Summary

Description

Nest density and nest success of ducks in native and nonnative grasslands within the Devils Lake WMD, Northeastern North Dakota. Waterfowl representing 8 species of prairie nesting ducks were systematically surveyed from lateApril thru late August, 2010 2013 to compare nest density, nest success and vegetative structure used by nesting ducks in either native restoration sites or nonnative planted vegetation commonly known as dense nesting cover DNC. We located 4,286 waterfowl nests over 4 breeding seasons. Nest densities in native restored uplands averaged 1.13 .48 nests per acre compared with 1.41 .12 for DNC. These results indicated that sampled nest densities were not equal .25 P .50 within these 2 cover types. Nest densities for 5 species of prairie nesting puddle ducks showed that they did not nest evenly across both habitat types examined .10 P .25. Average Mayfield nest success equaled 38 18 for natives compared to 48 10 for DNC; Mayfield results in either cover type over the 4 year study period is well above the minimal nest success of 15 needed to maintain prairie nesting waterfowl across northeast North Dakota. However, late season nest success in 2011 was lower than 15 in native restored uplands suggesting that perhaps predators, nest cover, prior years management, field location or all combined factors may contribute to explain the poor performance during that particular year. Nest success results for 2010, 2012 and 2013 indicated a more normalized and consistent nest success result within native vegetation; nest success remained very consistent in DNC sites throughout the 4 years of investigations. Finally, habitat structure at waterfowl nest sites differed, vegetation height and visual obstruction were significantly lower .10 p .05 in Native habitat versus DNC, litter depth was not significantly different in either field type. Performance within either native or nonnative cover type indicated that both restoration techniques used to restore upland habitats works well for prairie nesting ducks, but DNC has higher productivity both from a nest density and nest success perspective, especially for mallard and gadwall. However, plant species richness typified by native restoration sites may provide a more resilient habitat type especially in the face of more frequent climatic oscillations, and may provide more niches and more habitat structural diversity for a greater diversity of wildlife species. Published data suggests that nonnative grassland restorations lack resilience in the face of severe drought, and may be prone to accelerated invasion by noxious weeds and other nonnative invasive species. Also, Native upland restoration techniques may play a more pivotal role towards diversifying prairie landscapes in the long term as DNC is a much shorter lived habitat type. Native habitat restoration methods have proven to be adequate for producing adequate nest cover for prairie nesting ducks. A more diversified and resilient landscape is argued by climate scientists as one critical activity needed to retard impending climate change, this study provides a baseline effort showing that localized waterfowl production objectives can be achieved with native vegetation while potentially addressing a larger ecological question.