The smallest known dabbling duck, the green-winged teal is a North American water fowl named for the bright green patch on the male's wings. Normally found in Canada and the northern United States during breeding season, this duck can be seen throughout North America during migration. The scientific name for the green-winged teal is Anas crecca.
The green-winged teal is generally between 12.2–15.4 inches (31–39 cm) long, with a maximum wingspan of about 23 inches (59 cm). Nonbreeding males, juveniles, and females all have a mottled gray or brown coloring. A breeding male, however, has a rust colored head with a thick green stripe covering each eye and curving down toward its neck. Although it has a patch of green on each wing, the majority of its wings and body are mostly gray, with a mottled brown and black chest. A vertical stripe runs down each side of its body near its wings, and it is this stripe that distinguishes the North American population from the Eurasian teal, which has a white stripe running down its back instead.
Living in marshes and near lakes and ponds, these ducks primarily eat local vegetation, as well as various invertebrates such as aquatic insects, tadpoles, and crustaceans. Their diets change depending on the availability of specific food sources during a particular season. A dabbler, the green-winged teal will dip its beak or head into the water in search of food, sometimes tipping its entire body vertically in order to reach its food source.
Although the green-winged teal can be found throughout the United States during migration, during breeding season they are found primarily in Alaska, Canada, and the Northwestern to north Midwestern areas of the US. They generally breed during summer months, spending the winter farther south. Some of these ducks winter as far south as Central America. Despite a strong population decline in the mid-1900s, the green-winged teal has since recovered its numbers. In 2009, the estimated population of this species was 3.4 million.
Pair bonds are only formed during mating season and are dissolved during the incubation period. Females build nests on the ground near a water source and under the cover of vegetation. Nests are shallow holes that are lined with grasses and down. After mating occurs, the female green-winged teal will lay an average of eight or nine eggs and have sole incubation responsibility for about three weeks. The ducklings are mobile mere hours after hatching and will fledge approximately one month later.