Black grouse male calling at lek site in Kuusamo, Finland

Spring is lekking season for the black grouse. In the early morning, the male birds gather on lek sites, often a patch of open ground, to put on a show for the ladies. The males flash their white tail feathers, make cooing and hissing noises, jump in the air and pick fights with each other – all to show their dominance to the watching hens. (Hens are smaller and have grey-brown feathers.) When a hen picks out the male she likes, the two fly off to mate and then go their separate ways.
© Oliver Smart/Alamy