Part One Presented by Michael Schummer: Each year, millions of waterfowl migrate from their breeding grounds in Arctic, northern and mid-latitudes of North America to more southern locales to exploit abundant food and wetland resources as freezing wetlands and snowfall progress north to south. These migrating birds consume and distribute an abundance of seeds and invertebrates, are a cultural resource for waterfowl watchers and hunters, and provide economic benefit through the activities of waterfowl enthusiasts. Recognition of the tangible and intangible importance of this diverse group of birds by waterfowl enthusiasts also gave rise to substantial international efforts to conserve wetlands and associated habitats throughout North America. We developed weather severity indices (WSIs) to estimate autumn-winter distributions of gadwall (Anas strepera), American wigeon (A. americana), American black duck (A. rubripes), mallard (A. platyrhynchos), northern shoveler (A. clypeata), northern pintail (A. acuta), and green-winged teal (A. crecca carolinensis) based on contemporary weather conditions (1980–2000), describe historic changes to weather known to influence their migration (October – April 1979 – 2013), and forecast their future spatial distributions based on dynamically downscaled climate change scenarios (mid-21st [2046–2065], late-21st [2091–2100]). Timing of migration was best explained by WSI models including temperature and snow depth. Our analyses suggest that weather severity known to elicit southerly migration by dabbling ducks has decreased (1979 – 2013) and that arrival of these ducks from Canada into the U.S. and on to more southern latitudes may become delayed by at least a month or more by the late 21st century; such a shift could have substantial ecological, cultural, and economic consequences, and may necessitate changes to North American-wide conservation efforts for waterfowl during the non-breeding period.
Dr. Michael Schummer is a Visiting Assistant Professor of Zoology, SUNY Oswego, a Roosevelt Waterfowl Ecologist, Roosevelt Wild Life Station, SUNY ESF, Syracuse, NY and Adjunct Professor, SUNY ESF, Syracuse, NY
Part Two Presented by Michael Notaro: An investigation was performed of the potential impacts of changing weather severity on waterfowl migration, aimed at achieving actionable science to guide the decisions of resource managers. The Northeast Climate Science Center-supported project consisted of a collaborative effort among researchers and stakeholders at the University of Wisconsin-Madison, State University of New York at Oswego, Long Point Waterfowl, Ducks Unlimited, and the Michigan Department of Natural Resources. Specifically, projected changes in the relative abundance and timing of autumn-winter migration were assessed for seven dabbling duck species across the Mississippi and Atlantic Flyways for the mid- and late 21st century. The project methodology consisted of (1) establishing species-specific observed relationships between cumulative weather severity in autumn-winter and duck population rate of change; (2) developing high-resolution, dynamically downscaled projections of weather severity; and (3) merging this information to estimate future changes in the timing of autumn-winter migration due to projected changes in air temperature, snowpack, and lake ice cover. Delayed autumn-winter migration was projected for all species, with the least delays for the Northern Pintail and the greatest delays for the Mallard. Implications of these changes in migratory behavior on food resources, wetland restoration, hunting, and birdwatching were explored.
Dr. Michael Notaro is the Associate Director and Senior Scientist of the Nelson Institute Center for Climatic Research at the University of Wisconsin-Madison. He received his PhD in Atmospheric Sciences in 2002 from the State University of New York at Albany. His areas of expertise include global and regional climate modeling, climate change impacts on the Great Lakes and ecosystems, lake-effect snow, and land-atmosphere interactions.