Abstracts

Presented by David A. Brandt - Email: dbrandt@usgs.gov

The Prairie Pothole Region of the Dakotas is arguably the most important area for waterfowl production in the U.S. and includes two general physiographic regions that vary greatly in wetland and landscape characteristics. The Glaciated Plains located in the eastern third of the states is characterized by a land base devoted predominantly to crop agriculture with some remaining intact grasslands used for haying and grazing. Coteau regions west of the Glaciated Plains (Missouri Coteau) and in northeastern South Dakota (Prairie Coteau), vary more in magnitude of cropping intensity but generally have more perennial cover and intact grasslands with a slightly higher density of wetland basins. We hypothesized that given the different characteristics of these landscapes, factors which affect nest, brood, and duckling survival could also differ and may ultimately be reflected in characteristics of broods. We conducted brood surveys across Glaciated Plain and Coteau landscapes 19941998 to assess differences that may exist in broods originating from these areas. Size of broods older than 25 days did not vary between regions but average date of hatching varied by 3-9 days depending on species. We will discuss possible mechanisms responsible for differences and broader implications from a population standpoint as agriculture continues to intensify in this region.