Eider Duck Brood (IMAGE) University of Chicago Press Journals Caption Waterfowl are "careful, sophisticated bargainers," negotiating not only how much effort each puts into communal rearing of ducklings, but also profit-sharing, says a new study from the American Naturalist. Credit Courtesy Nils Sundberg Usage Restrictions None License Licensed 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.