By Benjamin P. Burtt
BIRD COLUMN FOR Jan 7, 2007
The first bird to nest in the spring is the great horned owl. Its courtship begins any day now with lots of hooting and continues until the eggs are laid in mid-or late-February.
These owls do not make a nest of their own, but take over the old nest of a hawk, usually a red-tailed hawk or they may select a nest that was used by a crow or a squirrel. They seldom add any material. Once they have selected the site, they will spend some time around it as the moment for egg-laying approaches. The female will even sit in the nest before the eggs are laid.
These used nests are not always in good condition. They sometimes fall apart from wear and tear and the effects of storms. If there is no acceptable nest in the woods they have used in the past, they will have to move to another patch of woods to find another nest.
It takes about a month to hatch the eggs. Doing this in the winter the owls must contend with cold weather and snow. The female must stay with the eggs and the male brings food to her. When the eggs hatch, the male must find food for his whole family. The female stays with the young, keeps them warm and tears up prey brought in by the male. While she is incubating eggs or caring for small young she is sometimes completely covered by snow.
Most songbirds that nest in warm weather do not start incubation until all the eggs are laid. Thus all young hatch at the same time. For the horned owl, incubation must start with the first egg to keep it from chilling. So the eggs hatch at intervals of a day or two. At a given moment the nestlings will be of different sizes.
The great horned owl is a large bird. The distance from wing tip to wing tip is over 4 feet. The eyes face forward as do human eyes and the owl can judge the distance to its prey. Its eyes are large, about the size of human eyes and admit a lot of light that helps it to hunt when the illumination is poor. So important are its eyes that they occupy a space in its skull that is about twice that taken up by its brain!