Posted on 11/25/2009 by Chris Niskanen
The possible effect of climate warming on duck migration is a controversial topic among waterfowl managers and duck hunters alike.
But you can bet Minnesota duck hunters, realizing the season ends next Tuesday, are looking out the window this morning and asking, "What the heck is going on?"
An unusually mild November has stalled the duck and goose migration from Manitoba to Mississippi, and though some waterfowl hunters are finding birds in flooded crop fields, the lack of migration is a head-scratcher.
"We’'re getting an awful lot of calls about our goose count," said John Wollenberg, assistant area wildlife manager at Lac qui Parle Wildlife Management Area in western Minnesota, where the goose season ends Sunday. "Normally, we’d have 100,000 geese here by mid-November. We’re stuck at 40,000. If it’s not the latest migration we’ve had, it’s one of the latest."
Are late migrations the new paradigm for waterfowl seasons? Should managers re-examine the dates when waterfowl seasons begin and end? Should hunters plan on taking their vacations in November rather in October? These and many other questions are swirling around the waterfowl-hunting world.
Michael Schummer doesn’t have the answers, but he is tracking the migration trends that the duck world is talking about. He predicted in August that this would be a mild fall and a late migration, and he’s telling die-hard mallard hunters in Mississippi not to take those hunting vacations in December.
"I’m saying embrace the shoveler and love the gadwall. Those mallards might not show up until the last week in January," said Schummer, a teaching and research associate in the department of wildlife, fisheries and aquaculture at Mississippi State University.
Schummer and other researchers have developed a Web-based duck migration forecast, which is updated every Monday, November through January. It forecasts when migration is likely to occur for mallards and other dabbling ducks in areas from Jamestown, N.D., through Memphis, Tenn.
One thing you won’t get Schummer to do is relate late migrations with climate change.
"It’s an evolving science and in its infancy," he said of the climate change research. "We try to get students and researchers to weigh the evidence and information. It’s controversial."
What Schummer and his associates have done is collect mountains of daily temperature and snowfall data from 1950 to 2008. The data, gathered from the Historical Climatology Network, is being compiled to create a Weather Severity Index that could be used to draw conclusions and make predictions on how temperature and snowfall influence waterfowl migration.
Similar research has been conducted in Minnesota and throughout the country to predict deer deaths during winter months.
In the 1950s, duck hunters experienced similar warm and late-migration periods as today, but trends shifted toward colder and snowy autumns in the 1970s and early 1980s—years that provided memorable seasons for waterfowlers.
But are the warm autumns in the 2000s occurring more frequently? Yes, said Schummer.
"It’s the frequency of these mild events that is increasing," he said. "Last winter was pretty cold, though, but between then and 2000, we had some of the mildest years on record."
And 2009 has been very unusual. Schummer said the U.S. experienced the wettest October ever recorded in 115 years, an event that caused ducks to spread out over a vast area, especially in the Upper Midwest. With mild temperatures in November, those ducks are feeding and aren’t interested in moving because "there is no reason for them to go anywhere," Schummer said.
"This is a very good year for ducks," he said. "There is a lot of food out there and a lot of places to hang out."
So how did Schummer predict this late migration? It’s an El Nino year, when there is a warming of the central and eastern tropical Pacific waters. That pattern brings rain to the Southwest and warm winter weather to the northern states.
How mild can El Nino make the Midwest? At 3 p.m. on Nov. 18, weather stations between Memphis and Jamestown reported temperatures varying only five degrees, from 43 to 48.
"That’s typical of an El Nino year," Schummer said.
But Schummer said there’s a change in weather approaching. The migration forecast predicts a major movement of dabbling ducks other than mallards during this week, and that migration will occur out of higher latitudes and into mid-latitudes, like Missouri, of the Mississippi Flyway.
In other words, you might want to be in the marsh starting on Thanksgiving and through the weekend.