Gyrfalcons have a circumpolar distribution in the Northern Hemisphere, being found mainly in Arctic areas. In Europe they are resident in the High Arctic (except Svalbard where I guess the lack of small mammal prey prevents their establishment) and Iceland; they are also found in winter in much of Norway, northern Sweden and northern Finland. Their plumage varies in colour depending on where they're from - the northern European birds are medium grey above with bold barring below, Icelandic birds are a paler grey, and Gyrfalcons from Greenland are white with black barring on their wings. However there is overlap between the colour morphs, both geographically and in terms of the plumage colour and pattern. I've chosen a photo of a medium grey bird seeing as it's the most likey to be seen in Europe. The sexes look similar, and juveniles are dark brown above with coarse brown streaking below; they also have a pale blue-grey cere and feet compared to the adults' yellow. In flight they look a bit like larger, bulkier Peregrines with broader, blunter wings and slower, shallower wingbeats. Gyrfalcons' preferred habitat is tundra with patches of scrub and trees, mountains, sea coasts and river valleys.
I had a bit of a slow weekend during which I didn't really get as much done as I wanted on anything, including my bird paintings, due to having a snot-tastic cold. It's pretty much gone now though! I worked on this painting in bits but I'm not too keen on it, once again I think I've fudged the fine detail on the upperwings. Never really have time to do it justice and I haven't worked out any quick way to do it that looks any good.