Divergent sexual selection on birdsong: a reply to Byers

► We address specific criticisms of Byers (2011, Animal Behaviour, 82, e1–e3).
► We clarify potential areas of confusion in Collins et al. (2009, Proceedings of the Royal Society B, 276, 585–590).
► We conclude that blackcap populations differ in the pressures driving male song evolution.
► We hypothesize that male competition may be stronger in resident populations of song birds.