"A heavy snowstorm makes ducks go crazy," says Al Aufforth of North Dakota, a professor of wildlife biology at Minot State University–Bottineau and a lifelong duck hunter. "They come off the refuge en masse and feed all day. They work in big swirls, sometimes numbering thousands of birds, and when they come in, it looks like a wall of mallards driving through the snow.
"By the late season, most shallow potholes are frozen," Aufforth continues, "but the ducks will still be here if the reservoir on the national wildlife refuge is open. Typically, these birds fly out to feed in stubble fields [wheat or peas] in the morning and afternoon, but a sudden snowstorm will change this pattern. When the snow hits, ducks are frantic to gorge on grain, so they feed all day. Then, typically, they leave for parts south. So from a hunter's perspective, this opportunity is short, but also very sweet."
Aufforth decides where to hunt by watching ducks fly out of the refuge. "You have to be there when that first flight comes off," he says. "All ducks that follow will usually fly the same route, and the trick is to get beneath them. You don't have to be in the exact field where they're going, just under the flyway."
Instead of digging pits or setting out layout blinds, Aufforth and his hunting partners simply lie in the snow. "We wear white coveralls, gloves, ski masks, and watch caps," he says. "And we wear all the clothes we can get on underneath our coveralls. This style of hunting is cold. I've had my shotgun safety freeze up many times."
Aufforth uses a small spread—two dozen full-body field mallards and seven full-body Canada goose decoys. He sets these in a J formation with the mallards in the shank of the J, pointed upwind. He places the Canada geese in the turn of the J. He says the ducks usually want to land inside the cup of this design, so this is where he lays out. He simply reclines in the snow, feet pointed downwind, and he builds a small snow fort approximately two feet high around him. "This low wall of snow hides me from incoming birds," he explains.
Then he watches and listens for ducks flying close. He calls very little, since sound doesn't travel well in the snow and wind.
"If the snow is really coming down," Aufforth stresses, "you need to continuously sweep your decoys clean. You want them to be dark and to stand out against the white snow. And if the ducks change their flight lane, you have to be willing to change locations in a hurry. Ducks can't see very far in the snow, so you have to go to them instead of hoping they'll find you."
In more temperate regions, heavy winter rains can cause a sudden shift in ducks' feeding locations. For instance, Avery Outdoors pro staffer Stuart McCullough of Los Banos, California, says a sudden deluge can flood extensive new areas in the grasslands of the Central Valley. When this happens, ducks move immediately to this fresh water and new food source. Hunters who follow them can enjoy excellent shooting.
"When a hard rain comes, the rivers will rise quickly and flood new sloughs and pastureland," McCullough says. "If this happens late in the season, it invigorates our hunting. Ducks that have become patterned to sit on refuges and private clubs will scatter out into these newly flooded areas. They do this as soon as the rain stops or even when it's slowing down. Hunters who understand this and have the know-how and equipment to take advantage of the situation can have a great hunt."
McCullough says good scouting is necessary to locate areas where the birds are moving, and in many cases layout blinds are the key to success. "In this area, much of the flooding occurs in wide-open fields where hiding is difficult. But with the Finisher blinds, you can set up just about anywhere on dry ground. Just set them out at water's edge, add some natural cover, toss out your decoys, and you're ready to hunt.
"So this is a simple matter of scouting after a heavy rain, finding where the ducks are working, and then setting up quickly to take advantage of this new opportunity," McCullough says. "It's a run-and-gun style of hunting that's totally dependent on being in the right place at the right time."