Tale of Two Teals
Blue-winged and green-winged are colorful native Illinois ducks with similar and differing behaviors

When a blue-winged teal takes flight over an Illinois wetland, you immediately understand how it got its name. The powdery blue patch on its wings is prominent especially when the sun is shining. In flight, the slightly smaller green-winged teal also shows a colorful wing—one that’s green and black in the speculum. Those wing patches are great identification factors in both the male and female of these two native Illinois ducks. Another good identification factor for the green-winged teal is the green patch that adorns the males’ rust-colored head. Females of both teal species are mottled brown to gray, but do show the speculum color.

During migration you’ll spot a group of blue-winged or green-winged teal flying in small, tight formations, turning and landing together with the precision of the Blue Angels. Green-winged teal have been clocked as flying 50 to 60 miles per hour as they deftly twist and turn.

Teal are exciting ducks for bird watchers to observe, and they are among the top five duck species bagged by hunters in Illinois.

Blue-winged teal is a favored duck species for Douglas McClain, Wetland Wildlife Program Manager for the Illinois Department of Natural Resources (IDNR).

“They are really fun to watch,” he explained. They fly so fast, and they’re a very pretty bird, especially in spring.”

These two teal are dabbling ducks, as opposed to divers. Dabbling ducks sit high on the water and skim the surface for a meal. They tip their heads underwater and point their bottoms straight to the sky as they feast on various plants and insects. Diving ducks, including scaup, canvasback, bufflehead and more, spend time in deeper water searching for vegetation and other aquatic creatures.

With their feet centered below their body, dabblers can easily walk on land. Divers, however, have legs at the back of the body, which helps them propel through deep waters, but makes it difficult to walk on land.

Like other dabbling ducks, teals begin pair bonding in fall and winter, and their antics can be observed while they’re resting and feeding on shallow bodies of water during migration in Illinois. The male typically gives a whistle, lifts his rear out of the water, shakes his bill and moves his head up and down to court a mate and ward off other males. It’s a behavior that easily can be observed by even a beginning birder.

Though both species are named teal, they differ in several ways, including their migratory patterns and nesting habitat. In fact, once considered closely related, these two teal species recently have been placed in separate genera. The blue-winged teal, once included in the Anas genus like green-winged teal, has now been placed in the Spatula genus. The Spatula genus includes the northern shoveler, known for its enormous bill that resembles a shovel.

“The bill structure between green-winged and blue-winged teal is very different,” McClain said. “Green-winged teal have a narrow bill, but the blue-winged bill almost looks disproportionately large compared with the rest of its body.”

“Blue winged teal are one of the classic prairie pothole nesting species,” McClain continued. “They raise their broods on small or semi-permanent wetlands in grasslands. Blue-wings really like exposed mudflats and shallow water where there’s less emergent vegetation.” Some migratory blue-winged teal remain in Illinois to breed in the summer when they can find appropriate habitat, for example, a wetland and forested preserve in northern Illinois. The species also nests in Wisconsin, Minnesota and Michigan.

“Green-winged teal nest all the way up into Canada across the boreal forest,” McClain said. “You don’t find them very much on the prairies. Rarely are they found in Illinois in the summer.”

He continued, saying “Green-wings often hang out with northern pintails. They feed in similar habitats, shallow water with plants that produce a lot of seeds that they eat.”

Though the green-winged teal is the smallest duck in North America it’s generally more hardy than the blue-winged teal. Blue-winged teal are among the last to return to the breeding grounds and first to head for warmer climes in fall.

The green-winged teal is one of the first migrant ducks to arrive in spring, often in late February, well ahead of the blue-winged teal. Once the blue-winged teal shows up, sometime in April or later farther north, you know duck migration is coming to an end.

Blue-winged teal are already heading south in September after the breeding season, with fewer numbers being seen in Illinois by October. Green-winged teal numbers peak, sometimes into the tens of thousands, in November and December.

“In some of our mid-November surveys last fall we had between 40,000 and 60,000 at one time on Chautauqua National Wildlife Refuge, located on the east side of the Illinois River in Mason County,” McClain said.

Green-wings and blue-wings winter on the gulf coast, but some blue-wings go as far south as Central America and South America after breeding.

Both teal species rank in the top five species harvested by hunters in Illinois and both species are doing well in North America, according to McClain. Roughly 5.3 million blue-winged teal and 2.5 million green winged teal breed in North America, according to recent estimates. To be sure, many more blue-winged teal nested in Illinois before wetlands were disturbed for agriculture and development.

Recent IDNR-supported research at the Forbes Biological Station has begun on green-winged teal to evaluate dabbling duck movements in relation to hunting pressure.

McClain said those kinds of studies enable waterfowl managers to determine, among other decisions, how many rest days may be ideal during the hunting season at various public hunting sites.

“The best places to spot teal in Illinois are in wetland habitat along the Illinois River Valley,” McClain said. “The Emiquon Nature Preserve and Chautauqua National Wildlife Refuge are great spots. Farther south, you can find them near the confluence of the Illinois and Mississippi rivers.”

Look for green-winged teal gatherings especially in March and November. Higher numbers of blue-winged teal migrants are more often found in April and September.

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Sheryl DeVore writes environment and nature pieces for regional and national publications and has had several books published, including “Birds of Illinois” co-authored with her husband, Steven D. Bailey.