Fig. 4.

Allopatric tinkerbirds respond significantly more than sympatric tinkerbirds to heterospecific playback. (A) Bar charts indicating responses to playback of heterospecific song to both species, illustrating significantly greater responses in populations in allopatry (and effective allopatry). (B) Males respond significantly more than females to conspecific playback when they are in breeding condition, whereas there is no difference in responses between the sexes when they are not breeding.