Great horned owls are the heaviest owls in the greater Yellowstone ecosystem, and the second-largest in the Americas, after the snowy owl. They typically have wingspans of three to five feet and can weigh as much as 3-1/2 pounds. The “horns” on their heads are actually feathers, and they are feathered all the way down to their feet.
Their coloration is browns and grays, which provide for excellent camouflage. Their eyes are very large for their size, proportionately among the largest of all land vertebrates.
Great Horned Owls in this ecosystem
Great Horned Owls are the most common owl in Yellowstone National Park. They are protected under the Migratory Bird Treaty Act, and can’t be kept as pets without special permits. Permits are required even to have their feathers.
Great horned owls are fearsome predators, eating rodents, rabbits, all manner of birds, frogs, snakes, and whatever else they can catch. They even eat even other predators like falcons, cats, weasels, and other owls. Great horned owls are one of the few predators that eat porcupines, knocking them out of trees and killing them when they are stunned after their fall.
The talons of a great horned owl can clamp with 28 pounds of force, which can sever the spine of their prey.
At the Sanctuary, we feed our great horned owls a variety of whole small animals, mostly rats and mice.
BEHAVIOR & Lifespan
In the wild, great horned owls have an average life expectancy of 13 years; the oldest great-horned owl on record was at least 28.