Bird Lek Mating
Lekking is a curious variation on promiscuous mating. This word of Swedish derivation, describes a pattern of mating behavior seen only in a small number of birds around the world. In North America its chief practitioners are Greater and Lesser Prairie-Chickens, Sharp-tailed Grouse, Sage Grouse, and Buff-breasted Sandpipers.
During the mating season, the males of lekking species gather into small clusters of territories, called leks, or arenas. Each male defends a territory within the lek although the area may only be a few yards across. Thirty or more males can gather at a large lek. They display with frantic intensity, sometimes oblivious to most everything around them (though their intensity increases when females are present).
Females visit the lek and wander among the displaying males as if comparing their virtues. Eventually a female accepts the advances of a particular male and mates with it. Usually only a few males out of all those present on the lek ever successfully mate. The female then lays its eggs in a nest that may be distant from the lek and that will never be visited by the chosen male.
Left: Lekking species, like the Sage Grouse shown here, reserve mating activity to traditional lekking grounds. In these birds, incubation and parental care is left to the females.