CONSERVATION ACTION PLAN for the AMERICAN BLACK DUCK, First Edition 2011
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CONSERVATION ACTION PLAN FOR THE AMERICAN BLACK DUCK, First Edition 2011 U.S. Fish and Wildlife Service Division of Migratory Bird Management Prepared by: Patrick K. Devers (U.S. Fish and Wildlife Service) Brigitte Collins (Environment Canada-Canadian Wildlife Service) American Black Duck Conservation Action Plan EXECUTIVE SUMMARY The American black duck (Anas rubripes) was selected as a Focal Species due to its conser vation need, representation of salt-marsh and boreal species needs, and high level of current program effort and existing partnerships. The black duck population experienced a severe decline of >50% between the 1950s and 1990s. Today, the black duck population appears stable but below desired abundance. Monitoring data including spring abundance, winter abundance and productivity paint a mixed picture of the stability and sustainability of the population. Researchers and managers have not reached consensus regarding current limiting factors. Major threats to the black duck include, but are not limited to: • Loss and degradation of boreal forest (i.e., breeding grounds) due to economic devel opment including hydro-electric, mining, timber, and agricultural activities. • Loss and degradation of wintering grounds, particularly coastal salt marsh due to urban expansion, pollution, recreational activities, and sea-level rise. • Predicted changes due to climate change, including shifts in temperature and pre cipitation patterns and phenology that will exacerbate current limiting factors and potentially expose black ducks to novel limiting factors such as diseases. Priority conservation and management actions include: • Development of a revised breeding population goal based on the best available science. • Development of harvest and habitat adaptive management frameworks to guide deci sions and reduce key uncertainties. • Improvement of monitoring programs designed to provide estimates of seasonal survival and productivity. • Development of monitoring programs to estimate energetic carrying capacity on win tering grounds. USFWS Focal Species Program 2 American Black Duck Conservation Action Plan • Research to understand and quantify functional relationships between habitat features, habitat management, vital rates, and density. • Protection, restoration and enhancement of key land parcels on breeding grounds, migration routes and wintering grounds. Suggested citation: Devers, P. K., and B. Collins. 2011. Conservation action plan for the American black duck, First Edition. U.S. Fish and Wildlife Service, Division of Migratory Bird Management, Laurel, MD, USA. Front cover photo: American black duck (Photo Credit D. Bordage, CWS) ; this page: American black duck breeding habitat in the boreal forest of central Quebec (Photo Credit P. K. Devers, USFWS). USFWS Focal Species Program 3 Contents EXECUTIVE SUMMARY ........................................ 2 ACKNOWLEDGEMENTS ........................................ 9 INTRODUCTION ............................................. 10 POPULATION STATUS ......................................... 11 NATURAL HISTORY ........................................... 14 Taxonomy ............................................... 14 Life History .............................................. 16 LIMITING FACTORS ........................................... 21 Habitat Loss ............................................. 22 Habitat Degradation ......................................... 28 Inter-Specific Competition ...................................... 30 Harvest ................................................ 31 CONSERVATION STRATEGIES AND ACTIONS ........................... 32 Population Goal ........................................... 32 Management Actions and Strategies ................................ 33 PROGRESS EVALUATION ....................................... 40 LITERATURE CITED .......................................... 41 APPENDIX A: Habitat management goals and needs for the Atlantic Coast Joint Venture planning area .................................................. 50 APPENDIX B: Habitat management goals and needs for the Eastern Habitat Joint Venture plan- ning area. ............................................... 121 APPENDIX C: Habitat management goals and needs in the Upper Mississippi River and Great Lakes Joint Venture planning area. ................................. 123 APPENDIX D: Habitat management goals and needs in the Central Hardwoods Joint Venture planning area ............................................. 124 APPENDIX E: Habitat management goals and needs in the Appalachian Mountains Joint Venture planning area.............................................. 125 4 American Black Duck Conservation Action Plan APPENDIX F: Habitat management goals and needs identified in the Chesapeake Bay Executive Order Strategy (Department of Interior 2010). 