Figure 1.

(a) The bimodal distribution of beak sizes for G. fortis at El Garrapatero in 2004 (white bars, females; black bars, males). Bimodality has been inferred for this population by statistical comparison of fits with unimodal and bimodal distributions (Hendry et al. 2006). (b) Representative small morph (left) and large morph (right) birds; both are mature males caught at the same time in the same mist net. (c) A large ground finch (G. magnirostris) and the same large morph G. fortis shown in (b). (d) A small ground finch (G. fuliginosa). Scale bar=5 mm. Photo credits Andrew Hendry.