By Wade Bourne
Biology plays a bigger role in duck hunting than most hunters realize. Duck behavior is governed by instincts such as feeding, mating, and surviving. In winter, for example, ducks spend much of their time seeking mates for the spring breeding season and building energy reserves for the coming northbound migration.
According to DU chief scientist Dale Humburg, 90 percent of mallards are already paired with mates by late January. When these birds pair up, they isolate themselves from other ducks.
Buckbrush swamps, flooded timber, willow sloughs, tule marshes, and similar places where cover is thick are ideal hideaways.
"Pairs don't like competition, so they isolate themselves so they can be alone," Humburg says. "Here the paired ducks—especially the hens—increase consumption of invertebrates and other protein-rich foods to complete the winter molt and prepare for the rigors of egg laying."
Unpaired mallards, on the other hand, typically gather in large flocks in wide-open wetlands. By gathering in open areas, displaying males can be more visible and attractive to available hens. Also, these unpaired ducks are focusing more on carbohydrate-rich foods such as corn and rice to build fat reserves for their upcoming migration north.
The ducks know instinctively when shallow feeding areas open up after a hard freeze. A marsh that thaws in the morning can be covered with birds that afternoon.
Understanding the different behaviors of paired and unpaired ducks gives hunters two basic choices in terms of late-season hunting spots and tactics. Option one is to target the sheltered habitats with heavy cover where the isolated pairs are hiding. This requires mobility and extensive scouting to find ducks that really don't want to be seen. Once a likely spot is located, hunters should use subtle tactics such as small spreads, limited calling, and jerk strings to coax these shy birds in.
Option two is to set up in flooded fields and shallow wetlands to mimic a concentration of feeding ducks. In this case, more dynamic tactics are called for—including large, highly visible decoy spreads, aggressive calling, and motion.
"In the fields, it's all about getting the ducks' attention," Humburg says. "Unpaired birds are anxious for company, and they're accustomed to finding it in wide-open areas. There are typically more drakes in these open-field concentrations. For them, it's a see-and-be-seen situation. So hunters should mimic nature by setting out a lot of decoys in a busy flyway and being bolder in their attempts to lure in passing flocks."
There are other factors that affect hunting success in the late season. A hard freeze can push ducks from marshes and flooded fields to big lakes and rivers. Many of these birds will feed in dry fields and return to big water to loaf and preen. Conversely, a sudden thaw can move birds from open water back to shallow feeding areas. This movement can occur quickly. The ducks know instinctively when shallow feeding areas open up after a hard freeze. A marsh that thaws in the morning can be covered with birds that afternoon.
Watch for Reverse Migrations
Yet another late-season opportunity comes in the form of a "reverse migration." As spring migration draws near, ducks begin to anticipate returning north. When a strong southerly wind blows, some birds invariably hitch a ride on it back up the flyway. They don't return to their breeding grounds in one big jump. Instead, they fly northward in increments—from Mississippi to Missouri, for example—then hang around for a few days until a new southerly wind kicks up.
Hunters should watch the weather map during the late season, and if a strong warm front approaches, they should head to their blinds.