Wildlife Chronicles

THE GYRFALCON by Peter Cunningham

If there is one bird whose acquaintance I would like to make ere I "slip the surly bonds of earth" it is the glorious Gyrfalcon. This arctic predator is a frequent vagrant to the Outer Hebrides but I have never in my fifty years here been lucky enough to behold one. Last week I received word of a large grey bird of prey near Bragar but it was not around the next day for me. Like a few other species the Gyrfalcon occurs in different colour phases, three in this case. Those nesting in Greenland are pure white while Icelandic ones are pale to dark grey and those in Finland and Russia dark grey. It is the Greenland birds which migrate south annually in winter (and who would blame them?) mainly to Shetland and Orkney and they are so scarce on mainland Scotland that some birdwatchers would brave the Minch just get a glimpse of a Gyrfalcon of any colour. "The white plumage of the Greenland Falcon may be said to be "protective", not that so powerful a bird needs protection from enemies, but that its plumage in a land of snow gives it a degree of invisibility which enables it to approach its prey and so obtain food." So writes T.A. Coward in volume three of "The Birds of the British Isles" (1920). He adds in terms typical of his time "Owing to its magnificent powers of flight, the visiting Iceland or Greenland Falcon avoids the gun more easily than some of the other birds of prey; it is not uncommon to hear of "white" falcons seen but not "obtained", most of which were, probably, Greenland birds."

It is the largest of our falcons, nearly two feet or 60cm in length and preys on Grouse and sea birds which it pursues, unlike the smaller Peregrine, close to the ground. It differs from the latter also in having no pronounced, dark moustachial stripes and head. How it got its Gaelic name, Gearr Sheabhag, is a mystery.

Carl von Linnã´, who drew up an international binomial system of naming birds in 1758, gave this falcon the scientific name of "Hierofalco gyrfalco" which as knowledge of genetical relationships improved was changed to "Falco rusticolus" which now covers all three phases. In the meantime J.F. Gmelin of a distinguished family of German scientists was credited with giving the Greenland Falcon the specific trinomial "H. islandus candicans" which is now obsolete.

If anyone should see a large, pale bird of prey, whatever it is called, I shall be most grateful for information leading to its sighting by me.