“…Birds possess various pigment classes, for instance carotenoids, pterins, porphyrins, psittacofulvins and melanins (McGraw, 2006;Hill and McGraw, 2006), and various mechanisms of structural colouration, namely thin films, multilayers, photonic crystals, keratin spongy nanostructures and nanofibres (e.g. Durrer, 1977;Shawkey et al, 2003;Shawkey et al, 2006;Yoshioka et al, 2007;Doucet and Meadows, 2009;Prum et al, 2009;Stavenga et al, 2010;D'Alba et al, 2011). The predominant location of colouration is the feathers, often either the barbs or the barbules.…”