Bruce D.J. Batt | Search USGS

USGS2001

Impact of the Conservation Reserve Program on duck recruitment in the U.S. Prairie Pothole Region

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.

Journal of Wildlife Management↗

USGS2001

Predation on waterfowl in arctic tundra and prairie breeding areas: A review

Predation is a natural component of waterfowl population biology, but environmental alterations have changed the magnitude and importance of predation on waterfowl breeding areas. We reviewed the status of waterfowl populations, adaptations of waterfowl that minimize impacts of predation, and the impacts of predation on waterfowl populations in 2 major North American breeding areas, the Arctic and Prairie Regions. We identified the underlying factors contributing to most waterfowl predation problems to be changes in essential breeding habitats and changes in predator community composition and abundance. In the Arctic, high predation rates on waterfowl eggs and young are usually associated with predators gaining access to populations that were previously isolated. In the prairie, predation problems are often related to large-scale habitat degradation coupled with changes in predator communities. Predation problems are often symptomatic of inadequate habitat management, but we recognize that habitat management alone is not always sufficient to effectively manage predation problems. Predation management efforts should be integrated with strategies of long-term management of habitats critical to breeding waterfowl, strategies embraced by the North American Waterfowl Management Plan. Predation management must be tailored to different situations and include an element of flexibility that allows appropriate response to the dynamic nature of factors influencing survival and recruitment.

Wildlife Society Bulletin↗