By Scott Stephens, Ph.D.
Following one hen throughout its annual cycle reveals much about the key habitat challenges facing waterfowl
The rising sun peeks over the rolling hills of North Dakota’s Missouri Coteau, gradually warming the broad prairie landscape after a cool April night. A tawny hen pintail dabbles for aquatic insects in a shallow wetland recently filled by melting snow, while her handsomely plumed mate stands guard. Soon she will choose a nest site in the surrounding uplands and lay her clutch of eight olive-colored eggs.
Fortunately for this hen, the productive wetlands that have attracted her to breed in this area of Kidder County just north of Lake Josephine are situated in a landscape dominated by grassland. Through extensive research conducted on the prairies of the United States and Canada, we have learned that ducks nesting in landscapes dominated by grassland achieve high nest success. In many areas of the Missouri Coteau in the Dakotas, duck nesting success in grassland-dominated areas can exceed 40 percent, likely similar to that of pre-settlement times. DU’s research has also shown that poor duck nesting success inevitably occurs in places where the habitat base has been degraded and reduced. These results illustrate that duck production is largely determined by the quantity and quality of habitat available for breeding birds.
The good news is there are still many areas across the prairies where grassland dominates the landscape. The bad news is economic forces are now encouraging widespread conversion of prairie grassland for other uses. Demand for ethanol has dramatically increased corn prices, which has increased the demand for cropland in general and pushed up prices for other crops as well. For example, the price of wheat, the number one crop in the Prairie Pothole Region (PPR), has soared to a record $20 a bushel this spring. High commodity prices and increased demand for cropland can come at the expense of existing grassland that is vital to breeding ducks. In 2007 alone, nearly 49,000 acres of native grassland were converted to cropland across the U.S. portion of the PPR. In addition, contracts expired last year on nearly 850,000 acres of restored grassland on Conservation Reserve Program (CRP) lands in North Dakota, South Dakota, and Montana, and most of this habitat was converted back to cropland last fall.
DU and its conservation partners are focused on saving critical grasslands and wetlands on the prairies, and many landowners in the Dakotas are interested in doing the same. Currently, more than 900 landowners have offered to protect more than 412,000 acres of important waterfowl habitat with grassland easements. Unfortunately, the demand for these easements far exceeds available funding. DU is also working closely with policymakers in Washington, D.C., to ensure that rental rates for CRP are competitive with cropland rental rates. In addition, DU has been a leading advocate of a Sodsaver provision in the next Farm Bill that would make newly converted grassland ineligible for crop insurance and disaster payments.
After incubating her eggs for just over three weeks, our hen successfully hatches her brood during the third week of May. Nearby seasonal wetlands contain the perfect combination of food and cover for the hen and her ducklings. Over the next several weeks, the birds move to several different wetlands to find the invertebrates needed to nourish the ducklings’ growth and the hen’s molt.
By early July, six surviving ducklings are able to fly, and our hen is finished with her parental duties. The young birds now make daily flights in search of food to build fat reserves prior to the fall migration. In early August, our hen has replaced her flight feathers following the molt and flies east into the more intensively farmed drift plain of North Dakota, where recently harvested wheat and barley fields offer abundant waste grain and summer thunderstorms have replenished wetland habitats.
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