Plumage comparisons (IMAGE) University of Washington Caption Illustrations of the muted plumage typical of most adult female white-necked jacobin hummingbirds, shown on the left, and the blue-and-white plumage of all males and approximately 20% of adult females, on the right. Credit Jillian Ditner Usage Restrictions Must include credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.