A professor from the University of Montana had a simple message Tuesday in Arkansas: if you like hunting ducks, support international efforts to prevent global warming.

Wildlife biologist David E. Naugle said that if global temperatures rise, duck breeding grounds in North America will dry up, greatly reducing duck populations.

He said the best way to solve the problem is to work with other countries to reduce carbon dioxide emissions.

"This is a global problem that's going to require global solutions," he said.

Naugle's trip to Arkansas was paid for by the Natural State Coalition, a new group that's dedicated to combatting global warming.

Most scientists say carbon dioxide produced by burning fossil fuels like coal and oil traps heat in the atmosphere, which leads to increased surface temperatures.

In Arkansas, duck hunting is both a beloved pastime and a source of income for businesses that depend on hunters' dollars.

In the eastern Arkansas town of Stuttgart, for instance, the annual Wings Over the Prairie Festival draws thousands of people for a festival that includes a highly competitive series of duck calling contests.

Speaking near a park pavilion on the banks of the Arkansas River, Naugle described research he and associates published last fall in the scientific journal BioScience.

The research focused on the prairie pothole region, which includes parts of Iowa, Minnesota, Nebraska, North Dakota and South Dakota as well as the Canadian provinces of Alberta, Manitoba and Saskatchewan.

The region, which includes large swaths of wetlands, is the breeding ground for 50 percent to 80 percent of the ducks that migrate to Arkansas each year, Naugle said.

A 95-year climate history of the region shows that it has become warmer on average, he said.

Researchers produced computer models that tested what would happen if average temperatures rose 3 degrees Celsius.

The result: the available breeding ground for ducks would shrink dramatically. The breeding ground would shrink even further if precipitation decreased 20 percent at the same time, he said.

That would mean hunters in Arkansas would see smaller duck populations.

Last month an aerial survey in Arkansas counted 289,589 ducks, about half as many as last year. State officials blamed the low numbers on a drought.

Naugle said the current low duck population isn't necessarily related to global warming: It may be due to the local drought, changes in bird migration patterns and changes in the way rice farming is conducted.

However, global warming remains important.

"If we can't produce the ducks on the breeding grounds, it's a moot point where they go after this," he said.

The Natural State Coalition is led by Robert McLarty and has existed for only two months. McLarty, 30, has worked as a political consultant and said he wants to create a coalition of duck hunters, bird watchers, environmental organizations and other groups to educate the public on global warming.