Aix sponsa, also known as the Carolina Duck. They breed in wooded swamps, lakes, marshes or ponds in eastern North America, west U.S. and western Mexico. The females will lay 9 to 14 eggs, but if nesting boxes are too close together, they might lay their eggs in the nests of neighbors, causing as many as 40 eggs to gather in a nest, which can not be properly incubated.