For Minnesota's ruffed grouse hunters, it might not get much better than this. ¶ The "Ol' Ruff" population is up a remarkable 43 percent from last year, based on spring drumming counts, and the population index is the highest it's been in 37 years. ¶ This is the fourth consecutive increase, and the grouse population probably is at or near the peak of its 10-year boom-to-bust cycle. That means the hunting season, which opens Saturday, could be one of the best in decades.

"I think we'll see a noticeable increase in birds out there, said Dan Dessecker of Rice Lake, Wis., an avid grouse hunter and director of conservation policy for the Ruffed Grouse Society.

Said Dave Schad, Department of Natural Resources fish and wildlife section chief: "Hopefully, we're approaching one of those really special years with peak bird abundance. I think there's a lot of excitement and a lot of interest.''

But two key questions remain: Will hunters actually find significantly more grouse this fall? And how many hunters will show up in the woods to seek them?

The last time the grouse index was nearly this high, in 1998, an estimated 142,000 hunters bagged almost 1 million grouse.

Yet no one expects that kind of harvest this fall. A major reason: Despite the expected huge increase in bird numbers, it's highly unlikely that 142,000 hunters will show up. Though grouse hunter numbers historically have climbed and dropped along with the grouse population, the long-term trend has been a decline in small-game hunters.

Last year, the DNR estimated there were 87,000 grouse hunters -- or 55,000 fewer than 11 years ago. And the agency sold 290,000 small-game licenses in 2008, 30,000 fewer than in 1998.

Last year, grouse numbers also were up from 2007, but hunter numbers dropped slightly.

"Hunter numbers tend to lag a year behind the [grouse] cycle," Dessecker said. "People hear about a great year, and the next year they buy a license. My guess is we'll see a big bump this year, both in harvest and hunter numbers."

But with fewer hunters, he guesses Minnesota hunters might harvest 400,000 birds -- not 1 million.

"Since 1985, we've lost 56 percent of our small-game hunters nationwide," Dessecker said. "That drastic of a decline in such a short time is just frightening."

Then there's the question of whether hunters actually will find significantly more birds. For the past two falls, hunters were expected to bag more than a half-million ruffies, based on spring counts. Yet hunters shot 40 percent fewer birds, averaging just over 300,000 grouse. And the past two years, there's been anecdotal reports that hunters simply weren't finding the number of birds that they expected to see, given the good spring drumming counts.

Dennis Simon, DNR wildlife management section chief, said officials can't explain that.

"There's some suspicion that it's related partly to level of effort -- maybe they're not hunting as intensively as they did -- but we don't know that for sure," he said. "Last year, particularly after the first couple weeks of the season, there was a fair amount of pessimism, and I think that does have an effect [on hunting effort]."

There was no biological reason that the grouse weren't there, he said. And the birds clearly were there this spring when the drumming counts were done.

In 1996 -- the last time the grouse index was the same as it was last year -- hunters bagged 533,000 grouse. But there were 31,000 more hunters than last year. Hunters last year averaged 3.7 birds apiece, compared to 4.5 birds in 1996. In 1998, the last grouse population peak, hunters averaged 6.7 birds apiece.

For hunters, new-growth aspen provides prime grouse habitat, and there's been less timber harvesting recently due to declines in the wood products industry and changes in logging policies, especially on federal lands. Still, Dessecker is optimistic.

"Minnesota is still a destination state for grouse hunting -- we have more good quality grouse habitat than any other state," he said. "Minnesotans should take advantage of that."

Doug Smith • dsmith@startribune.com