The phylogenetic distribution of ultraviolet sensitivity in birds

Abstract

BackgroundColour vision in birds can be categorized into two classes, the ultraviolet (UVS) and violet sensitive (VS). Their phylogenetic distributions have traditionally been regarded as highly conserved. However, the complicated nature of acquiring spectral sensitivities from cone photoreceptors meant that until recently, only a few species had actually been studied. Whether birds are UVS or VS can nowadays be inferred from a wide range of species via genomic sequencing of the UV/violet SWS1 cone opsin gene.ResultsWe present genomic sequencing results of the SWS1 gene from 21 avian orders. Amino acid residues signifying UV sensitivity are found in the two most important spectral tuning sites 86 and 90 of Pteroclidiformes and Coraciiformes, in addition to the major clades, Palaeognathae, Charadriiformes, Trogoniformes, Psittaciformes and Passeriformes, where they where previously known to occur. We confirm that the presumed UVS-conferring amino acid combination F86, C90 and M93 is common to Palaeognathae and unique to this clade, despite available spectrometric evidence showing the ostrich retina to be VS.ConclusionsBy mapping our results together with data from previous studies on a molecular phylogeny we show that avian colour vision shifted between VS and UVS at least 14 times. Single nucleotide substitutions can explain all these shifts. The common ancestor of birds most likely had a VS phenotype. However, the ancestral state of the avian SWS1 opsin’s spectral tuning sites cannot be resolved, since the Palaeognathae are F86, C90 while the Neognathae are ancestrally S86, S90. The phylogenetic distribution of UVS and VS colour vision in birds is so complex that inferences of spectral sensitivities from closely related taxa should be used with caution.

Widespread cryptic dichromatism and ultraviolet reflectance in the largest radiation of Neotropical songbirds: Implications of accounting for avian vision in the study of plumage evolution

“…To test for changes in plumage conspicuousness with viewing geometry in the Swallow Tanager, we calculated the DS between plumage color and the reflectance spectrum of the canopy of deciduous forest trees obtained from the ASTER spectral library of NASA (http://speclib.jpl.nasa.gov; Baldridge et al 2009) as a representative of a plausible background habitat for this species (Schaefer 1953); thus, the contrast between the color of Swallow Tanagers' plumage patches and the surrounding vegetation as would be perceived by an avian observer served as a proxy of color conspicuousness (Håstad et al 2005). We estimated DS as above using the cone sensitivities of Blue Tits as representative of a UVS type of visual system (such as that of most passerines; Odeen et al 2011), and those of the Red Junglefowl (Gallus gallus; Govardovskii and Zueva 1977, Partridge 1989, Bowmaker et al 1997 as representative of the violetsensitive (VS) type of color vision thought to be typical of falconiiforms (falcons, hawks, and their allies;Ödeen and Håstad 2013, Lind et al 2013, the most likely avian predators of Swallow Tanagers (Schaefer 1953).…”

Ultraviolet vision in lacertid lizards: evidence from retinal structure, eye transmittance, SWS1 visual pigment genes, and behaviour

“…The ability to perceive the ultraviolet (UV) light spectrum, to which humans are blind, is present in most animals with colour vision (Goldsmith, 1994;Pichaud et al, 1999;Briscoe and Chittka, 2001;Ödeen and Håstad, 2013). The ancestral condition of the visual system of vertebrates, which has been retained in many extant taxa, includes a cone photoreceptor whose visual pigment contains the shortwavelength-sensitive type 1 (SWS1) opsin.…”

“…Although considerable progress has been made in the study of the distribution and variability of UV photoreceptors in birds (e.g. Hart and Hunt, 2007;Ödeen et al, 2011;Ödeen et al, 2012;Carvalho et al, 2012;Coyle et al, 2012;Ödeen and Håstad, 2013;van Hazel et al, 2013) and fish (e.g. Carleton et al, 2000;Siebeck and Marshall, 2001;Siebeck and Marshall, 2007;Siebeck et al, 2010), data on other vertebrate linages are relatively scant and encompass few species [e.g.…”

Visual pigments in a palaeognath bird, the emuDromaius novaehollandiae: implications for spectral sensitivity and the origin of ultraviolet vision

“…Black lines indicate UVS pigments, violet lines represent VS pigments, and dotted lines designate the presence of both UVS and VS pigments within the Order. Adapted from [8,9]. rspb.royalsocietypublishing.org Proc.…”