Sorry guys, none of the books I have on either Afican birds or birds of prey have any really good images of Saker Falcons. However, the illustrations in both the books I do have which deal with either eagles, hawks, and falcons or the world or African birdlife do not show the Saker Falcon in any way as spotted on the breast as this falcon. Now again, regardng the Gyrfalcon, I have no photographs of the color phase it appears to be, but in both the NATIONAL GEOGRAPHIC Complete Birds of North America, edited by Jonathan Alderfer, Copyright 2006, National Geographic, Washington D.C. and NATIONAL AUDUBON SOCIETY The SIBLEY Guide to Birds, Written and Illustrated by David Allen Sibley, Copyright 2000, Chanticleer Press, Inc. New York, their illustration of the "Gray juvenile (first year)" is almost identical to your photograph. So that would be my best guess.
this is almost certainly a saker falcon. their plumage varies greatly across their range from eastern europe to china. gyr and saker falcons are very closely related and some believe that the altai race of saker falcon is really a subspecies of gyr falcon.
it may also be a man made hybred of gyr and saker but looking at this bird seems unlikely.
