Figure 1.

Tenure as an alpha male lance-tailed manakin showed a positive but nonlinear relationship with LRS. (a) The smooth function in a generalized additive model (GAM) describing the relationship of final alpha tenure (total years in the alpha role) to chicks sired in a male's lifetime. (b) Predicted values of LRS from this model for males of varying alpha tenure derived. Solid lines indicate the main estimated values of the smoothing parameter in (a) and of predicted success in (b), and dashed lines show ±1 s.e. of these values. Open circles in (b) represent observed LRS values for males with completely observed alpha tenure (n = 50), and are jittered to visualize overlapping points.