (Ursus americanus) enter torpor (a state of reduced metabolism distinct from true hibernation) in November or December at elevations where snow persists, and begin emerging from their dens in mid-March at lower elevations in the Pacific Northwest. In Oregon, most bears are out of dens by early March; in Washington and BC, the timing ranges from early March at low elevations to late April in subalpine zones. Females who have given birth to cubs (born in January during torpor) emerge with tiny, dark-furred cubs of the year — a particularly moving sight. Newly emerged bears are thin and their fur is often rubbed and patchy, but they are immediately active, moving downslope to south-facing slopes to find the first green growth. Early spring food sources include skunk cabbage shoots (already visible by this date), emerging grass blades in clearings, and winter-killed deer and elk carcasses. Bears can travel several miles per day in search of food after denning. The most reliable areas to observe early spring bears in the Pacific Northwest include the lower foothills of the North Cascades (particularly the Nooksack and Baker river drainages), the Quinault River valley in Olympic National Park, the forest edges of the Willamette Valley foothills, and agricultural interface areas in the Skagit and Stillaguamish valleys. Dawn and dusk are peak activity times. Black bears in the Olympics are notably large and have a higher proportion of cinnamon-phase individuals (brown-colored) than populations in most other PNW locations.