An area of ground divided into territories that are vigorously defended by males for purposes of sexual display and mating during the breeding season. Such a system occurs in various bird species, for example the black grouse and peafowl, and also in some mammals. The most dominant males occupy the smallest territories at the centre of the lek, where they are most likely to attract and copulate with visiting females. The peripheral, and larger, territories are occupied by subordinate males, who have less mating success. Over successive breeding seasons, the younger subordinate males gradually displace older individuals from the most desirable territories and become dominant themselves. The lek territories contain no resources of value to the breeding female, such as food or nesting materials, although males of some species may construct bowers or similar structures used in their display.