In recent years, one thing has become a common boogeyman for freelance duck hunters: large-scale private duck operations, particularly ones that utilize flooded corn and other hot crops. When the shooting is slow on public, many folks like to blame them for everything from messing up local flight patterns to short-stopping migrations. The truth, according to Mississippi State University Extension Waterfowl & Upland Gamebird Specialist James Calicutt, is often complicated and not completely understood.
Calicutt, an avid waterfowl hunter himself, is an expert in the Mississippi Flyway, which is one of the most hunted flyways in North America. In a recent interview with Split Reed, he discussed what we do—and don’t—know about the science of how flooded corn operations impact ducks along the Mississippi Flyway, which has seen a long-term decline in the number of mallards reaching historic wintering grounds in Arkansas and Mississippi.
So far, research shows that declines are most likely not caused by private duck operations’ management practices. Instead, one of the obvious main factors is out of our control: the weather. “In the past, when the Bootheel of Missouri and other places locked up with ice, it didn’t matter how much corn they had across that region, those birds were coming south,” says Calicutt. “With these mild winters, they’re just going to hang in the mid latitudes.”
One of the reasons this shows that weather—not flooded corn—is a driving factor of shorter migrations is waterfowl that don’t rely as much on weather, but that still eat grain, such as greenwing teal, pintails, and gadwall—are making their way south. Another reason that mallard numbers are in decline in southern areas likely has to do with habitat, which directly correlates to how many ducks are available to move and be hunted along a flyway.
Compared to overall habitat and weather conditions, Calicutt says flooded corn is much more difficult to quantify. “We are looking into it,” he says. “There’s a lot of interest in quantifying habitat on the landscape, but there are some things, like the private land side, that are harder to measure. We don’t have a good idea of how much standing flooded corn there is on average across most years.”
Calicutt says that it’s easier to understand the impacts that these kinds of private operations have on birds on smaller scales. “They can impact the local distributions of birds for sure,” he says. “Research shows that having high-energy food sources and low disturbance—or pressure—levels can draw birds and shift distributions, especially when it’s super cold out.”
That said, such impacts are not always simple or negative when it comes to public hunters. Though most folks can’t directly hunt these areas, they can still benefit from their presence in the area. “These private operations are an important source of habitat on the landscape, and not all of that is flooded standing corn. Many clubs include a mix of forested cover, moist-soil units, and agricultural fields,” he says. “Without those private areas, much of that flooded habitat might not be managed for ducks or even available at all. In that sense, they increase carrying capacity at the broader landscape scale, which includes public lands, and should, in theory, provide more ducks that can also use public areas.”
Another aspect of private operations that freelance hunters worry about is how they use ice eaters and pumps to delay freeze-outs. Again, Calicutt says it’s likely this can shift things locally, but less so on a flyway-level scale. However, as with flooded corn operations, there’s not a ton of hard data on this.
Calicutt says that he and his colleagues are working to improve their understanding of the impacts of flooded corn because “everyone keeps talking and asking about it.” For instance, satellite imagery may soon help researchers quantify standing corn on the landscape.
“We will continue to refine our understanding of how flooded standing corn influences duck distribution and migration, but we already know that the breeding grounds need help and that local landscapes in many places have likely declined in quality,” he adds. “To make both public and private lands hold more ducks and provide more opportunity for harvest, we need to address all of those pieces together: breeding habitat, local habitat quality, and how we manage food and water on the wintering grounds.”