A History of Oregon Ornithology: From Territorial Days to the Rise of Birding Edited by…
We have been hearing owls in the evening at our property in the forested area southwest of Eugene. In all of the 22 years we have lived here, Great Horned Owls have nested nearby. Before sundown and into the evening, deep hoots echo through Fox Hollow; the deeper voice is the male and the higher pitched hoots are the larger female. Breeding season has already begun for this species, even though the landscape is wet and the temperatures wintery. Those deep hoots are communicating territory claims as well as courtship and pair bonding—annual rituals for the pair that mates for life.
Great Horned Owls start nesting in January, raising their families in the depths of winter. Like other owls, they do not build their own nests, but take over the abandoned homes of other species, including squirrels, ravens, herons, and Red-tailed Hawks. The female incubates the eggs while her mate brings her food. Within a month, up to five eggs will hatch. The owlets are closely guarded by their parents. Six weeks after hatching, the owlets begin to walk around the nest tree branches. In another three weeks, the young owls will already have learned to fly. The parents continue to feed and care for their offspring for several months, often as late as October. It is wise to stay away from young owls and their nests because Great Horned Owls are protective if they feel their family is threatened.
Owls are nocturnal predators, and Great Horned Owls feed on practically any living thing—fish, frogs, scorpions, squirrels, skunks, crows, ducks, and bats. They will even take down large raptors, including hawks, ospreys, and other owls. According to the Cornell Lab of Ornithology website, the birds “have the most diverse diet of all North American raptors.”
There aren’t many birds or mammals that prey on the Great Horned Owl, but it does have its threats—humans among them. Loss of habitat through urban sprawl decreases the owl’s nesting and hunting territories. The use of insecticides and pesticides targeting insects and rodents can either harm the owls directly or harm owls by reducing their natural food supply.
Each year we look forward to the cool winter evenings’ hooting serenade. If you are outdoors in the evening, listen for these magical sounds of nighttime winter wooing in the trees!
For more information, see the Cornell Lab of Ornithology website: www.allaboutbirds.org/guide/great_horned_owl/lifehistory/ac.