Hidden white and black feather layers enhance plumage coloration in tanagers and other songbirds

Birds are renowned for their diverse and colorful plumage. Here, we demonstrate that vibrant plumage in the tanager genus Tangara is dramatically intensified by a “hidden” layer of achromatic (white or black) plumage concealed beneath the outermost colorful layer. Using hyperspectral imaging, multispectral photography, microspectrophotometry, reflectance spectrophotometry, and optical modeling, we show that hidden white and black feather layers are systematically distributed on the body to enhance the brightness and saturation of carotenoid-pigmented and structurally colored plumage, respectively, by increasing or decreasing the amount of backscattered light that interacts with pigments or nanostructures. We compare male and female coloration and show that sexual dichromatism in some Tangara carotenoid plumage stems primarily from white layers in males and black layers in females rather than from differences in carotenoid pigmentation. Finally, we find that white and..., Datasets in this project include reflectance spectra collected using UV-vis reflectance spectrophotometry, hyperspectral imaging, and microspectrophotometry. Additional datasets include distributions of hue, saturation, and lightness values from regions-of-interest of feathers from multispectral images., , # Hidden white and black feather layers enhance plumage coloration in tanagers and other songbirds

Dataset DOI: [10.5061/dryad.1c59zw46k](10.5061/dryad.1c59zw46k)

## Description of the data and file structure

This dataset contains all data and code to reproduce the Main and Supplementary figures and analyses in Price-Waldman et al. (2025), which demonstrates that hidden layers of achromatic (white or black) plumage are systematically distributed on the body to enhance the color of carotenoid-pigmented and structurally colored plumage in *Tangara* tanagers and other songbirds. Broadly, this dataset contains three types of data: 1) Measurements of color collected with reflectance spectrophotometry, microspectrophotometry (MSP), hyperspectral imaging (HI), and multispectral photography (MP); 2) code and supporting files for optical modeling; and 3) measurements of morphological features of feathers.

Data from MSP, HI, and MP capture the experimental changes in reflectance of the colorf...,