This ptarmigan was clinging to the side of a boulder on the flank of Cairngorm Mountain after two days of heavy snow. It is moulting from winter to summer plumage, providing superb camouflage in combination with lichen on the boulder. Under overcast light, white plumage, snow and background virtually merge into one.
F/8, 1/800th second, ISO 400
Accepted: Hoylake 2018