Gyrfalcon
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| Falco rusticolus Linnaeus, 1758 |
The Gyrfalcon (Falco rusticolus), also spelled Gyr Falcon (The 'g' is pronounced as "j" in "jar"), is the largest of all falcons. The Gyrfalcon breeds on Arctic coasts and islands of North America, Europe and Asia. It is mainly resident, but some Gyrfalcons disperse more widely after the breeding season, or in winter.
Its male is sometimes called a gyrkin or similar and is one-third smaller than the female.
The name comes from French gerfaucon, and is written in mediaeval Latin as gyrofalco. The first part of the word may come from Old High German gîr (= modern German Geier) = "vulture", referring to its size compared to other falcons.
The Gyrfalcon is a bird of tundra and mountains, with cliffs or a few patches of trees. It lays 2-6 eggs on a cliff ledge nest.
This is the largest falcon, at more than 60cm long with a wingspan up to 130cm, similar to the Common Buzzard. The female is larger than the male.
This species is like a large Peregrine Falcon in general structure, but broader-winged and longer-tailed than the Peregrine. It usually hunts by horizontal pursuit, rather than the Peregrine's stoop from a height, and takes bird and small mammal prey such as Ptarmigans and lemmings.
[edit] In falconry
In medieval times, the Gyrfalcon was considered the king's bird. Due to its rarity and the difficulties involved in obtaining it, in falconry the Gyrfalcon was generally reserved for kings and nobles. Very seldom was a man of lesser rank seen with a Gyrfalcon on his fist.[citation needed]
Gyrfalcons are very expensive to buy, and thus owners and breeders may keep them secret to avoid theft. They tend to fly long distances, and falconers may fit a radio-tracker to aid recovery.[citation needed]
Wild Gyrfalcons are not much exposed to disease, and as a result have weak immune systems. As a result, many Gyrfalcons taken from the wild quickly die of disease. Several generations of captive breeding from the survivors causes selection for a stronger immune system and thus better resistance to disease. (Ref.[1], about a third of the way down the page)
[edit] Subspecies
Plumage is very variable in this species. Often adults have slate-grey back and wings, and young birds are browner. Sexes are similar. Greenland Gyrfalcons have white plumage, flecked with grey on the back and wings. Other geographical forms are varying intensities of grey in coloration: the Icelandic form is the palest, and Eurasian forms are considerably darker. Natural separation into regional subspecies is prevented by gyrfalcons' habit of flying long distances taking genes from one population into another. For example, one known mating of a pair of captive gyrfalcons produced a clutch of 4 young: one white, one silver, one brown, one black.
[edit] Other meanings
The Gyrfalcon Islands are a group of islets around 68° 55' west 59° 8' north in Ungava Bay in northeastern Canada.[2]
[edit] References
- BirdLife International (2004). Falco rusticolus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006. Database entry includes justification for why this species is of least concern.
