Representation, redundancy, and resilience :waterfowl and the National Wildlife Refuge System /by Abba B. Pidgorna.

Abstract

The National Wildlife Refuge System (NWRS) is a network of 545 protected areas designated to manage and protect wildlife in the U.S. The 1997 NWRS Improvement Act requires the NWRS to be managed in a manner consistent with the preservation of its biological integrity, diversity, and environmental health. I used the principles of representation, redundancy, and resilience as indicators of biological integrity and diversity of 43 waterfowl species on NWRS lands. Waterfowl plays an extremely important role in the life of the American public and has been a priority conservation target for the NWRS for over 70 years. I evaluated the representation and redundancy of waterfowl species on National Wildlife Refuges (NWRs) at three geographic/ecological (national, flyway, and climatic) and two temporal (all-season and breeding) scales. The assessment of resilience included three parameters: the proportion of a waterfowl species' range captured by the NWRS, the number of cities and interstate highways in proximity to refuges, and the projected changes to the breeding ranges of waterfowl on the NWRS as a result of global climate change. I found that waterfowl species occur on at least 45% of NWRs in their all-season range. Ten waterfowl species, eight of which were dabbling ducks, occurred on two or more NWRs across all scales of analyses. Ten waterfowl species had at least 10% of their all-season range and 17 species had 10% of their breeding range in the U.S. captured by the NWRS. NWRs in the Central Flyway and in Alaska had the lowest number of cities and interstate highways in their surrounding 50- and 10-km buffers. Forty-one waterfowl species were projected to retain some part of their breeding range on the NWRS as a result of global climate change. One species, the spectacled eider, was projected to lose its breeding range from the NWRS.;Although the NWRS was designed to capture waterfowl diversity at a multitude of scales, it will not be sufficient to maintain waterfowl populations in perpetuity, especially in the face of global climate change. Therefore, steps must be taken to strengthen the NWRS primarily by incorporating the surrounding matrix into the design of the NWRS through collaborative conservation partnerships with surrounding landowners.Thesis (Ph. D., Environmental Science)--University of Idaho, May 2007