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Psittacofulvin composition of red feathers from parrots found in each of the three main parrot families. Standard errors are shown above each bar, which denotes the species means (nZnumber of species) for each pigment type within a family. In separate two-way analyses of variance for the five psittacofulvins, we found no effect of sex (all pO0.07), family (all pO0.15), or sex-by-family interaction (all pO0.35) on the percentage (a) of total pigments that each comprised. We did, however, find that there was a significant effect of sex (F 1,39 Z4.0, pZ0.04) and family (F 2,39 Z7.4, pZ0.02) on (b) total featherpigment concentration (no sex-by-family interaction; pO 0.3). Post hoc tests revealed that male feathers contained more pigments than females (Fisher's PLSD, pZ0.01) and that lory feathers contained more than feathers of psittacids and cockatoos (Fisher's PLSD, both p!0.02; pZ0.25 for pairwise comparison between psittacids and cockatoos). (c) Representative UV–VIS reflectance spectra for the red feathers of the three species for which HPLC chromatograms are shown in figure 1. See Siefferman & Hill (2003) for these spectrophotometric methods.  

Psittacofulvin composition of red feathers from parrots found in each of the three main parrot families. Standard errors are shown above each bar, which denotes the species means (nZnumber of species) for each pigment type within a family. In separate two-way analyses of variance for the five psittacofulvins, we found no effect of sex (all pO0.07), family (all pO0.15), or sex-by-family interaction (all pO0.35) on the percentage (a) of total pigments that each comprised. We did, however, find that there was a significant effect of sex (F 1,39 Z4.0, pZ0.04) and family (F 2,39 Z7.4, pZ0.02) on (b) total featherpigment concentration (no sex-by-family interaction; pO 0.3). Post hoc tests revealed that male feathers contained more pigments than females (Fisher's PLSD, pZ0.01) and that lory feathers contained more than feathers of psittacids and cockatoos (Fisher's PLSD, both p!0.02; pZ0.25 for pairwise comparison between psittacids and cockatoos). (c) Representative UV–VIS reflectance spectra for the red feathers of the three species for which HPLC chromatograms are shown in figure 1. See Siefferman & Hill (2003) for these spectrophotometric methods.  

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In many birds, red, orange and yellow feathers are coloured by carotenoid pigments, but parrots are an exception. For over a century, biochemists have known that parrots use an unusual set of pigments to produce their rainbow of plumage colours, but their biochemical identity has remained elusive until recently. Here, we use high-performance liquid...

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... Psittacofulvins are thus condition dependent and involved in a trade-off between ornamentation and immune function [14]. Since psittacofulvines might be costly to produce [15], they could also act as an honest signal of individual quality. However, contrary to carotenoids, psittacofulvines are endogenously synthesized and do not signal nutritional state or foraging ability. ...
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... For example, bird feathers exhibit only saturated structural blues and greens but not reds (23,24). For instance, even the "red" feathers of parrots (Aves: Psittaciformes) have a magenta appearance, as they exhibit substantial blue and green components in the reflectance spectrum (25). In addition, the scales of longhorn beetles (26) and natural cuttlefish ink (27) have structural colors spanning the visible spectrum, with the exception of saturated red (closest being magenta). ...
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... Although bright colorations are most often produced by carotenoids, notable exceptions have been found across birds. Psittacofulvins, turacin, and spheniscins have been identified as the source of plumage colors in parrots, turacos, and penguins (respectively) (Krukenberg 1882;Dyck 1992;McGraw & Nogare, 2005;Hill and McGraw 2006;Thomas et al., 2013). However, in several species of parrots, levels of carotenoids circulating in the blood at time of feather growth were found to be comparable to those in other bird groups that do express carotenoids in their feathers, including metabolically derived compounds (McGraw & Nogare, 2005). ...
... Psittacofulvins, turacin, and spheniscins have been identified as the source of plumage colors in parrots, turacos, and penguins (respectively) (Krukenberg 1882;Dyck 1992;McGraw & Nogare, 2005;Hill and McGraw 2006;Thomas et al., 2013). However, in several species of parrots, levels of carotenoids circulating in the blood at time of feather growth were found to be comparable to those in other bird groups that do express carotenoids in their feathers, including metabolically derived compounds (McGraw & Nogare, 2005). These levels have been suggested to indicate that at least parrots have the physiological potential for carotenoid deposition in feathers, but preferentially do not. ...
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... Two pigment types are found in the plumage of parrots: black, brown and redbrown colours in the plumage, claws, beaks and eyes are caused by the melanin pigments, whereas green, blue, purple, red, yellow, pink and orange plumage colours are caused by psittacofulvin pigments [49,50]. Parrots are the only species on earth known to produce psittacofulvin pigments and the expression of these pigments is controlled genetically and not environmentally [49,[51][52][53]. Five psittacofulvin pigments across 27 parrot genera were identified by [53]. ...
... Parrots are the only species on earth known to produce psittacofulvin pigments and the expression of these pigments is controlled genetically and not environmentally [49,[51][52][53]. Five psittacofulvin pigments across 27 parrot genera were identified by [53]. Plumage colour is created by the combination of pigment and structural modifications in the barbs of parrot feathers [54]. ...
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... It has been successfully applied to detect carotenoids and psittacofulvins. [7,8] However, one of the drawbacks of this technique is that it requires extraction of the analyte to yield results. Moreover, it usually employs a relatively large amount of material for the analysis, which poses limitations where sample availability is restricted. ...
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... Fortunately, new advances in spectrometry and HPLC have made possible a significant improvement in this field of knowledge [47,58]. Thus, during the last 15 years, several research groups worldwide have characterised the nature (and even the concentrations) of carotenoids in blood and feathers, mainly in finches [59,60] and parrots [33,61]. All the reported results show that the most important carotenoids contributing to the red-orange-pink colours in feathers are: canthaxanthin, astaxanthin, zeaxanthin and carotene (including its derivatives). ...
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... 3,4 However, some birds utilize other unique pigments in their plumage, including porphyrins in raptors, 5 bustards, and turacos (e.g. turacin, turacoverdin), 6 pterin-like compounds in penguins, 7 and psittacofulvins in parrots 8 ; in these unusual instances, the chemical nature, mechanisms, and functions of these pigments are poorly known. ...
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Among the most ornate animal traits in nature are the angle-dependent (e.g. iridescent) structural colors of many fishes, damselflies, birds, beetles, and butterflies. Though we now have a solid understanding of the mechanisms that create angle-dependent coloration in several groups, we know little about whether pigmentary colors reflect light in an angle-dependent fashion or if similar or different mechanisms govern angle-dependent reflectance from pigmentary versus structural colors. Here for the first time we describe non-iridescent angle-dependent coloration from the tail and wing feathers of several parrot species (Aves: Psittaciformes). We employed a novel approach—by calculating chromatic and achromatic contrasts (in just noticeable differences, JNDs) of straight and angled measurements of the same feather patch—to test for perceptually relevant angle-dependent changes in coloration on dorsal and ventral feather surfaces. We found, among the 15 parrot species studied, significant angle dependence for seven of our eight feather JND parameters. We then measured micro-scale features on each side of feathers, including size and color of barbs and barbules, to attempt to predict interspecific variation in degree of angle-dependent reflectance. We found that barb height, plumage-color type (e.g. melanin, structural), and differences between barb-barbule coloration (measured using Euclidean distances) were the strongest predictors of angle-dependent coloration. Interestingly, there was no significant phylogenetic signal in any of the angle-dependence models tested. These findings deepen our views on the importance of microscopic feather features in the production of directional animal coloration, especially in tissues that are colored predominantly by pigments and appear to be statically colored.