Presentation Abstract

Title: Modeling scaup populations across seasons and regions: application for a comprehensive conservation action plan.
Session Title: Multi-scale Modeling for Conservation of Migratory Birds
Session Number: 63
Session Time: Tuesday, Oct 16, 2012, 1:30 PM - 5:20 PM
Presentation Time: Tuesday, Oct 16, 2012, 2:30 PM - 2:50 PM
Presentation Number: 3
Author(s): Jane E. Austin1, G. Scott Boomer2, James E. Lyons2, Robert G. Clark3, Stuart M. Slattery4, David W. Howerter4, 1U.S. Geological Survey, Jamestown, ND, 2U.S. Fish and Wildlife Service, Laurel, MD, 3Environment Canada, Saskatoon, SK, Canada; 4Ducks Unlimited Canada, Stonewall, MB, Canada. Contact: jaustin@usgs.gov
Abstract Body: The combined breeding-season populations of greater scaup (Aythya marila) and lesser scaup (A. affinis) (hereafter, scaup) of North America experienced a marked and prolonged decline between the mid-1980s and 2000s. The population’s continental range challenges efforts to understand both the nature of constraints operating on the populations and the temporal and geographic scope of their influences. To tackle the complex issues and scales involved, we have taken a top-down approach in the development of a conservation framework. We structured the annual cycle with a population model consistent with the spatial and temporal scales specified by the conservation plan’s objectives and potential decisions so that it could be used to predict the likely impact of individual management actions or a suite of actions. Demographic parameters represented three breeding regions and three seasons. For each vital rate, we identified possible actions that could affect that rate (e.g., upland cover programs to enhance hen success). We relate effects of actions on vital rates, and hence the continental population, through simple functional relationships. The model structure includes alternative hypotheses about the annual cycle, which can be valuable in assessing different management alternatives. This top-down, model-based approach has highlighted many technical challenges and uncertainties related to model structure, scale, density dependence, and costs and efficacies of actions. The uncertainties and issues identified through this process and in the final plan will help structure future scaup research and management actions and priorities.



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