The Great Grey Owl (Strix nebulosa) is an owl, which is the world’s largest species of owl by length. It is distributed across the Northern Hemisphere, and it is the only species in the genus Strix found in both Eastern and Western Hemispheres. The Great Grey Owl generally favors country with mix of dense forest for nesting and roosting, and open areas for hunting. In the north, mostly around bogs, clearings, and burns in extensive coniferous woods; in the west, mostly around meadows in mountain forest. The great grey owl’s diet is made up of around 80-90% small rodents. They mostly hunt voles, but will also eat gophers, weasels, squirrels, rabbits, rats and mice. They will also take some birds, including thrushes, grouse, and ducks. During the breeding season (roughly from March–July), males and females give a low-pitched series of resonating hoos that last for 6–8 seconds with about 30 seconds between calls. The male’s vocalization is lower pitched than the female’s. Adults also make a soft double hoot when defending territories or during food delivery. Here is a link so you can hear this owl too.