Male rank and optimal lek size

Widemo and Owens presented a model that calculates the expected copulation rates of males on leks of a range of sizes. They claim that a negative rela tionship between lek size and male mating skew will result in low-ranking m ales having greater optimal lek sizes than higher ranking rivals. Widemo an d Owens offered no proof of their claim, and their model assumes that the r ank of a male does not change as lek size increases, whereas in reality, ra nk may change as more males arrive. We present a general model that allows rank to change as lek size increases. We show that the crucial determinant of whether optimal lek size increases with male rank is whether relative co mpetitive differences increase with lek size. Contrary to the claim of Wide mo and Owens, the relationship between skew and lek size has no direct bear ing on the optimal levels of aggregation of males of different rank. We sho w that a negative relationship between skew and lek size can exist even whe n high-ranking males have the greatest optimal lek sizes.