Queuing for territory positions in the lekking black grouse (Tetrao tetrix)

The importance of a central territory position as a determinant of male mating success in lekking species has been debated. The process by which a male can obtain a central territory has been especially lacking a quantitative analysis. We present a stochastic queuing model describing territory succession toward the lek center and apply it to a 8-year sequence of territory centrality measures on a black grouse Tetrao tetrix lek. The lek shows a value of intermediate queue discipline, which deviates significantly both from strict orderly queuing and from random ranking of males. Thus, high-ranking males are partly able to maintain their superior position over years, but queue-jumping is not excluded; especially because highly succesful males do not attempt to change their territory position toward the lek center. As a result of stochastic queuing, a central territory indicates an older than average male, as well as a male with a history of high fighting rates. These results are consistent with the hypotheses that territory position is an honest signal of male quality and that the long-term fighting effort and survival required to acquire a central territory may increase the reliability of the signal over that of short-term display effort. The impartial queue discipline, however, also leaves room for other male characteristics to play a role in determining individual mating success.