Understanding Waterfowl: Fair-Weather Friends

By Scott Stephens, PhD; Nathan Ratchford; and Mike Brasher, PhD

Over the past couple of decades, blue-winged teal have been among North America’s most abundant dabbling ducks, with a peak breeding population estimate of 9.2 million in the traditional survey area in 2012. In recent years, however, blue-winged teal numbers have fallen along with many other dabblers, as drought has gripped the Prairie Pothole Region. In 2024, the bluewing population dipped to 4.6 million—the lowest estimate since 2005. Biologists expect the population to rebound when the prairies recover from drought, but sustained efforts to conserve key waterfowl habitats will be essential to ensure that bluewings and other ducks continue to bounce back when wet weather returns.

Blue-winged teal are unique among dabbling ducks in that they spend the least amount of time on the breeding grounds each year. Pairs of blue-winged teal arrive on the prairies and other breeding areas in early May, when many mallards and northern pintails are already nesting. To acquire nutrient reserves for egg production, female bluewings feed heavily on aquatic invertebrates in shallow wetlands. Once they have acquired those nutrients, hens begin nesting, typically in short grass near wetlands with ample food resources. Hens lay an average of 10 to 12 eggs (at a rate of one egg each day) in a simple nest bowl scraped into the ground. Many bluewing nests have a “tent” of grass over the top, which provides cover for the nesting female and her eggs.

Female bluewings tend to hold very tight on their nests when predators approach. Scientists believe this strategy could reduce the odds of predators detecting hens and their nests, and this might be one reason why blue-winged teal seem to have higher nest success on average than that of many other dabblers. If nests are lost to predation, hens will renest once or twice to successfully produce a brood.

Shortly after the ducklings hatch, hens lead their broods to nearby shallow wetlands, where they feed on invertebrates. During the brood-rearing period, hens and ducklings spend much of their time in flooded emergent vegetation such as cattails or bulrushes to escape detection and predation. Juvenile bluewings are able to fly 40 to 45 days after hatching.

The most pressing threat to maintaining healthy populations of blue-winged teal and many other duck species is the conversion of wetlands and associated grasslands in key breeding areas. Protecting these habitats through perpetual conservation easements or shorter-term agreements and maintaining agricultural policies that discourage the drainage and conversion of wetlands and grasslands are vital to the future of prairie-nesting ducks, including blue-winged teal.

Bluewings are among the first ducks to leave northern breeding areas in late summer and early fall. Many of these birds—especially mature drakes and nonbreeding hens—depart the prairies by late August and early September. Unlike more cold-tolerant species, they avoid colder weather by moving quickly to warmer regions. Diet is perhaps the most important factor shaping their unique migration habits. Although bluewings do eat a variety of plant seeds and submerged aquatic vegetation, their diet is largely composed of small insects found in shallow wetlands. These wetlands are among the first to freeze in the fall, putting bluewings at risk of losing access to essential food resources. Because of this disproportionate reliance on shallow wetlands, their distribution during fall and winter closely matches the availability of open water. As a result, where you find bluewings during fall migration often changes from year to year.

The migration routes followed by blue-winged teal span vast distances. Many birds travel from breeding areas on the prairies to wintering grounds as far south as Peru and northeastern Brazil. Banding and satellite telemetry studies show that these ducks follow well-established routes, with major migration corridors through the Central and Mississippi Flyways. However, their migratory journeys are more direct and less dependent on traditional stopover locations compared to those of other dabbling duck species. Migration distances vary widely among individual birds, but many travel over 4,000 miles between breeding and wintering areas. Some complete the journey in a matter of weeks, covering hundreds of miles per day when conditions are ideal.

The Gulf Coast is a vital wintering area for blue-winged teal, offering expansive wetlands that support their habitat needs. In the United States, the highest winter densities are found in coastal portions of Texas, Louisiana, and peninsular Florida. These areas are less likely to freeze during winter and also offer an immense diversity of wetland types, including mangrove swamps, fresh and brackish marshes, and flooded agricultural lands, all of which are ideal habitat for bluewings.

While blue-winged teal are abundant along the US Gulf Coast in winter, nearly 80 percent of the continental population winters in Mexico, Central America, the Caribbean, and northern portions of South America. Of these tropical destinations, Mexico is without question the most important, emphasizing the essential nature of Ducks Unlimited’s cross-border conservation work. DU Inc. continues to work closely with Ducks Unlimited Canada and Ducks Unlimited de México to ensure that blue-winged teal and other waterfowl have optimal habitat throughout their annual cycle, from their northern breeding grounds to their wintering areas far to the south.

Changes Coming to Early Teal Regulations

Blue-winged teal are among several species for which a “special” hunting season provides additional harvest opportunity. The first experimental early teal seasons were established from 1965 to 1967 in the Mississippi and Central Flyways and ran for nine consecutive days in September. Changes to early teal regulations have been implemented in subsequent years, including a suspension of the season in the late 1980s and early 1990s, when blue-winged teal populations fell below management objectives. US Fish and Wildlife Service guidelines adopted in 2014 allow for a 16-day early teal season in the Central, Mississippi, and Atlantic Flyways when the breeding population is above 4.7 million birds, and a nine-day season when the estimate is between 3.3 and 4.7 million birds.

In 2025, early teal hunters will want to double-check the regulations, because important changes are on the way. In 2024, the breeding population estimate of 4.6 million birds dipped below the 4.7 million threshold for the first time since 2005 and only the fourth time since 1998. Based on current harvest guidelines, states in the Central, Mississippi, and Atlantic Flyways will be limited to a nine-day September teal season in 2025. Northern states that don’t opt for a special teal season can add two bonus blue-winged teal to the daily limit during the first nine days of the regular duck season.

Dr. Scott Stephens is DU’s senior director of prairie and Boreal conservation strategy. Nathan Ratchford is a conservation communications coordinator and Dr. Mike Brasher is the senior waterfowl scientist at DU national headquarters in Memphis.