Although it is North America’s largest owl with a wingspan up to 60 inches, the great gray owl is mostly fluff, weighing only 2-3 pounds, about half the weight of a snowy owl. In North America, it ranges from Alaska south to the northwestern US and east to the Great Lakes. Great gray owls also inhabit northern Europe and Russia. It is a year-round resident of secluded wilderness areas, preferring coniferous forests in the far north and mountainous areas in the west. It has not been spotted in large numbers in the American northeast since 1978-1979, when hundreds of owls were driven from their home ranges by food shortages.
The great gray owl’s main prey is small rodents like mice and squirrels. The feathers of its facial disc channel sound to its ears, which are surrounded by bony cups, allowing it to locate prey, even beneath 2 feet of snow in the dark. Upon hearing its prey, the owl glides from its perch and snatches the food with its talons, breaking through layers of snow if necessary. In the northern winter, the great gray owl largely has the rodent population to itself, which is fortunate, since adults will consume up to a third of their body weight daily.
Usually nesting in abandoned hawk and eagle nests or on tree stumps, great gray owls are devoted parents. When prey is scarce, females will starve themselves to maximize food for their chicks, losing up to a third of their own body weight. Their sacrifices are rewarded with remarkably high breeding success rates. Breeding pairs in North America successfully fledge 70-80 percent of their young.
February 25, 2011