Great Grey Owl

The great grey owl, Strix nebulosa, stands as the world's largest owl by length. This majestic bird is recognized by its large rounded head, grey face, and piercing yellow eyes encircled by darker plumage. Its underparts are a lighter shade adorned with dark streaks, while the upper parts boast a grey hue with pale bars. Notably lacking ear tufts, the great grey owl possesses the most expansive facial disc of any raptor, and a distinctive white collar, reminiscent of a "bow-tie," sits just below its beak. The species' long tail, tapering to a rounded end, contributes to its impressive size, which is somewhat exaggerated by its voluminous feathers.

Identification Tips

Adult great grey owls can be identified by their lack of ear tufts and the largest facial disc among raptors. They exhibit a white "bow-tie" below the beak and a long, rounded tail. Males are typically smaller than females, a common trait among owl species. The great grey owl's call is a deep, rhythmic series of 'who's, primarily associated with territorial claims or communication with offspring.

Habitat

The great grey owl favors the dense coniferous forests of the taiga for breeding, often near open spaces such as meadows or bogs. In some regions, like Oregon and California, they have adapted to nesting in mixed oak woodlands.

Distribution

This owl is a permanent resident across the Northern Hemisphere, from North America to Eurasia. It breeds from Quebec to the Pacific coast and Alaska, and across northern Asia from Finland and Estonia to Russia. Some populations may move southward when prey is scarce.

Behaviour

The great grey owl is a patient hunter, often swooping down from a perch or flying low to capture prey. They are known to hunt primarily during the night, dawn, and dusk. Their hunting prowess is aided by their exceptional hearing, allowing them to detect prey beneath deep snow.

Song & Calls

The adult's call is a deep 'who' sound, while the young may produce various chatters, shrieks, or hisses. Tame individuals may emit higher-pitched hoots when fed by humans.

Breeding

Great grey owls do not construct their own nests, instead opting for previously used nests of large birds or natural cavities. They may breed from March to May, with clutch sizes typically around four eggs. The incubation period lasts about 30 days, and the young are dependent on their parents for several months post-fledging.

Diet and Feeding

The great grey owl's diet is predominantly small rodents, with the specific prey varying by region and availability. They are capable of detecting and capturing prey moving under significant snow cover, a hunting technique known as "snow-plunging."

Conservation status

The great grey owl is currently listed as Least Concern by the IUCN. However, habitat loss due to timber harvesting poses a significant threat to the species, along with other dangers such as rodenticides, vehicle collisions, and diseases like the West Nile Virus.

Territorial behavior

Great grey owls are not highly territorial and are less aggressive than other large predatory birds. They do not defend large nesting territories or hunting grounds through aggression, although females can be protective of their eggs and young.

Provincial bird

The great grey owl holds the honor of being the provincial bird of Manitoba.

Captivity

As of 2016, a few great grey owls are kept in captivity in Oregon and California, primarily in wildlife rehabilitation centers and museums. They are also commonly found in European zoos.

Similar Species

The great grey owl can be distinguished from other species by its large size, lack of ear tufts, and the unique white "bow-tie" below its beak.