Anas diazi

The Mexican duck (Anas diazi, and see below) is a dabbling duck in the genus Anas which breeds in Mexico and the southern United States. Most of the population is resident, but some northern birds migrate south to Mexico in winter. It is a bird of most wetlands, including ponds and rivers, and usually feeds by dabbling for plant food or grazing. It nests usually on a river bank, but not always particularly near water. Mexican ducks are fond of the green shoots of alfafa and feed at night on irrigated fields. Both sexes of this 51–56 cm length bird resemble a female mallard, but with a slightly darker body. The Mexican duck is mainly brown, with a blue speculum edged with white, obvious in flight or at rest. The male has a brighter yellow bill than the female.