Lek fidelity of male Arctic charr

Abstract

For males, the reproductive advantage of joining a lek varies among leks; consequently, males should join the lek yielding the highest fitness. When males experience low reproductive opportunities at one lek, it may pay to move to another. By observing tagged male Arctic charr (Salvelinus alpinus L., 1758) at three different lek sites within one lake, we examined whether males moved between leks. Some movement was observed, especially between closely located leks, but fish length and spermatocrit, traits indicative of reproductive success, were unrelated to whether or not individuals moved between leks. Little to no movement was observed between more distantly separated leks, even though the costs associated with movements across the relatively short distances between these leks should be low. This suggests that individuals, rather than moving from leks where they have low reproductive success, are relatively stationary. The lek fidelity documented in the present study may be important for production of local genetic differences between Arctic charr leks. Our results suggest that males with low reproductive success may enhance their fitness by means other than dispersal, e.g., by associating with relatives to increase inclusive fitness.