Monday, November 18, 2013

Great Grey Owl - The Phantom of the North

The northern boreal forests of North America, Europe, and Asia are home to an extraordinary owl - the Great Grey Owl (Strix nebulosa). It has a wingspan of 5 feet and can stand as tall as 2 feet in height. Its wingspan is the largest of any owl and its the largest owl in North America. The females are larger than the males. These owls do not make their own nests but rather occupy abandoned nests left behind by other birds of prey. They can lay a clutch of 5 eggs which hatch after a 29 day incubation period, and the chicks become independent around five months old. During the incubation period the male will bring food to the female and when food is scarce the female Great Grey Owl will often starve herself in order to feed her chicks. They become aggressive during nesting and will attack anything that comes near their nest. They have an average lifespan of 7 years in the wild, however in captivity they have been reported to live up to 40 years.

Great Grey Owl's Nest

Strix nebulosa
Strix nebulosa
Their diet mainly consists of small rodents such as voles, pocket gophers, and mice but they also hunt other small mammals such as squirrels, young rabbits, weasels and even small birds, ducks, and grouse. They usually spot their prey from atop a perch. The owl's keen hearing enables it to pinpoint its prey even when its prey is beneath the snow. The owl will capture its prey by swooping down and pouncing into the snow with its feet, grabbing its prey and swallowing it whole. They usually hunt at dawn and dusk, however they are most active at night.


Though not endangered in most places, Great Grey Owls are prone to habitat loss due to deforestation. In 1980, the species was placed on California's endangered species list after a decline in population.

Great Grey Owl in Yosemite National Park

 Did you know? Great Grey Owls only migrate when food is scarce.


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