126 USFWS Focal Species Program 5 List of Tables 1 States that have identified the black duck as a “Species of Greatest Conservation Need” as part of their State Action Plans. ............................... 13 2 Taxonomic hierarchy of the black duck. ............................. 16 3 Summary of black duck survival rates. ............................. 19 4 Partial list of black duck food items (from Longcore et al. 2000a, Eichholz et al. 2010). 20 6 List of Figures 1 Distribution of the American black duck (from Longcore et al. 2000a). Breeding areas shown in blue, breeding and wintering areas in green, and wintering areas in orange. 12 2 Estimates of black duck winter abundance based on the Mid-Winter Inventory, 1955— 2010. 12 3 Estimates of total indicated breeding black ducks based on the Integrated Eastern Wa terfowl Survey, 1990—2010. 14 4 Trend in pre-season age ratios of black ducks harvested in the U.S., 1975—2008. 15 5 Black duck nest in the Chesapeake Bay, VA, 2006. 17 6 Black duck breeding habitat in central Quebec, 2008. 21 7 Conceptual diagram of black duck population dynamics and immediate (e.g., habitat loss via hydro-electric development and urbanization) and emerging limiting factors (e.g., habitat loss via climate change). 23 8 Conceptual impact of decreasing carrying capacity (through habitat loss or degradation) on black duck vital rates (i.e., reproduction and survival). Top left: Habitat loss reduces carrying capacity and results in a more rapid reduction of recruitment related to density. Top right: Habitat degradation results in a lower carrying capacity and lower recruitment across all densities. Bottom left: Habitat loss results in a more rapid decrease of annual survival relative to black duck density. Bottom right: Habitat degradation results in lower survival across all ranges of density. Dashed blue line indicates density independent survival (top left and right) or recruitment (bottom left and right). Adapted from Anderson et al. 2007. 24 9 Examples of habitat loss in the boreal region of eastern Canada; (top) heavy metal mining, (bottom) deep water reservoir created by hydro-electric dam. 26 10 Factors resulting in the loss of forest land, including forested wetlands, in the eastern U.S., 1973–2000 (reproduced from Drummond and Loveland 2010). 27 7 American Black Duck Conservation Action Plan 11 Example of clear cuts in Quebec - timber harvest increases forest edge and travel corridors for mammalian predators and increases disturbance which may negatively impact black ducks. ......................................... 29 USFWS Focal Species Program 8 American Black Duck Conservation Action Plan ACKNOWLEDGEMENTS We thank the following individuals who contributed to the development of this report by providing infor mation and data and comments on earlier drafts: Daniel Bordage (Environment Canada-Canadian Wildlife Service), Greg Soulliere (U.S. Fish and Wildlife Service), Tim Jones (U.S. Fish and Wildlife Service), Marcel Darveau (Ducks Unlimited Canada), and Mark Gloutney (Ducks Unlimited Canada). We also recognize the Atlantic Coast Joint Venture, Eastern Habitat Joint Venture, and Upper Mississippi and Great Lakes Joint Venture for the development and use of their habitat conservation delivery plans for black ducks. USFWS Focal Species Program 9 American Black Duck Conservation Action Plan INTRODUCTION The U.S. Fish and Wildlife Service (USFWS) Division of Migratory Bird Management (DMBM) initiated the Focal Species Program (FSP) in 2004. The FSP was developed in direct response to a recommendation from the Office of Management and Budget to develop new, stronger performance measures to evaluate program success. The DMBM proposed to the Office of Management and Budget to use the FSP to systematically identify and implement management activities to improve the status of select migratory bird species and demonstrate the depth and breadth of management challenges faced by the USFWS and its partners (U.S. Fish and Wildlife Service 2007). Species that met ≥ 1 of the following criteria were included in the FSP: 1) high conservation need, 2) representative of a broader group of species sharing the same or similar conservation needs, 3) high level of current program effort, 4) potential to stimulate partnerships, and 5) high likelihood that factors affecting status can realistically be addressed. Based on these criteria and after broad consultation the DMBM identified 139 focal species to emphasize in the short term (U.S. Fish and Wildlife Service 2007). The American black duck (Anas rubripes; hereafter black duck) was selected as a Focal Species due to its conservation need, representation of salt-marsh and boreal