The Great Horned Owl (Bubo virginianus) is a powerful and highly adaptable bird of prey found across the Americas. As a primarily nocturnal predator, this raptor conducts the majority of its hunting activity between dusk and dawn. Its daytime resting period is known as “roosting.” To survive, the owl must select a location that provides security, concealment, and protection from harassment throughout the daylight hours.
Preferred Daytime Roosting Locations
Great Horned Owls choose their daytime resting spots based on the need for dense cover and protection from weather and predators. They frequently select large, mature trees, with conifers being a popular choice because their needles provide year-round screening. Deciduous trees also offer suitable concealment, particularly when leaves are present during warmer months.
The owl often positions itself on a thick branch close to the main trunk to maximize camouflage and stability. They also utilize natural structures such as rocky overhangs, cliff crevices, broken snags, or tree cavities. In human-modified landscapes, they may roost in abandoned barns, silos, or under bridges, but they generally prefer wooded areas. The location must shield the owl from daytime harassers like crows, which are known to mob resting owls.
Roosting Habits and Camouflage Strategies
Once a suitable roost is selected, the Great Horned Owl employs specific behaviors and physical adaptations to ensure it remains undetected. The owl’s mottled plumage, featuring shades of gray, brown, and tawny coloring, is effective at blending with tree bark and shadows. The ear tufts, which are feather structures, help break up the owl’s silhouette, making its outline less recognizable.
When resting, the owl maintains an upright posture, remaining almost completely motionless for hours. This stillness is a primary defense mechanism, relying on its natural camouflage. Favorite roost sites can sometimes be located by finding pellets—regurgitated balls of fur and bone—that collect on the ground below the perch. These feeding roosts are used consistently until the owl is forced to move due to disturbance or seasonal changes.
Seasonal Changes in Resting Sites
The Great Horned Owl’s choice of resting site is significantly influenced by the breeding cycle and prevailing weather conditions. They begin their nesting season early and do not construct their own nests. Instead, they take over existing structures, such as abandoned stick nests of Red-tailed Hawks, crows, or squirrels, or find suitable hollows in trees or on cliff ledges.
During incubation, the female rests on the nest, often hunkered down through harsh weather, while the male usually roosts nearby to guard the area and bring food. Once the young hatch, the female remains until the owlets are old enough to leave the platform and move onto adjacent branches, a stage known as “branching.” This requires temporary, secure resting perches near the main nest site.
In non-breeding periods, especially during winter, owls adjust their roosting locations to gain warmth. They seek out spots that receive more direct sunlight or offer better protection from wind and cold.