Hot Topic: Climate Change and Duck Season

Anyone who was slapping mosquitoes in Stuttgart in late December, wondering what happened to duck season, was hardly alone.

Blame it on a string of unusual weather patterns, climate change or just bad luck, one thing's for certain: This winter was warm, and record numbers of ducks in the north country didn't always translate to a great hunting season as a result. The average temperature for December in Bismarck, N.D., for example, was 9 degrees above normal. On Jan. 4, it reached a record 60 degrees, 16 degrees above the previous record set in 2001. Minneapolis, Minn., was more than 8 degrees above average last December and Arkansas experienced its ninth warmest year on record in 2011. Overall, 2000 to 2009 was the warmest decade ever recorded, according to the National Oceanic and Atmospheric Administration.

That spelled poor hunting throughout much of the country as ducks and geese took advantage of open water and abundant food in Canada and the northern U.S. A mid-season survey conducted in early January by the Illinois Department of Natural Resources found just 3,700 ducks on three lakes in the central zone, down from the five-year average of 56,000! Some birds did fly south eventually, but not until the last few weeks of the season. In some states, those seasons were already closed.

That's got more than a few hunters wondering if wildlife managers should consider restructuring duck seasons, shifting the later splits to accommodate later migrations. Avery territory manager Mark Brendemuehl, who lives and hunts in Minnesota, says a delayed second season split would have been "a godsend" this year.

"We had a good number of local birds early, but once they got pushed out by hunting pressure, nothing moved in to replace them," he said. "We did get some migrators, but not really enough to refresh the areas we were hunting."

He's not alone. According to IDNR's waterfowl biologist Ray Marshalla, more and more hunters are asking for a later season. He hears about it mostly during warmer years, but overall, hunters are clearly concerned.

"We have shifted seasons later over the last 15 years or so and our data is showing that average freeze-up dates are taking place later," he says. "However, it's still a crap-shoot to some extent because we experience fairly wide extremes from year-to-year."

That's one reason Brendemuehl isn't sure if shifting the season to later dates would be a good thing in the long run. Despite this year's warm winter, the past few years have been about normal or even colder.

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Everything froze up solid two or three years ago, effectively ending the season before it was over, he recalls. "Most people I talk to agree, it would probably be better to move the second season dates back a little bit, but you just never know."

Marshalla and other state waterfowl biologists are in a difficult position when it comes to setting season dates. The U.S. Fish and Wildlife Service sets season guidelines that cover a wide time frame, allowing state agencies to set dates within that window and within the allowable number of hunting days. For instance, in the Mississippi Flyway states are given 60 days that could fall anywhere between late September and the last Sunday in January. Northern states typically set their seasons early since birds are usually gone by mid- to late December. Southern states push their seasons toward the end of the allowable time frame to account for late-arriving birds. Biologists, however, can't say if duck migrations are taking place later on average. In fact, Marshalla says most species do seem to be migrating about the same time as they always have.

"Mallards seem to be migrating south at later dates, but that may have to do with changes in farming practices as much or more than climate change," he notes. "I'm not sure if it's possible to measure."

No studies have looked at migration dates and weather patterns, mostly because it's difficult to gather enough data to make any sound conclusions. There have been attempts to look at harvest data in an effort to examine migration patterns, but they did not show any conclusive evidence that ducks were migrating south later, either.

If harvest figures from Louisiana are any indication, this warm winter was nothing more than an anomaly. Hunters in that state killed a record number of ducks last year, over 2.7 million, which was part of a steady upward trend since 2004, when the harvest was 822,000. Arkansas hunters have experienced equally good hunting as indicated by harvest figures over the last decade. If warming trends are a factor, harvest figures would likely go down, particularly in the South.

That's not to say future migrations won't be affected by a warming earth. A report by Ducks Unlimited paints a grim future for both nesting and wintering habitat. Scott Yaich, DU Director of Conservation Operations, says we are already seeing the effect of climate change, including significant marsh loss along the Louisiana coast due to sea level rise, changes to permafrost in the Arctic and loss of wetlands in the boreal forest.

"We are seeing and will likely see more weather extremes. Although it's difficult to predict, most models suggest drier weather in the future," he says. "If we lose nesting habitat as a result, it's not good for the future of ducks and duck hunting."

Yaich warns that pushing seasons later, particularly in the southern U.S. where seasons already run until the end of the federal framework, could have a detrimental effect on ducks as a whole. Wood ducks are already nesting in some states by late season, and many duck species have developed pair bonds in late January. Disrupting those pair bonds could mean fewer ducklings on the nesting grounds in the spring.