Ultraviolet and Visible Light Differences in the Plumage Coloration of Adult Male and Female Florida Scrub-Jays (Aphelocoma coerulescens)

Abstract

To the human eye, sexes of the threatened Florida scrub-jay (Aphelocoma coerulescens) appear identical. Several studies have hinted at the idea that these birds may be able to identify the sex of their conspecifics by detecting subtle differences in plumage coloration within the ultraviolet light spectrum using their advanced vision. However, a figure from a Siefferman et al. paper suggests that differences may actually lie solely in the visible light spectrum. This leads to the questions of do differences exist in the plumage coloration between male and female Florida scrub-jays and, if so, are these differences found in the visible light spectrum, ultraviolet light spectrum, or both? After collecting data at Archbold Biological Center and analyzing visible and ultraviolet light images, no significant distinct differences were found in plumage coloration between the sexes, especially within the ultraviolet light spectrum. Future research can continue to explore differences within the visible light spectrum and should find ways to effectively study this on live specimens.