USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Factors Limiting Mallard Brood Survival
in Prairie Pothole Landscapes

Management Implications


Waterfowl managers can use our final fitted model as a tool for predicting mallard brood survival in the PPR. Using tables available from the authors or at http://www.npwrc.usgs.gov/resource/broodsrv/broodsrv.htm, managers can obtain predicted brood survival rates and associated standard errors for various levels of WETSEAS, HATCHDATE, and RAIN. The WETSEAS can be estimated or indexed through use of satellite imagery, videography taken from aircraft (Strong and Cowardin 1995), or ground surveys. Brood survival predictors identified in this paper also are being incorporated into a mallard productivity model (Johnson et al. 1987) to improve reliability of mallard recruitment estimates.

The positive relation between WETSEAS and mallard brood survival underscores the need to conserve seasonal wetlands, or where drained, restore seasonally flooded water regimes as a major component of wetland complexes managed for dabbling duck production. Higher survival of early hatched broods suggests management efforts be directed toward improving success of early nests where feasible. Managers may achieve higher nest success by maintaining a high proportion of landscape in perennial cover (Greenwood et al. 1995) through permanent grassland easements, CRP, and other methods. Where adequate perennial cover cannot be maintained, managers may improve nest success by reducing predator numbers (Duebbert and Kantrud 1974), using artificial nesting structures (Doty 1979), or constructing fences (Cowardin et al. 1998) or nesting islands (Giroux 1981) to exclude predators from nesting areas. Management actions that have short-term effects on nesting cover (e.g., spring burning, summer haying) and nest success (e.g., predator removal, maintenance of exclosures) impact recruitment on an absolute basis much more in years when seasonal ponds are plentiful and brood survival is high. We therefore recommend that managers attempt to schedule activities with potentially deleterious, short-term effects on nesting success, such as burning and haying, until after nesting is completed in years when a high proportion of seasonal wetlands contain water.


Previous Section -- Discussion
Return to Contents
Next Section -- Acknowledgments

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/birds/brdland/manage.htm
Page Contact Information: Webmaster
Page Last Modified: Friday, 01-Feb-2013 18:14:48 EST
Sioux Falls, SD [sdww55]