ICP Detail: NW Great Plains

Northwestern Great Plains Region 16*

The Northwestern Great Plains Waterfowl Conservation Region (NGP) is an arid to semi-arid landscape that lies west and south of the PPR, east of the Rocky Mountains, and north of the Southern Great Plains Region. Unlike the PPR, most of the NGP was unglaciated, therefore drainage patterns are well developed. The region is flat to moderately rolling except for the badlands of western North and South Dakota, which feature sharp topographic relief. Outside of riparian areas and shelterbelts, the area is a vast, treeless prairie dominated by vegetation typical of mid-grass and short-grass ecosystems.

Land use in the NGP is predominately devoted to livestock production. In most areas, only 5-15% of the land base has been cultivated, although the rate of cultivation is increasing. New, drought-resistant varieties of soybeans, wheat, and canola are becomingly increasingly common. Shallow aquifers occur under a significant portion of the eastern edge of the region, and there is momentum to use this groundwater, along with Missouri River water stored in mainstem reservoirs, for irrigated agriculture. Profitable, irrigated crops like potatoes and other root vegetables thrive in the soils and cool growing climate of the NGP.

Compared to the PPR, relatively few natural wetlands exist in the NGP. However, numerous manmade wetlands have been created for livestock and wildlife. These created wetlands have resulted in a net increase in wetlands since European settlement. "Stock ponds" are usually small (~1 to 5 ha) wetlands that are created by impounding seasonal streams or runoff from shallow basins. "Dugouts" are excavated wetlands under 1 ha in size that are created to water livestock. Together with natural marshes and wetlands that occur along riparian corridors, stockponds and dugouts provide surprisingly productive habitat for waterfowl. In many parts of the NGP, wetlands densities equal or exceed 1 pond/km2, with an average wetland size of about 1 ha. Nevertheless, the NGP remains a dry environment, and the number of wetlands is believed to limit the abundance of waterfowl in the region.

Waterfowl in the NGP

Although the NGP provides important spring and fall migration habitat for waterfowl, it is most important as a duck production area. The relationships among wetlands, grasslands, predators, and duck nesting success described earlier for the Prairie Pothole Waterfowl Conservation Region also apply to the NGP. The vast, unfragmented grasslands of the region enable ducks to disperse their nests, presumably making them less vulnerable to predators. Moreover, the predator community in the NGP is dominated by coyotes. Red foxes, raccoons and skunks, the important duck predators in the PPR, are far less abundant in the NGP. Consequently, duck nesting success and waterfowl production per wetland area is greater than in the PPR.

Collectively, breeding waterfowl in the NGP are a significant component of the continental population. Brewster et al. (1976) found that the NGP portion of South Dakota accounted for 21% and 31% of the state's breeding duck pairs in 1973 and 1974, respectively. Stewart and Kantrud (1974) suggested that 16% of the breeding ducks in North Dakota in 1967 were in the NGP portion of the state. During 1989-98, the number of breeding ducks in the NGP (derived from the May aerial survey) averaged 21% of the total ducks in the U.S. survey area. In 1990-93, when the PPR was dry, the NGP held a higher proportion of the breeding birds than when the PPR was wet during 1994-98 (Fig. 1). This reinforces the belief that the relatively stable water levels of NGP wetlands provide ducks a refuge during drought.


Figure 1. Breeding duck populations estimates for the Northwestern Great Plains and the U.S. Prairie Pothole Region based on May aerial surveys, 1974-2004. Northeastern Wyoming is not included in the NGP data.

In north central Montana, an area very similar to and just north of the NGP region, Ball et al. (1995) observed 6.9 breeding pairs/km2, or 7.7 pairs/ha of water. However, most waterfowl recruitment studies in the NGP have relied on brood surveys to index recruitment. Lokemoen (1973) found 32 broods/100 wetland ha in western North Dakota, which was less than the 61 broods/100 wetland ha observed on stock ponds by Bue et al. (1952) in western South Dakota. Since 1986, DU biologists have surveyed broods on NGP stock ponds created in cooperation with ranchers, the USFS (National Grasslands), and other partners. DU survey data on 31 wetland creation projects revealed an average of 20 broods/100 wetland ha (range of 0-170), with a mean brood size of 5.5 ducklings. In general, brood densities in the NGP equal or exceed those found in the PPR. Although recruitment rates (number of fledged females per adult female in the spring population) are not known with certainty, Ball et al. (1995) observed 48.1 broods/100 breeding pairs of dabbling ducks, suggesting a hen success rate (percent of hens that successfully hatch at least one egg) of over 48%. This is considerably higher than hen success for mallards in the PPR, and greater than reported broods/pair ratios in the Canadian portion of the PPR (e.g., 10 broods/100 pairs; Hochbaum et al. 1987).

Species composition of breeding ducks is similar to that found in the PPR. Research on DU projects in the NGP region reveals that blue-winged teal were the most common species (28% of broods observed), followed by mallards (22%), gadwall (19%), other or unknown (10%), pintail (8%), wigeon (7%), and shoveler (6%). Canada geese made up <1% of waterfowl observed. Breeding ducks populations in Lokemoen's (1973) study areas in western North Dakota were dominated by mallards (50%), followed by wigeon (15%), pintails (13%), and blue-winged teal (12%).

Other Wetland- and Grassland-Dependent Wildlife

The large, unfragmented grasslands of the NGP provide important habitat for many grassland songbirds, particularly "area-sensitive" species. Baird's sparrows, Sprague's pipits, McCowan's longspurs, and mountain plovers are among the high priority species. Over a dozen different shorebird species have also been observed on created wetlands in the NGP, including Wilson's phalaropes and long-billed curlews.

Conservation Programs in the Northwestern Great Plains Region

The NGP is designated a secondary emphasis area for DU's "Grasslands for Tomorrow" Initiative. Under the umbrella of Grasslands for Tomorrow, DU works with the USFS (National Grasslands), the BLM, the USFWS (Partners for Fish and Wildlife Program), and private landowners to create and enhance wetlands in the region. Most projects are designed to provide waterfowl benefits as well as water for livestock. These projects have been very popular with landowners in the region. Since 1984, DU has completed about 185 such projects in the NGP.

The Northern Great Plains Joint Venture was recently formed which encompasses the entire Northwestern Great Plains Region. The Joint Venture Management Board has only recently been formed and the Technical Committee is currently being assembled. Once up and running, maintaining and protecting existing wetlands and grasslands, as well as creation and enhancement of wetlands will be a major focus for the NGPJV.




* Region 16 -NABCI Bird Conservation Region 17 ( Badlands and Prairies)

Revised January 5, 2005 - Region 16

    Minor updates and corrections