Plumage as a Measure of Quality in Eastern Bluebirds

Abstract

The males of many animal species use bright colors and ornaments to attract potential mates. In this paper I examined studies of how plumage color in eastern bluebirds (Sialia sialis) affects mate choice. I compared findings on this species with findings on European starlings, zebra finches, and blue grosbeaks to identify which visual cues are commonly used by songbirds to identify possible mates. I found that plumage color in all four of these species was linked to individual health, offspring quality, and reproductive fitness . Two ideas that remain unknown are exactly how these visual cues evolve, and how birds learn to assess potential mates.