Gull plumages are, and are not, what they appear to human vision

Authors

Muir D. Eaton, Drake University
Pilar Benites, Universidad Nacional Autónoma de México
Luke Campillo, University of Hawai’i – Mānoa
Robert E. Wilson, Smithsonian Institution, University of Nebraska-LincolnFollow
Sarah A. Sonsthagen, Alaska Science Center, University of Nebraska-Lincoln, Smithsonian InstitutionFollow

Date of this Version

6-20-2022

Citation

Eaton, M. D., Benites, P., Campillo, L., Wilson, R. E. & Sonsthagen, S. A. 2022: Gull plumages are, and are not, what they appear to human vision. — Ann. Zool. Fennici 59: 187–203.

Comments

Used by permission.

Abstract

Clear correlations between human and bird visual assessments of color have been documented, and are often assumed, despite fundamental differences in human and avian visual physiology and morphology. Analyses of plumage colors with avian perceptual models have shown widespread hidden inter-sexual and inter-specific color variation among passerines perceived as monochromatic to humans, highlighting the uncertainty of human vision to predict potentially relevant variation in color. Herein, we use reflectance data from 13 Larus gull species as an exemplar data set to study concordance between human vision and avian visual modeling of feather colors near, or below, the human threshold for discrimination. We found little evidence among gulls for sexual dichromatism hidden from human vision, but did find inter-specific color variation among gulls that is not seen by humans. Neither of these results were predictable a priori, and we reassert that reflectance measurements of actual feather colors, analyzed with avian relevant visual models, represent best practice when studying bird coloration.