the black grouse, lyrurus tetrix

action aggressively amazing back beak belly bill bird birds birdwatching black blackcock breast claw clawing courtship cruel death duel eyes face feather feathers fight fighter grouse head incredible lek lekking lyrurus mating moorland nature oboe one ornithology plumage plume red season spring struggle swamp sweden tail talon tetrix viciously violently widly wing wings wrestle