BLACK-HOLE MODELS OF UNGULATE LEK SIZE AND DISTRIBUTION

Models of lek breeding based an female preferences for mating with hig h quality males have predicted that leks should be evenly distributed at distances approximating the diameter of female home ranges, and emp irical studies have cited lek distribution in support of these models. In the 'black hole' model of lek evolution, leks arise because cluste rs of male territories retain mobile females; female mating preference s are not assumed. Here this model is extended to include sufficient s pace and animals for multiple leks to form, and it is used to generate predictions about the size and spacing of leks in different populatio ns. Like models based on female choice, black hole models predict that leks will be evenly spaced at distances of approximately one female h ome range diameter, that lek size will increase with increasing male d ensity, and that females will be concentrated near the centre of leks where male territories will be smallest. The addition of female copyin g to the model decreases the tendency for leks to form, but this influ ence is mitigated by an upper limit on harem size. Since similar lek d istributions are predicted by contrasting models, the even distributio n of leks may imply some mechanism causing females to aggregate at the largest accessible cluster of territories, but does not clarify the n ature of this mechanism. (C) 1996 The Association for the Study of Ani mal Behaviour