Responding to Declining Populations
When populations of ducks and geese
fall persistently below historical levels, DU conducts research to indentify the causes of these declines and develops conservation strategies to reverse the trend. Continentally, northern pintail
and lesser scaup populations are both substantially below their long-term averages. Accordingly, DU has launched investigations into the potential causes driving declines of both species.
research has focused on boreal landscapes, where the decline of this species appears to have been most severe. In contrast, studies of pintails have focused on the prairies—especially in southern Canada—where these birds have suffered their greatest declines. Pintails, more than any other prairie-nesting ducks, are inclined to choose croplands as nesting habitat. Early analyses suggested that this penchant for nesting in cropland, combined with the modernization of agricultural machinery, which has allowed farmers to work fields earlier in the breeding season than in the past, has resulted in a high proportion of pintail nests being destroyed during normal farming activities.
Once a leading hypothesis for the cause of the pintail decline was identified, DU developed a strategy for the bird's recovery guided by the latest scientific research. Most of the pintail production on the prairies occurs on private lands, and cereal grain production is a primary source of income for many of the region's landowners. Consequently, DU sought a solution that would provide improved habitat for pintails while also allowing landowners to continue to make a living by farming the land.
Winter wheat potentially offers a partial solution. Planted in the fall, winter wheat is tilled less frequently in the spring, when ducks—especially pintails—are nesting. Harvest also occurs after most pintail nests have hatched, so including winter wheat in crop rotations in areas where pintails are abundant nesters provides a promising alternative to spring-seeded cereals. Unfortunately, at the outset, winter wheat in the PPR had some serious agronomic challenges. Early varieties were susceptible to both winter kill and disease. Farmers were understandably leery of including winter wheat as a primary component of their farming enterprises. Not to be deterred, DU partnered with
Dr. Brian Fowler, a prominent plant breeder at the University of Saskatchewan, to develop winter-hardy and disease-resistant strains of winter wheat that could thrive in the harsh prairie environment. Today, the number of winter wheat acres planted annually throughout the PPR is increasing, and most of the varieties being planted stem from Dr. Fowler's lab.
Importantly, early research indicates that ducks hatch approximately 12 times more nests per acre in winter wheat than they do in spring-seeded cereals planted nearby. Evaluations of winter wheat continue on both sides of the border as we fine-tune where this crop is likely to be most beneficial to nesting ducks. And in 2011 and 2012, DU scientists from the United States and Canada will be partnering to study duckling survival on study sites in Saskatchewan and North Dakota to ensure that more nests hatched in winter wheat also means more ducks in the sky.
Encouragingly, pintail numbers have been on the upswing in recent years. In 2010, an estimated 3.5 million breeding pintails were present in the traditional survey area—the largest population since 1997 and near a 30-year high. This allowed the U.S. Fish and Wildlife Service to liberalize the daily bag limit on pintails to two birds in every flyway.
Ducks Unlimited has always delivered conservation guided by the best available scientific information. By continuing to invest in science, DU is positioning itself to continually improve its conservation programs—evaluating the key assumptions underlying its conservation actions and adapting its programs with new information. The end result is increasing returns on DU's conservation investments and more ducks in North America's skies.
Dr. David Howerter is national manager of the Institute for Wetland and Waterfowl Research at DU Canada headquarters at Oak Hammock Marsh. Johann Walker is manager of conservation programs at DU's Great Plains office in Bismarck, North Dakota.