CONCLUSION
We performed a genome wide association study to investigate which genes
may underlie differences between red and yellow feathers in tinkerbirds.
We found an association with CYP2J19 on chromosome 8, to our
knowledge this is the first time such an association has been found with
feather colour across a natural avian hybrid zone, indeed the first timeCYP2J19 has been associated with red feather colour in a
nonpasserine bird. Asymmetric hybridisation suggests a preference for
red plumage in females that share the red trait, consistent with
converted carotenoids reflecting male fitness.