Gyrfalcon

The Gyrfalcon, Falco rusticolus, stands as the largest falcon species, a majestic bird of prey that commands the skies of the Arctic. Its plumage is a tapestry of nature's artistry, ranging from a pure snowy white to a deep, earthy brown, with various morphs in between. This polymorphic bird exhibits sexual dimorphism, with the robust female out-sizing the male.

Identification Tips

To identify the Gyrfalcon, look for a large raptor with broad wings and a long tail. The male typically measures 48 to 61 centimeters in length, while the female is larger, ranging from 51 to 65 centimeters. The wingspan can extend from 110 to 130 centimeters. The plumage varies by region, with the white morph being most common in Greenland and darker morphs prevalent in Eurasia. Juveniles are darker and browner than the adults.

Habitat

The Gyrfalcon breeds on the Arctic coasts, tundra, and northern islands, favoring cliff faces for nesting. It is mainly a resident of these regions but may disperse more widely post-breeding or during winter.

Distribution

This bird's range spans the northern reaches of North America and the Eurosiberian region. Some individuals may embark on long-distance vagrancy beyond their typical Arctic habitats.

Behaviour

The Gyrfalcon is a solitary hunter, often seen in a horizontal pursuit of prey rather than the stooping dive of other falcons. It is known to kill most prey on the ground, even if initially captured in flight.

Breeding

Gyrfalcons do not construct their own nests but use existing structures such as cliff ledges or the abandoned nests of other birds. Clutch sizes range from 1 to 5 eggs, with the young fledging at 7 to 8 weeks and gaining independence at 3 to 4 months.

Similar Species

The Gyrfalcon can be distinguished from the Peregrine Falcon by its larger size, broader wings, and longer tail. It also lacks the well-defined malar stripe and cap of the Peregrine.

Diet and Feeding

The Gyrfalcon's diet is opportunistic, primarily consisting of birds and mammals. It preys on a variety of avian species, from small passerines to large waterfowl, and mammals such as Arctic ground squirrels and hares.

Conservation Status

The Gyrfalcon is currently listed as Least Concern on the IUCN Red List. It has adapted well to the high Arctic environment and is not significantly threatened by habitat destruction, although it has faced challenges from pollution and competition with Peregrine Falcons due to climate change.