Predator Control to Boost Bird Numbers
The dark of night is pierced by a pair of headlights carving across the Ohio countryside and a truck rolled to a stop on a grassy strip between a corn field and a steep bluff that overlooked a river. Two men stepped out, and cut the dark of night with bright headlamps while their Walker coonhounds eagerly pressed against the doors of their dog boxes in the pickup bed. When the tailgate dropped and the doors opened the two dogs rushed headlong into the moonlight, and a few moments later the lead dog broke the calm with a loud, cascading bawl that echoed up and down the riverbanks. The hounds found a raccoon trail, and in short order they were barking treed. And while it may not seem that these raccoon hunters and their boisterous dogs are closely associated with waterfowl management, they’re soldiers on the front line of duck defense.
For years, waterfowl biologists have focused on improving and expanding nesting habitat for ducks and geese, and that’s been crucial to increasing waterfowl numbers across the U.S. and Canada. But aside from habitat conservation, the largest factor effecting nesting success of waterfowl are predator numbers and densities. Quite simply, if you want more birds, you’ll need fewer predators. And for that reason more and more waterfowl property managers are taking an active role in culling predators.
What's The Impact?
One of the first major studies regarding duck and goose predation was conducted by Alan Sargeant and Philip Arnold of the U.S. Fish and Wildlife Service in 1984 in the upper Midwest, and that research uncovered some key truths that have been central to our understanding of predator control in wetlands ever since. The results of that research project, which included data from 22 Waterfowl Production Areas, began to identify the species most responsible for waterfowl declines. Primarily, six mammal species—red fox, mink, raccoons, badgers, coyotes, and striped skunks—were responsible for the bulk of predation on nest sites, and research by the USFWS in 2003 backed those findings. Small mammalian predators significantly impact duck populations; Sargeant determined that just a single pair of breeding red foxes in a WPA could almost eliminate all successful duck nests in the area.
In fact, USFWS findings have indicated foxes are perhaps the most efficient and detrimental duck killers in most hunting areas, particularly because they have a tendency to remove every duck egg from a nest for consumption later. But raccoons were also common nest raiders, as were skunks and badgers. Coyotes, like foxes, consume adult birds, nestlings and eggs when given the opportunity. Minks attack hens, eat young birds and rob nests.
"Our contract people trap seven days a week," said Joel Brice of Delta Waterfowl, which has long been a proponent of predator management. Brice says consistent trapping of a specific area establishes a perimeter that will reduce predation on nests and eggs. Just be sure to check state regulations before getting started.
Direct predator control is the removal of a predator from your hunting area, either by trapping or hunting. For two of the primary waterfowl predators—foxes and coyotes—calling is a time-tested and effective proposition and, if done properly, it will help you knock back predator numbers. Raccoons also respond to calls, but hunting them with hounds is effective as well and they’re a primary target for many trappers. If you’re after mink, the most common—and effective—means of removal is trapping.
Indirect control methods—which don’t remove predators but rather limit their ability to effectively prey on waterfowl—can also be quite effective. In Sargeant’s original study of waterfowl predation, electric fences were being employed experimentally in WPAs throughout the Prairie Pothole Region, and while the tactic was still relatively new and untested, electric fences proved to be an effective deterrent against predation. The use of solar technology has allowed landowners to place electric fences in remote areas, and lightweight, portable electric fences can now be installed quickly and affordably. In a single afternoon a land manager can install a perimeter fence around their duck hole that provides the voltage needed to persuade even the hungriest predators to seek sustenance elsewhere. Removing these fences is fast and easy, and they can be stored through the winter if desired.
“It’s like being a shepherd," Brice said. The ultimate goal is not to kill all the wolves. The goal is to protect all of the sheep in the pasture.”
Perhaps the most effective indirect control method is habitat manipulation. The goal is simple—make your property as unproductive and uninviting to predators as possible by stacking the odds in the favor of nesting waterfowl. Duck boxes with baffles that turn away predators for example will help ducks avoid the teeth of foxes and coyotes. By mowing the area surrounding your impoundment, you’ll allow the birds to see approaching predators, and impoundments with steep edges and natural cover make it harder for predators to locate and approach nests.
A multi-pronged approach is the best defense against all predators, and while you may not be able to totally eliminate all small predators you can dramatically decrease losses.
Waterfowl habitat management revolves around creating habitats that are appealing to birds, and nothing is more appealing to ducks and geese than suitable habitat with few predators.