The winter ptarmigan (the “p” is silent) can be very difficult to see, especially in low light.
Apart from the small dark beak and eyes, they are incredibly white. I have at times mistaken them for lumps of snow, especially when they are on the roads; groups of them will land there.
Completely adapted to their environment, they are white in the winter and a mottled brown in the summer. How many ptarmigan do you see in the photo?