A BIOENERGETIC MODEL USED TO EVALUATE MANAGEMENT STRATEGIES FOR WINTERING WATERFOWL AT SEQUOYAH NATIONAL WILDLIFE REFUGE, VIAN, OKLAHOMA

A primary focus of Sequoyah National Wildlife Refuge (SNWR) is to provide habitat and foraging opportunities for waterfowl and other wetland dependent species. SNWR currently meets this objective by providing wetland and agricultural habitat. Wetland restoration and enhancement projects have occurred in recent years, with the intent to sustain healthier and more diverse waterfowl and wildlife populations. However, the relationship between habitat and food availability relative to waterfowl presence has yet to be quantified. This information is necessary to determine how SNWR can best manage refuge habitats for wintering waterfowl populations to ensure the available foraging resources on the refuge or within the surrounding landscape are sufficient to meet the energetic demands of waterfowl populations. Specifically, our goal was determine current carrying capacity for wintering waterfowl provided by SNWR relative to the surrounding landscape within the foraging flight distance of focal species: mallard, gadwall, and snow geese. Models included in this study emphasized efficient land use and maximization of resources within the SNWR refuge boundary in consideration of food resources available with the FFD of wintering waterfowl (e.g. Johnson et al. 2014). Specifically, we calculated the current energetic carrying capacity within Sequoyah and the surrounding FFD to determine to contributions of on-refuge agriculture relative to native wetland habitat types. We then determined the energetic effects of reductions in the area farmed on the refuge, changes to crop type and proportion (i.e., green browse versus standing grain) planted on the refuge, changes to the timing and proportion of standing crops mowed during the winter period, and hypothetical reductions in crop yield that could result from implementation of National Wildlife Refuge System policy eliminating the use of neonicotinoid coated and/or genetically modified seeds. To offset energetic losses associated with reductions or changes to on-refuge agricultural production, we determined the energetic gains associated with the creation of one passive and one actively managed wetland. Our model outcomes can be used to guide land management and restoration decisions and be incorporated into Habitat Management and Comprehensive Conservation Plans.