Altai falcon

The Altai falcon ("Falco cherrug altaicus"?) is a large falcon of questionable taxonomic position. It is often considered to be a subspecies of the saker falcon ("Falco cherrug"). It used to have a high reputation among Central Asian falconers. It is uncertain whether the bird is a saker subspecies or a hybrid.
Distribution and taxonomy.
The Altai falcon breeds in a relatively small area of Central Asia across the Altai and Sayan Mountains. This area overlaps with the much larger breeding area of the saker falcon "(Falco cherrug)". It appears that Altai falcons are either natural hybrids between sakers and gyrfalcons "(Falco rusticolus)", or rather the descendants of such rare hybrids backcrossing into the large population of sakers.
So far, molecular genetic studies cannot prove or falsify the hybrid hypothesis. Gyrfalcons are rare winter vagrants to the Altai falcon's range. The high altitude cold grasslands of the region constitute habitat intermediate between typical saker habitat (temperate lowland steppes) and typical gyrfalcon habitat (arctic tundra). These two species of falcons also easily hybridise in captivity.
Thus the Altai falcon is tentatively considered to be a saker subspecies "Falco cherrug altaicus". It tends to be larger than typical sakers and has red-backed, brownish and greyish colour varieties.