Early Saturday morning, Minnesota's most recent duck hunting experiment will continue.

Amid a forecast by the U.S. Fish and Wildlife Service that North America this spring was home to a record population of breeding ducks, Minnesota waterfowlers, having suffered through many subpar duck seasons, will nonetheless keep their expectations in check.

No record harvest is expected here.

Instead, come opening morning, hunters will scan state skies for representative samples of one or more of Minnesota's "Big Three'' duck species: mallards, wood ducks and blue-winged teal, which annually are the most abundant fowl in Minnesota hunters' bags.

This year, as in each season since 2011, Minnesota waterfowlers will be allowed three wood ducks and four mallards daily, including two hens.

Before 2011, Minnesota hunters were allowed only two woodies and one hen mallard daily, with twice that number in possession.

Now, possession limits are triple the daily limits.

Another big change:

Since 2011, Minnesota duck season opening-day shooting hours have begun a half-hour before sunrise. Previously, state hunters had to hold their opening-day fire until 9 a.m. and, before that, until noon.

The later starting hours were long supported by Minnesota waterfowl managers who believed they helped distribute the harvest of local ducks over a longer period of time.

The same managers believed Minnesota duck hunting should begin on the Saturday nearest Oct. 1.

Now it opens on the Saturday nearest Sept. 24.

These "old-time'' Minnesota waterfowl managers believed it unwise to open duck hunting too early in September, or to allow shooting too early on opening morning.

Doing so, they believed, would concentrate too much of the state's hunter harvest on birds that breed here, believing the harvest of these birds is better spread more proportionately throughout the flyway during migration.

That way, a greater percentage of the state's breeding ducks likely would return to Minnesota in spring, year after year.

Much of this thinking was discarded beginning in 2011 with duck-hunting changes driven by Department of Natural Resources Commissioner Tom Landwehr, an avid waterfowler and onetime Ducks Unlimited staffer who began his DNR career as a wildlife biologist.

Landwehr's season and bag-limit alterations, he said in 2011, would give hunters more and better opportunities to harvest teal and wood ducks particularly, both of which are early migrators. The extra hen mallard in hunters' daily bags, Landwehr said, would perform a similar service, i.e., give more hunters more chances to kill more ducks.

Biologically, Landwehr said, Minnesota ducks could withstand the higher limits — an assertion that might or might not ultimately prove true.

Landwehr sought the changes in part because Minnesota had lost some 40,000 duck hunters over the previous 10 years.

Giving hunters more opportunities to kill more ducks, particularly early in the season, when a greater percentage of the state's waterfowlers are afield, might help retain some hunters, while perhaps encouraging others to return to the fold.

Landwehr's doubters thought otherwise. They suggested the changes amounted to little more than an attempt by the DNR to boost license sales while trying to "shoot their way to more ducks.''

Their thinking was that Minnesota — which traditionally has been home to more duck hunters than any state — didn't have a duck-limit or duck-season problem. It had a duck-shortage problem, driven largely by multiple generations of wetland and other habitat losses.

In part, they believed, these losses were made possible by doormat conservation leadership at the DNR and, especially, by a state Legislature that too often is beholden to the bidding of farm groups.

This view held that instead of attempting to make it easier for the state's remaining hunters to kill the state's remaining ducks, the DNR and other state agencies should change duck hunting regulations in entirely different ways, while also far more aggressively protecting, enhancing and restoring habitat.

Example: Perhaps duck hunting statewide should end at noon each day, or by early afternoon, so more ducks, resident as well as migrant, would stay in the state for longer periods of time.

Similarly, perhaps state waterfowl refuge areas should be considerably expanded, while also further restricting motorized traffic on game lakes — ideas that might not sit well with some duck hunters but might make the state far more duck-friendly.

• • •

So what's happened since the DNR changed the duck season and duck limits in 2011? Conclusions are difficult to draw in such a short period. But impressions are possible. Let's take a look:

• In 2011, the total state duck harvest was 621,000. In 2012, it was 749,000; in 2013, 607,000; and in 2014, 571,000.

• Total active Minnesota duck hunters, according to the Fish and Wildlife Service, were 76,800 in 2011; 77,700 in 2012; 52,200 in 2013; and 65,300 in 2014.

• Total duck hunter days afield: In 2011 in Minnesota, the number was 401,100. In 2012, 503,200. In 2013, 312,110. And in 2014, 349,400.

• And the seasonal duck harvest per hunter? In 2011, 8; in 2012, 9.6; in 2013, 11.6; and in 2014, 8.7.

• • •

Here's a breakout of Minnesota's Big Three duck species during the same period, 2011-2014.

First, mallards …

• The DNR's estimated mallard breeding population (from aerial surveys conducted over 40 percent of the state) this spring was 206,000, 20 percent below last year's 257,000 mallards, 17 percent below the 10-year average, and 10 percent below the long-term average of 228,000.

• Mallard harvest (all harvest numbers are statewide), meanwhile, has dropped in Minnesota since 2011 (see accompanying chart), when it was about 180,500. Since then, it's been 197,320 in 2012; 166,366 in 2013; and 161,859 in 2014.

• The modern-day Minnesota record mallard harvest occurred in 1972, when 355,000 were killed, followed as recently as 2001, when 327,000 were felled.

And then wood ducks …

• The estimated Minnesota wood duck breeding population in 2011 was 89,300. In 2012, the count was 66,000. In 2013, 144,200. In 2014, 56,300. And in 2015, 69,500.

• The wood duck harvest in 2011, the year the Minnesota limit was raised from two daily to three, was 150,590, up more than 70,000 from 2010 and an increase of more than 100,000 from 2009. In 2012, harvest rose again, to 184,400, before falling in 2013 to 149,680. Last year it was 114,620.

• The record Minnesota wood duck harvest occurred in 1984, at 185,440.

Finally, blue-winged teal …

• The state's estimated blue-winged teal breeding population this spring was 169,000, 66 percent higher than last year's estimate of 102,000. Bluewings were 14 percent above the 10-year average and 21 percent below the long-term average of 212,000.

• The teal harvest in 2011 was 89,767, up from 36,960 in 2010. In 2012, the kill rose to 123,322. In 2013, the harvest was 114,360 and last year, 82,030.

• The record Minnesota bluewing harvest of 179,360 occurred in 1971.

Dennis Anderson • danderson@startribune.com