Mallard x black hybrids are the only hybrid waterfowl we are NOT seeking for this study. They are less useful for this study because their interbreeding resembles a traditional contact zone between species than hybridize extensively where their ranges come into contact. Because mallard x black hybrids are so abundant, and because they are found at a range contact, this situation is quite unlike the occasional hybrids that are reported throughout areas of range overlap between other waterfowl species pairs. Further, mallard x black hybrids breed so successfully that hybrids we would receive would not be F1s, and it is F1 hybrids that offer the strongest tests of the three specific hypotheses that may explain the origin of hybrid waterfowl . Finally, if we need. we will be able to have a preliminary look at mallard x black hybrids using specimens from the USFWS wing bees, because many mallard x black hybrid wings are submitted from the Atlantic flyway, and we will have access to these wings.