Structure and composition of the courtship phenotype in the bird of paradise Parotia lawesii (Aves: Paradisaeidae)

High refractive index of melanin in shiny occipital feathers of a bird of paradise

“…6 The uniquely colorful breast feathers allows the breast color to switch sharply between yellow, blue and black as the bird moves, during the ballerina dance, which is performed as part of the courtship display. [7][8][9] The shiny occipital feathers have a similar function. Recent behavioral observations on the closely related Wahnes's Parotia demonstrate that the occipital feather reflections are sharply directed to the observing females during part of the courtship performance, presumably to impress a potential mate, viewing from an elevated position on a tree branch.…”

“…Recent behavioral observations on the closely related Wahnes's Parotia demonstrate that the occipital feather reflections are sharply directed to the observing females during part of the courtship performance, presumably to impress a potential mate, viewing from an elevated position on a tree branch. [6][7][8][9][10] To unravel the optical basis of the shiny occipital reflectors, we investigated the barbule anatomy. This revealed very regularly arranged melanosomes, i.e., small melanin rodlets, arranged in layers.…”

Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling

“…1 C and E). The breast feathers' unique, boomerangshaped cross-section, enveloped by a thin film, gives rise to threedirectional reflections that allow rapid switching between an orange, green, or blue color when the bird makes its moves (3,12).Whereas the essential features of the occipital feather reflections are well described by classical multilayer theory (13), the optical properties of the breast feathers have not yet been quantitatively treated, because the morphology of the barbules is too complex to apply analytical models (12). To unravel the reflection properties of the morphologically complex breast feathers as determined by spectrometry and imaging scatterometry, we applied an advanced computational approach, finite-difference time-domain (FDTD) modeling.…”

“…1 C and E). The breast feathers' unique, boomerangshaped cross-section, enveloped by a thin film, gives rise to threedirectional reflections that allow rapid switching between an orange, green, or blue color when the bird makes its moves (3,12).…”

“…Living isolated on Papua New Guinea and its satellite islands (1), the absence of predators has allowed these birds to become extremely specialized for female sexual selection (2). Male birds-of-paradise have evolved extravagant ornamental traits, with intricate sounds and ritualized sets of dance steps and movements accompanied by simultaneous elaborate feather movements, all combined in beautiful displays to win the favor of females (1)(2)(3)(4). Among the 39 species of birds-of-paradise almost all colors of the rainbow can be found, and often the males advertise themselves with brilliant, vivid colors framed within a jet-black background.…”