Figure 1
Forecrown plumage (1) coloration was scored in: A) Pogoniulus pusillus pusillus ; and B) Pogoniulus chrysoconus extoni . We also scored: (2) supercilium; and (3) wing bar extent of yellow over black, from photographs, as shown of C) P. p. pusillus and D) P. c. extoni from allopatric populations. Samples, photographs scored and forecrown feathers were obtained from individuals that were phenotypically red-fronted (red circles) and yellow-fronted (yellow circles) across the contact zone (green line) in southern Africa (E).