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Impact of the Conservation Reserve Program on Duck
Recruitment in the U.S. Prairie Pothole Region

Ronald E. Reynolds, Terry L. Shaffer, Randy W. Renner,
Wesley E. Newton, and Bruce D. J. Batt

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Abstract: The U.S. Department of Agriculture (USDA)'s Conservation Reserve Program (CRP) resulted in the conversion of about 1.9 million ha of cropland to perennial grass cover in the Prairie Pothole Region of North Dakota, South Dakota, and northeastern Montana by 1992. Many wildlife managers believed this cover would provide benefits to wildlife, including upland nesting ducks. During 1992-1995, we evaluated success of 5 duck species nesting in CRP fields and nearby Waterfowl Production Areas (WPA) throughout the region. We examined relationships between daily survival rates (DSR) of duck nests in CRP cover and landscape-level habitat and population parameters. We computed DSR of duck nests in other major cover types in our study area from data collected during 1980-1984 (pre-CRP) and 1990-1994 (CRP) periods. We then applied recruitment models to estimate duck production in our study area during peak CRP years (1992-1997) and compared these results with those that simulated the scenario in which cropland was in place of CRP cover (i.e., the CRP had not occurred). DSR were higher in all habitats combined during the CRP period compared to the pre-CRP period. Regressions of DSR in CRP cover on the percent of each study plot in perennial cover and geographic location were significant (P < 0.01) for 4 of 5 duck (Anas spp.) species. Estimated nest success and recruitment rates for the 5 species combined during 1992-1997 were 46% and 30% higher, respectively, with CRP cover on the landscape compared to a scenario where we simulated cropland in place of CRP. Our model estimated an additional 12.4 million recruits from our study area to the fall flight as a consequence of the CRP during 1992-1997. Our results document benefits to 5 duck species in the northern plains associated with a farm program that provided financial incentives to landowners for planting undisturbed grass cover as an alternative to annual crops.

Keywords: Anas acuta, Anas clypeata, Anas discors, Anas platyrhynchos, Anas strepera, blue-winged teal, Conservation Reserve Program, CRP, ducks, gadwall, mallard, nest success, northern pintail, northern shoveler, Prairie Pothole Region, recruitment.

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This resource is based on the following source (Northern Prairie Publication 1147):

Reynolds, Ronald E., Terry L. Shaffer, Randy W. Renner, Wesley E. 
     Newton, and Bruce D. J. Batt.  2001.  Impact of the Conservation 
     Reserve Program on duck recruitment in the U.S. prairie pothole 
     region.  Journal of Wildlife Management 65(4):765-780.

This resource should be cited as:

Reynolds, Ronald E., Terry L. Shaffer, Randy W. Renner, Wesley E. 
     Newton, and Bruce D. J. Batt.  2001.  Impact of the Conservation 
     Reserve Program on duck recruitment in the U.S. prairie pothole 
     region.  Journal of Wildlife Management 65(4):765-780.  Jamestown, 
     ND: Northern Prairie Wildlife Research Center Online.  
     http://www.npwrc.usgs.gov/resource/birds/duckrecr/index.htm
     (Version 27AUG2002).

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Table of Contents

• Introduction
• Study Area and Selection of Study Sites
• Methods
  • Habitat Classification and Mapping
  • Wetland Assessment
  • Estimation of Numbers of Breeding Pairs
  • Selection of Plots for Nest Data Collection
  • Predator Indices
  • Field Methods
  • Analytical Procedures
    • Duck Nesting Study
    • Duck Production Models
• Results
  • Breeding Pairs and Wetland Habitat
  • Duck Nesting Study
  • Variables Affecting Daily Survival Rates
  • Model for Estimating Daily Survival Rates in CRP
  • Nesting Habitat Preference and Nest Success
  • Impact of CRP on Duck Production
• Discussion
• Management Implications
• Acknowledgments
• Literature Cited

Tables and Figures

• Table 1 -- Input parameters for duck production models and data sources used in analyses to estimate production for 5 principal duck species.
• Table 2 -- Number of replicates and area of CRP cover and WPA planted cover that were searched for duck nests.
• Table 3 -- Number of usable duck nests found in CPR cover and WPA planted cover in the Prairie Pothole Region.
• Table 4 -- Least squares estimates of daily survival rates of duck nests in CRP and WPA planted cover.
• Table 5 -- Correlation of daily survival rates of nests for 5 species of ducks with breeding population size, numbers of ponds, area wet, percent of landscape in perennial cover, location, and indices to red fox and coyote abundance.
• Table 6 -- Results of stepwise regression models using daily survival rates of duck nests in CRP cover by species as the response variable.
• Table 7 -- Relative preference that 5 species of ducks show for 8 habitats in the Prairie Pothole Region of North Dakota.

• Figure 1 -- Study area for assessing the impact of the Conservation Reserve Program on duck recruitment.
• Figure 2 -- Relationship between daily survival rate of nests and percent total perennial cover for 5 species of ducks.
• Figure 3 -- Geographic variation in daily survival rate and nest success of mallard nests.

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Ronald E. Reynolds, Habitat and Population Evaluation Team Office, U.S. Fish and Wildlife Service, 3425 Miriam Avenue, Bismarck, ND 58501, USA.  E-mail: ron_reynolds@fws.gov
Terry L. Shaffer and Wesley E. Newton, Northern Prairie Wildlife Research Center, U.S. Geological Survey, 8711 37th Street SE, Jamestown, ND 58401, USA.
Randy W. Renner, Great Plains Regional Office, Ducks Unlimited Incorporated, 2424 River Road, Bismarck, ND 58501, USA.
Bruce D. J. Batt, National Headquarters, Ducks Unlimited Incorporated, One Waterfowl Way, Memphis, TN, 38120, USA.

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