Great Horned Owls do not build their own nests, though they may provide some lining to an existing cavity or nest. Snags, cliffs and man-made structures provide nesting sites, but most commonly Great Horned Owls use the tree nests of other species such as hawks (especially Red-tailed) crows, ravens and squirrels. Most, but not all, nests are used for only one season. Pictured is a Great Blue Heron nest that has been usurped by a Great Horned Owl family – a feat achieved by the owls claiming the nest as early as February, prior to the return of herons.
After incubating her eggs for roughly a month, the female Great Horned Owl then broods her young for two to three weeks. The father’s role consists of bringing food to the female while she is incubating and brooding. She then tears the food up into bite-size pieces for the nestlings.
When the nestlings no longer need the heat their mother’s body provides, brooding ends but the mother stays with her nestlings until they fledge at about seven weeks of age. (Pictured: Great Horned Owl mother and two downy nestlings, roughly six weeks old. Thanks to Marc Beerman for photo op.)
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