One of the more nondescript of the Anas ducks, the male Gadwall can be distinguished by its gray overall plumage and black rump. Both sexes have a distinctive white speculum, which is unique to the species. They can be found in both salt and freshwater; however, during the winter when they are found in Mexico and the Caribbean, they are quite common in coastal habitats. Like other dabbling ducks, the Gadwall feeds on aquatic vegetation from the surface of the water by head-dipping and upending; it also will graze from land. Clutch sizes are relatively large and can number up to 12 eggs or more. However, some of these eggs might not have been laid by the incubating female because some Gadwall females implement conspecific egg-dumping as a breeding strategy. A very abundant duck in the Americas; new world populations have been recently estimated between one-and-a-half and two million individuals.