It lays its eggs in cavities in the broken tops of rotten trees or in large holes in trees. The owl is not afraid of people and will nest close to human settlements. The tolerance of the owl to man and urban disturbances is unusual. The owl lays from 3-12 eggs, depending upon whether food is scarce or abundant. The persistent presence of a single owl during late April is usually an indication that a nest is somewhere nearby.
Incubation begins when the first egg is laid.
It hatches about 28-35 days later, and the rest of the clutch hatches on subsequent days in the order laid. The young leave the nest when 20-22 days old, well before they can fly. Hawk owls are very aggressive at their nests and will attack any intruders. This is especially evident just after the young have left the nest. After the young are large enough to hunt for themselves, they disperse extensively within the boreal forest zone in response to food availability.