High levels of reflectivity and pointillist structural color in fish, cephalopods, and beetles

Roberts, Nicholas W.; Marshall, N. Justin; Cronin, Thomas W.

doi:10.1073/pnas.1216282109

Cited by 9 publications

(8 citation statements)

References 5 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Structural coloration is widespread in nature and can be observed in butterflies (10,26), beetles (27)(28)(29)(30), fruits (31,32), as well as fish (33,34). Obviously, the control of the color of the reflected light as well as of the directional distribution is likely to be a behaviorally linked, key characteristic of many iridescent animals (35,36).…”

Section: Discussionmentioning

confidence: 99%

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

Wilts

Michielsen²,

Raedt

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

109

121

View full text Add to dashboard Cite

Birds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced by melanin rodlets arranged in layers, together acting as interference reflectors. Light reflection by the silvery colored occipital feathers is unidirectional as in a classical multilayer, but the reflection by the richly colored breast feathers is threedirectional and extraordinarily complex. Here we show that the reflection properties of both feather types can be quantitatively explained by finite-difference time-domain modeling using realistic feather anatomies and experimentally determined refractive index dispersion values of keratin and melanin. The results elucidate the interplay between avian coloration and vision and indicate tuning of the mating displays to the spectral properties of the avian visual system. biophotonics | body colors | courtship | signaling | reflectance B irds-of-paradise are best known for their magnificent coloration. 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 (1-4). 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. The females on the other hand have dull brownish plumage which has remained in its ancestral color state (1, 2).Whereas the biological purpose of the colorful displays is relatively well understood (1, 2), the coloration mechanisms of the birds' displays and the connection to the visual system of the animals are poorly explored. Feather coloration can be generally categorized in two forms: pigmentary and structural. Randomly arranged, inhomogeneous media containing pigments are colored, because the pigments absorb the diffusely scattered light in a restricted wavelength range. For instance, carotenoids cause the colorful yellow or red feathers of many songbirds (5), and the ubiquitous, broad-band absorbing pigment melanin causes feathers to be black (6). Structural colors occur in feather barbs due to quasiordered spongy structures, and in feather barbules due to melanosomes--nanosized, melanin-containing granules--regularly arranged in layers within a keratin matrix, resulting in directional reflections because of constructive interference (7-11). Differences in the morphology of the structural colored feathers, i.e., in the dimensions of the spongy structured barbs or the melanosome multilayers in the barbules, can modify the color of the ...

show abstract

Section: Discussionmentioning

confidence: 99%

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

Wilts

Michielsen²,

Raedt

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

109

121

View full text Add to dashboard Cite

show abstract

“…Changes to the pitch (helix repeat distance) can move the wavelength of maximum reflection, and a distribution in the pitch can create a broadband reflector [ 26 ]. Moreover, spatial variation in the pitch and the creation of a pointillist surface manipulates the spectral signature in the eyes (and visual acuity) of the intended receiver [ 27 – 29 ].…”

Section: Introductionmentioning

confidence: 99%

Selection of the intrinsic polarization properties of animal optical materials creates enhanced structural reflectivity and camouflage

Feller

Jordan

Wilby

et al. 2017

Phil. Trans. R. Soc. B

Self Cite

View full text Add to dashboard Cite

Many animals use structural coloration to create bright and conspicuous visual signals. Selection of the size and shape of the optical structures animals use defines both the colour and intensity of the light reflected. The material used to create these reflectors is also important; however, animals are restricted to a limited number of materials: commonly chitin, guanine and the protein, reflectin. In this work we highlight that a particular set of material properties can also be under selection in order to increase the optical functionality of structural reflectors. Specifically, polarization properties, such as birefringence (the difference between the refractive indices of a material) and chirality (which relates to molecular asymmetry) are both under selection to create enhanced structural reflectivity. We demonstrate that the structural coloration of the gold beetle Chrysina resplendens and silvery reflective sides of the Atlantic herring, Clupea harengus are two examples of this phenomenon. Importantly, these polarization properties are not selected to control the polarization of the reflected light as a source of visual information per se. Instead, by creating higher levels of reflectivity than are otherwise possible, such internal polarization properties improve intensity-matching camouflage.This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.

show abstract

“…Phylogenetic independent contrasts analysis indicates the microstructures of butterfly wings may have evolved in part to regulate mid-infrared emissivity as an adaptation to climate, rather than as phylogenetic inertia. Our findings offer new insights into the role of microstructures in thermoregulation and suggest both evolutionary and physical constraints to butterflies' abilities to adapt to climate change.Scientists and engineers have long been fascinated by the dazzling array of optical properties present in nature [1][2][3][4][5][6][7][8][9][10][11][12][13] . While coloration is a tangible reminder of the wonders of microstructures in animals, microstructures may also play a significant role in thermoregulation.…”

mentioning

confidence: 99%

“…Scientists and engineers have long been fascinated by the dazzling array of optical properties present in nature [1][2][3][4][5][6][7][8][9][10][11][12][13] . While coloration is a tangible reminder of the wonders of microstructures in animals, microstructures may also play a significant role in thermoregulation.…”

mentioning

confidence: 99%

Air temperature drives the evolution of mid-infrared optical properties of butterfly wings

Krishna

Nie

Briscoe

et al. 2021

Sci Rep

View full text Add to dashboard Cite

This study uncovers a correlation between the mid-infrared emissivity of butterfly wings and the average air temperature of their habitats across the world. Butterflies from cooler climates have a lower mid-infrared emissivity, which limits heat losses to surroundings, and butterflies from warmer climates have a higher mid-infrared emissivity, which enhances radiative cooling. The mid-infrared emissivity showed no correlation with other investigated climatic factors. Phylogenetic independent contrasts analysis indicates the microstructures of butterfly wings may have evolved in part to regulate mid-infrared emissivity as an adaptation to climate, rather than as phylogenetic inertia. Our findings offer new insights into the role of microstructures in thermoregulation and suggest both evolutionary and physical constraints to butterflies’ abilities to adapt to climate change.

show abstract

High levels of reflectivity and pointillist structural color in fish, cephalopods, and beetles

Cited by 9 publications

References 5 publications

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

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

Selection of the intrinsic polarization properties of animal optical materials creates enhanced structural reflectivity and camouflage

Air temperature drives the evolution of mid-infrared optical properties of butterfly wings

Contact Info

Product

Resources

About