As global warming and climate change debates continue to "heat up" worldwide, researchers at Mississippi State are examining how weather influences duck migration patterns.
"In the past few years, we have observed that ducks are not migrating to southern latitudes in abundance, or are doing so generally only in the presence of severe weather," said Rick Kaminski, a senior waterfowl ecologist at the university.
"Our initial thoughts were that ducks were remaining at northern latitudes as a result of warmer weather, available food and habitat, among other factors," added the James C. Kennedy Endowed Professor in Waterfowl and Wetlands Conservation.
To test the theory, Kaminski and Mike Schummer, a post-doctoral research and teaching associate in MSU’s Forest and Wildlife Research Center, recently began examining influences of weather variables on fall-winter duck migration.
"Our project goal is to increase our understanding of duck migration patterns for planning habitat and hunting management," Schummer said.
The research team set out to identify weather variables or their combinations that best explained rates of change in abundance of mallards and other dabbling ducks at mid-latitude regions in the Mississippi Flyway.
The results soon will be published in the Journal of Wildlife Management. The publication has been produced since 1937 by The Wildlife Society of Bethesda, Md., one of the world’ leading scientific organizations.
Two other objectives of the MSU project included determination of patterns and long-term trends in a weather severity index and, using a variety of climate projections, the computer modeling of potential future duck-population distributions throughout North America.
From all this, the MSU research team has developed an immediately usable tool to predict waterfowl movement patterns. The new Web-based Duck Migration Forecast includes a five-day outlook to indicate when mallards and other dabbling ducks will journey south.
Using 10 years of survey data provided by the Missouri Department of Conservation and weather data from U.S. Historical Climatology Network Stations, MSU and Missouri collaborators found that cumulative effects of snow and temperature, as well as the duration of these events, best explain the rate of change in duck abundance.
"Our findings suggest that dabbling ducks, including northern pintail, gadwall and green-winged teal, migrate prior to freezing conditions or snow, while mallards generally migrate when freezing temperature and snow persist for several days," Kaminski said.
The scientists collaborated with meteorologists in MSU’s geosciences department to look at the weather severity index for the past 50 years to add clarity to the habitat-vs.-climate debate.
Though the study is ongoing, preliminary data suggest that most winters since the late 1990s have been warmer than the 50-year average.
"The forecast includes areas from North Dakota to Western Tennessee, and predicts the likelihood of duck migration down the Mississippi Flyway," Schummer explained.
When complete, the research project should enable U.S. biologists and managers to better determine where and when habitat should be made available for migrating and wintering ducks.
It also will allow hunters—whether residing in big cities or rural communities—to determine the best days to take to the flyways in search of waterfowl.