Wild Wonders of Europe / E. Haarberg / Male Black grouse (Tetrao tertrix) displaying, expiring warm air on a cold morning, Bergslagen, Sweden, April 2009

Sergey Gorshkov / Minden / Northern Goshawk (Accipiter gentilis) feeding on Black Grouse (Tetrao tetrix) female in winter, Finland

Markus Varesvuo / Two male Black grouse (Tetrao / Lyrurus tetrix) fighting at lek. Utajarvi, Finland, April.

Markus Varesvuo / Black Grouse (Lyrurus tetrix) male displaying with bokeh effect in the foreground, Liminka, Finland, March

Markus Varesvuo / Black Grouse (Lyrurus tetrix) male displaying with bokeh effect in the foreground, Liminka, Finland, March

Sven Zacek / Black Grouse (Tetrao tetrix) two males facing off on a lekking site, Varumaa county, Southern Estonia. April.

Erlend Haarberg / Black grouse (Lyrurus tetrix), male calling early in the morning, Norway. May.

SCOTLAND: The Big Picture / RF - Black Grouse (Tetrao tetrix) male peforming flutter jump display on lek, Cairngorms National Park, Scotland, UK.May (This image may be licensed either as rights managed or royalty free.)

SCOTLAND: The Big Picture / RF - Black Grouse (Tetrao tetrix), two males fighting on lek , Scotland, UK.April (This image may be licensed either as rights managed or royalty free.)

Sergey Gorshkov / Black Grouse (Tetrao tetrix) males fighting at lek in the snow, Tver, Russia. April

Markus Varesvuo / Female Capercaillie (Tetrao urogallus) with newly hatched chick on nest, Kuhmo, Finland, June.

Markus Varesvuo / Female Capercaillie (Tetrao urogallus) ready to mate, Vaala, Finland, May.

Markus Varesvuo / Female Black grouse (Tetrao / Lyrurus tetrix) perched in tree covered in snow, Inari Kiilopaa, Finland, January.

Markus Varesvuo / Black grouse (Tetrao / Lyrurus tetrix) flock flying in snow, Suomussalmi, Finland, January.

Markus Varesvuo / Female Black grouse (Tetrao / Lyrurus tetrix) perched in Willow feeding, Utajarvi, Finland, May.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) flying, Jalasjarvi, Finland, April.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) display jumping, Vaala, Finland, May.

Markus Varesvuo / Capercaillie (Tetrao urogallus) chicks huddled together, Kuhmo, Finland, June.

Markus Varesvuo / Male Black grouse (Tetrao / Lyrurus tetrix) flying, Utajarvi, Finland, April.

Markus Varesvuo / Female Capercaillie (Tetrao urogallus) with three chicks, Kuhmo, Finland, June.

Markus Varesvuo / Golden eagle (Aquila chrysaetos) plucking Capercaillie (Tetrao urogallus) Kuusamo, Finland, April.

Markus Varesvuo / Male Black grouse (Tetrao / Lyrurus tetrix) with breath visible in cold, Liminka, Finland, March.

Markus Varesvuo / Two male Black grouse (Tetrao / Lyrurus tetrix) fighting, Utajarvi, Finland, April.

Markus Varesvuo / Two male Black grouse (Tetrao / Lyrurus tetrix) fighting, Kuusamo, Finland, April.

Markus Varesvuo / Male Black grouse (Tetrao / Lyrurus tetrix) in snow, Utajarvi, Finland, May.

Markus Varesvuo / Two Capercaillie (Tetrao urogallus) chicks, Vaala, Finland, June.

Markus Varesvuo / Male Black grouse (Tetrao / Lyrurus tetrix) portrait, Utajarvi, Finland, May.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) head portrait with breath visible in cold air, Kuusamo, Finland, March.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) looking up, Kuusamo, Finland, March.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) displaying, Jalasjarvi, Finland, April.

Sven Zacek / Black grouse (Tetrao tetrix) males lekking at sunrise, Southern Estonia, April.

Konstantin Mikhailov / Pallas's sandgrouse (Syrrhaptes paradoxus) group of four flying against blue sky, Gobi Desert, Mongolia, August.

Andy Trowbridge / Capercaillie (Tetrao urogallus) male displaying in Scots pine tree (Pinus sylvestris) Southern Norway. May.

Markus Varesvuo / Black grouse (Lyrurus tetrix) mating in snow, Utajarvi, Finland, May.

Markus Varesvuo / Black grouse (lyrurus tetrix) female and chick at nest, Vaala, Finland, June.

Markus Varesvuo / Capercaillie (Tetrao urogallus) male calling with female, Jalasjarvi, Finland, April

Markus Varesvuo / Black Grouse (Tetrao tetrix) displaying with breath vapor at dawn, Utajarvi, Finland, April

Markus Varesvuo / Black Grouse (Tetrao tetrix) female on frosty branches, Kuusamo, Finland April

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) flying in woodland, Vaala, Finland, April.

Markus Varesvuo / Male Capercaillie (Tetrao urogallus) flying in woodland, Vaala, Finland, April.

Markus Varesvuo / Capercaillie (Tetrao urogallus) in flight, Kuusamo, Finland, Januaryary

Markus Varesvuo / Two Black Grouse (Tetrao tetrix) hens in snowy tree, Kuusamo, Finland, January

Andrew Parkinson / Male Capercaillie (Tetrao urogallus) displaying at photographer Andy Parkinson whilst on assignment for 2020VISION, Cairngorms National Park, Scotland, UK, March.

Markus Varesvuo / Capercaillie (Tetrao urogallus) close up of male calling in the snow, Vaala Finland April