Black grouse males facing off on a lekking site, Estonia

The lek side story. Black grouse males, Estonia

Before sunrise, the moorland clock punches in—and the dance floor opens. Male black grouse don't send invites; they boom them. Welcome to lekking season, where romance is competitive, noisy and strictly outdoors.

Each spring, male black grouse gather at traditional sites called leks. They fan out their lyre-shaped tails, drop their wings, puff up their white undertail coverts and produce a low, bubbling 'roo-kooing' call. They also hiss and posture at rivals. No pecking order? There is one—front-row spots usually belong to the most dominant males. Females arrive quietly, watch the show and choose. Only a few top performers win most of the matings. It's survival of the flashiest.

Lekking peaks at dawn from April to May in the United Kingdom and other parts of Eurasia. After mating, females nest alone and raise the chicks without help. The males? They're off the stage until next season. In short, it's a spring spectacle—where love is loud, rivals ruffle feathers and the early bird really does get the girl.