Great Grey Owls can be found in forests and near open areas such as meadows or bogs in Canada from Quebec to the Pacific coast, Alaska and Finland.
Their diet is mainly made up of small rodents. They mostly hunt voles, but will also eat weasels, squirrels, rabbits, rats & mice.
They do not build nests so either use nests of other large birds or use broken topped trees or cavities in trees and nest from March to May with 4 eggs in a clutch. After 3 to 4 weeks young jump or fall from the nest, but start to fly 1 to 2 weeks after. The male will hunt to feed the young until they are ready to hunt alone in the Autumn.
Deforestation & human disturbance have a detrimental effect to their population. Chemicals used to minimise rodent numbers can cause poisoning throughout the food chain. In the USA they are seen as a threatened species and are protected. There are laws in place governing logging in Great Grey Owl habitats to minimise loss of nest sites.
They have excellent hearing: their large facial disks, known as ‘ruffs’, focus sound. Asymmetrical ear placement also assists in locating prey, they can locate & capture prey moving beneath 60cm of snow!