For years, officials figured up to 25,000 youngsters participated in Minnesota's Youth Waterfowl Day -- a one-day kids-only hunt.

Now it appears less than half that number participate each fall.

"It looks like there are dramatically fewer kids out there," said Tom Landwehr, Department of Natural Resources commissioner.

The special one-day hunt, held two weeks before the regular duck opener, allows youths age 15 and under to hunt waterfowl while accompanied by non-hunting adults. The idea is to encourage youngsters to take up waterfowl hunting. But since it began 15 years ago, some hunters have argued it isn't needed and the early shooting disturbs and disperses ducks before the regular duck opener, resulting in poorer opener.

But the DNR has new numbers showing far fewer young waterfowl hunters participate in the event. Last year, the DNR began requiring youths age 15 and under to get a free small-game license, allowing the agency, for the first time, to track the number of young hunters. The DNR handed out 18,336 free licenses. Officials then checked to see how many licenses were distributed before the Sept. 18 Youth Waterfowl Day, and how many of those were HIP-certified, as required to hunt waterfowl.

The answer: About 5,500.

But that number likely is low, officials said, because the license requirement was new and some youths likely either didn't get one or weren't aware they had to.

"Even if we double the number to 10,000, it's much lower than people had anticipated," Landwehr said. "And if it's that few, it's really hard to make an argument that there's an impact to waterfowl."

The estimates of 25,000 Youth Waterfowl Day hunters were based on postseason duck hunter surveys -- in which adult respondents clearly exaggerated participation, either because of poor memory or "prestige bias" in which they want to put a positive spin to a question.

A bill approved by the Minnesota House last week would allow the DNR to open the duck season a week earlier. Current law allows the season to open the Saturday closest to Oct. 1. The bill would allow the season to begin the Saturday nearest Sept. 24. This year, that's Sept. 24.

"If the Legislature allows us, I don't know why we wouldn't," Landwehr said. An earlier season would give hunters a better chance at early migrants, such as teal and wood ducks. "We'd likely seek public input on it at a meeting or website poll," Landwehr said. But he said the newly formed 15-member citizens waterfowl focus group supported the idea. Landwehr met with the group last week to discuss hunter recruitment and retention issues, including Youth Waterfowl Day.

The youth event is held two weeks before opener, to minimize impact on the opener. So if the regular duck opener is Sept. 24, that would push Youth Waterfowl Day to Sept. 10 -- the earliest duck hunt in modern times.

Repeal amendment? A bill has been introduced in the Legislature to repeal the Clean Water, Land and Legacy Amendment, passed by voters in 2008. The bill by Rep. Tom Hackbarth, R-Cedar, would ask voters whether to amend the state constitution again to remove the Legacy Amendment and its three-eighths of 1 percent sales tax. With the 2011 session nearly over, it's unlikely the bill will be taken up this session.

Doug Smith • dsmith@startribune.com