MALE TERRITORIALITY AND FEMALE CHOICE ON BLACK GROUSE LEKS

Two, not mutually exclusive, hypotheses for how female choice of males could explain male territory settlement patterns on leks have recentl y been proposed. First, the 'temporal spillover hypothesis assumes tha t females return to previously popular mating sites. If the previous o wner of such a popular site disappears it will pay other males to defe nd such areas of the lek. Second, the spatial spillover hypothesis ass umes that unsuccessful males gather around the most successful males t o achieve copulations from females with which top males for some reaso n fail to mate. In the black grouse, Tetrao tetrix, there were no indi cations of temporal spillover between successive years. While individu al males retained their popularity to some degree, there was no consis tency in the popularity df the same locations per se. Instead, some sp atial spillover is suggested by the fact that new territories in each season were established closer to the copulation centre than to the le k centre of the previous year. Furthermore, males close to the preferr ed males seemed to achieve copulations because of their proximity to s uch males. Successful males did not change their territorial position, but less preferred males tended to move closer to the lek centre fill ing the vacancies arising from any yearly mortality of males. While sp atial spillover explains only a minor proportion of matings, most fema les choosing males independent of their site, it may be the only chanc e for poor quality males to obtain matings.