Anderson: Telling female and male mallards apart in September is a tough problem for hunters to duck in Minnesota

The hens aren't coming home to roost, and something's going to have to change.

Beginning in Minnesota.

The hens in this case are mallards, specifically adult hen mallards, and their absence on the breeding grounds, including in Minnesota, the Dakotas and prairie Canada, means trouble for duck hunters and duck hunting.

It's trouble that can no longer be denied, especially in Minnesota, where breeding mallards were down 40% this spring from the long term average, and where in 2011, under the direction of then Department of Natural Resources Commissioner Tom Landwehr, duck hunting restrictions were loosened in an attempt to stem the loss of state waterfowlers.

Interest among Minnesotans in duck hunting has declined as duck numbers have fallen. In 1980, Minnesota licensed nearly 150,000 duck hunters, a tally that by 2010 had fallen to about 80,000.

Landwehr's novel plan to have the state shoot its way to more ducks — and more duck hunters — has worked so well that as Minnesota's early teal-hunting season opens Sunday, the state has some 20,000 fewer waterfowlers than it did in 2011.

That's when the DNR opened the regular duck season in September rather than in October, allowed shooting to begin one-half hour before sunrise — a time when Superman, with his x-ray vision, can't distinguish female mallards from males, which haven't yet developed their iconic green heads and other plumage — and increased the daily hen mallard limit from one to two.

In attempting to make it easier for hunters to kill mallards and other fowl, Landwehr, like some other waterfowl managers nationwide, mistook duck hunters for fools.

Rising before dawn on October and November mornings to gather their retrieving dogs, pile gear into trucks and drive to cold, windblown marshes, waterfowlers want at least to see some ducks in the sky for their efforts. For them, a few birds pitching and wheeling over their decoys and the ambiance of passing a good time with friends in dank surroundings, wet dogs at their knee, is quite enough.

None of which is possible without habitat conservation, whose never-ending battles with agriculture and development are the proper province of waterfowl managers — not carnival barking for license sales.

Todd Arnold gets it.

Arnold is a University of Minnesota professor whose specialty is divining salient information from the reams of waterfowl and waterfowl-hunting data produced annually by the U.S. Fish and Wildlife Service.

Here's what Arnold says:

• Too few hen mallards are returning north in spring to raise broods, a development exacerbated in recent years by a continuing loss of wetlands and other habitats, complicated by drought.
• The severity of recent hen mallard population declines might have been masked by state and federal springtime aerial population survey methodology that counts unseen hens for each seen drake (male), believing the hens are hidden on nests. In fact, the unseen hens might have been unseen because they didn't exist.
• Minnesota hunters might be contributing to the state's mallard problems because more than half the mallards they shoot are raised in Minnesota. State duck hunting seasons and limits developed by previous state waterfowl managers — the late Roger Holmes, Dave Vesall and Art Hawkins, among others — favored a noon opener on the season's first day, with a 4 p.m. closure for a few weeks thereafter to limit the Minnesota harvest of Minnesota-reared ducks. Allowing ducks to rest in evenings before the migration began in earnest was considered important because hen mallards generally return to the same nesting areas annually. Protecting some of these birds in the early season meant their harvest was more likely to be scattered proportionally across various states, ensuring some of these ducks would return to the state in spring to nest.
• Hunters across the northern tier of states, including Minnesota, might also be contributing to a related problem in recent decades by using spinning wing decoys. Juvenile ducks are particularly vulnerable to these motorized duck replicas, resulting in a disproportionate harvest in the north. One result is that hunters in the south don't encounter as many juvenile birds, which places more harvest pressure on adult hens.

What to do?

Some observers, notably Dave Rave, a retired DNR waterfowl manager, argue the national duck-hunting season limits of 60 days with six ducks allowed daily is too permissive, and that mallards and other ducks could better be protected by shortening the season to 45 days, or 30.

Another possibility, Arnold says, is to open Minnesota's regular duck season in October (rather than Sept. 21 this year, with a youth opener on Sept. 7-8), when hen and drake mallards can be more easily distinguished. Ending hunting in southern states in mid-January would also provide ducks valuable additional feeding and resting opportunities before returning north.

If Minnesota's regular duck season began in October, the state's early teal-hunting season could remain unchanged in September, because teal are relatively abundant. It's also possible, given the warmer autumns that climate change is producing, that blue-winged teal will stay in Minnesota longer in fall than they traditionally have, providing October hunting opportunities of these birds as well.

Another possibility is to change the state's current six-duck daily limit to, say, three, while removing species restrictions. Put another way, rather than worrying about whether in a six-bird limit a hunter can have only one pintail or two redheads, for example, he or she could have any mix of species and sexes, provided they kill only three ducks. (Other states are experimenting with similar ideas.)

Said Arnold:

"It's OK to harvest adult hens if we have sufficient breeding success. But with the habitat losses and drought that we've had in recent years, we haven't had that, and the last 10 years or so the continental mallard population has gone down.''