Markus Varesvuo / Willow grouse / Ptarmigan (Lagopus lagopus) pecking twig, Utsjoki, Finland, April.

Markus Varesvuo / Willow grouse / Ptarmigan (Lagopus lagopus) fluffed up perched in snow, Inari, Finland, February.

Markus Varesvuo / Willow grouse (lagopus lagopus) flock in flight in snow, Utsjoki, Finland, October.

Markus Varesvuo / Male Willow grouse / Ptarmigan (Lagopus lagopus) portrait, Inari Kiilopaa, Finland, February.

Markus Varesvuo / Willow grouse / Ptarmigan (Lagopus lagopus) flying, Inari Kiilopaa, Finland, February.

Markus Varesvuo / Willow grouse (Lagopus lagopus) perched on branch, Kiilopaa, Inari, Finland, January.

Markus Varesvuo / Willow grouse (Lagopus lagopus), Kiilopaa, Inari, Finland, January.

Markus Varesvuo / Willow grouse (Lagopus lagopus), Kiilopaa, Inari, Finland, January.

Markus Varesvuo / Willow grouse (Lagopus lagopus) Kiilopaa, Inari, Finland, January.

Markus Varesvuo / Willow Grouse (Lagopus lagopus) in flight over snowy landscape, Utsjoki, Finland April

Markus Varesvuo,Markus Varesvuo / Willow grouse (Lagopus lagopus) in winter plumage, Utsjoki, Finland, April.

Ben Hall,Ben Hall / Red grouse (Lagopus lagopus scotica) sitting in flowering heather, Peak District, UK, September

Sergey Gorshkov / Willow grouse / ptarmigan (Lagopus lagopus) pair in flight, Agapa River, Taimyr Peninsula, Siberia, Russia

Gerrit Vyn / Willow Ptarmigan (Lagopus lagopus) male standing on snow covered ground, vocalising in spring courtship. Males retain the white body plumage of winter plumage and molt the head and neck feathers to th...

Donald M. Jones / Willow Ptarmigan (Lagopus lagopus) trio in fall, transitioning to winter plummage, central Alaska

Mark Raycroft / Willow Ptarmigan (Lagopus lagopus) camouflaged on autumn tundra

Glenn Bartley / Willow Ptarmigan (Lagopus lagopus) male, Manitoba, Canada

Michael Quinton / Willow Ptarmigan (Lagopus lagopus) with fall plumage perching on branch, Alaska

Michael Quinton / Willow Ptarmigan (Lagopus lagopus) in winter plumage, Alaska

Michael Quinton / Willow Ptarmigan (Lagopus lagopus) with camouflaged winter plumage in snow burrow, Alaska

SCOTLAND: The Big Picture / Red grouse, (Lagopus lagopus scoticus), close-up of adult male in spring plumage, Scotland, UK, February.

SCOTLAND: The Big Picture / Red grouse, (Lagopus lagopus scoticus), adult with two juveniles on flowering heather moor in summer,Scotland, UK, August.

SCOTLAND: The Big Picture / Red Grouse (Lagopus lagopus scoticus) adult male on heather moor in falling snow, Scotland, UK.March

SCOTLAND: The Big Picture / Group of people protesting to raise awareness of Hen harrier (Circus cyaneus) persecution on Grouse moors. Boat of Garten, Cairngorms National Park, Scotland, UK. August 2017.

SCOTLAND: The Big Picture / Staff of OneKind animal welfare charity raising awareness of Mountain hare (Lepus timidus) persecution on Grouse Moors as part of Hen Harrier Day. Boat of Garten, Cairngorms National Park, Scotland, U...

Andy Sands / Red grouse (Lagopus lagopus scoticus) female on nest camouflaged, Upper Teesdale, Co Durham, England, UK, June

Andy Rouse / Red Grouse, (Lagopus lagopus), on wall, Yorkshire, UK

Andy Rouse / Red Grouse, (Lagopus lagopus), on wall at sunrise, Yorkshire, UK

Andy Rouse / Red Grouse, (Lagopus lagopus), on post at sunrise, Yorkshire, UK

David Tipling / Red grouse (Lagopus lagopus scotica) nest and eggs, Lochindorb, Speyside, Scotland, UK, May.

Ernie Janes / Red grouse (Lagopus scoticus) in snow, Yorkshire Dales, England, UK, November.

Sergey Gorshkov / Willow grouse (Lagopus lagopus) flock in flight, Taymyr Peninsula, Siberia, Russia . March

Sergey Gorshkov / Willow ptarmigans (Lagopus lagopus) Taymyr Peninsula, Siberia, Russia . March

Sergey Gorshkov / Willow ptarmigans (Lagopus lagopus) resting in snow, Russia. March

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) resting in snow, Taymyr Peninsula, Siberia, Russia. March

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) resting in snow, Taymyr Peninsula, Siberia, Russia. March

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, Taymyr Peninsula, Siberia, Russia. June

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, Taymyr Peninsula, Siberia, Russia. June

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) female in spring plumage, Taymyr Peninsula, Siberia, Russia. June

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) Taymyr Peninsula, Siberia, Russia. June

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, Taymyr Peninsula, Siberia, Russia. June

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, in snow, Taymyr Peninsula, Siberia, Russia. June

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, calling at sunrise, Taymyr Peninsula, Siberia, Russia. May

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, in flight at sunset, Taymyr Peninsula, Siberia, Russia. May

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) male in spring plumage, Taymyr Peninsula, Siberia, Russia. May

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) males in spring plumage Taymyr Peninsula, Siberia, Russia. May

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) males in spring plumage fighting Taymyr Peninsula, Siberia, Russia. Sequence 9 of 9. May

Sergey Gorshkov / Willow ptarmigan (Lagopus lagopus) males in spring plumage fighting Taymyr Peninsula, Siberia, Russia. Sequence 8 of 9. May