It’s very exciting to see the publication today in Current Biology of our paper that describes the genomic basis of the bill colour variation in the two sub-species of the long-tailed finch. This is one of the key questions that I have been working towards with Daniel Hooper since 2015. Since our first field trip together to the Top End of Australia, Daniel has examined the genome sequence of over 1,200 individuals from across the wild range of the birds, and captive bred hybrids in the laboratory (many of which were sampled and bred by Callum McDiarmid). The cutting edge genomics has been completed with input from Peter Andolfatto, Frank Chan and Marek Kucka; the biochemistry of the carotenoids underlying the yellow and red bills was unravelled by Geoff Hill, Matthew Powers, and Nicholas Justin; and finally the work examining the fine anatomy of the retina was done by Nathan Hart, who demonstrated that even though the yellow-billed birds don’t make red carotenoids to put in their bills, they do still make them to use in the oil droplets that are used to filter light in the retina. It’s been super cool to work with all these amazing people to complete this huge study. The scale of the work can be seen in Fig 1 from the paper below that shows the sites that were sampled in the wild (E) and the variation in colour across them (F) and the lab-bred hybrids (D). The full paper can be found here