By Paul Wait
An abundance of quality habitat for breeding waterfowl is essential to have strong duck populations. It’s an indisputable fact.
However, the days of “conserve it and they will come” are over.
On today’s landscape, habitat conservation efforts alone simply are not enough to deliver consistently high duck populations. Following a century of wetland drainage and sweeping land-use changes across the continent’s key waterfowl breeding range, we’re no longer working with a large enough base of wetlands and nesting cover necessary to send the historically bountiful flights of mallards, pintails, teal, canvasbacks and scores of other ducks coursing south on cool autumn winds all across North America.
Sure, in years when the Prairie Pothole Region is exceedingly wet, duck populations respond and production is high. As evidenced by recent drought conditions in 2020 and 2021, a wet prairie is far from certain. Even under ideal conditions, the landscape is not producing as many ducks as it could.
For most of the past 100 years — back to the earliest days of waterfowl management in the United States and Canada — conservation leaders have focused almost exclusively on conserving habitat. Billions of dollars from duck stamp revenues, Farm Bill programs such as the Conservation Reserve Program and massive shares of private philanthropy have protected millions of acres of breeding waterfowl habitat. Delta Waterfowl has certainly played a key role in habitat conservation through voluntary, incentive-based programs such as Working Wetlands in the United States and GROW and Alternative Land Use Services in Canada, in addition to key land-use policy initiatives. Without question, Delta will always fight tirelessly to conserve as many acres of breeding waterfowl habitat as possible on the prairies.
Sadly, much of the waterfowl habitat we’ve paid handsomely to conserve simply is not producing very many ducks.
“Conservation-minded waterfowl hunters have already made a significant investment in habitat, so we’d like to take it the rest of the way to achieve the duck production goal of habitat conservation,” said Joel Brice, chief conservation officer for Delta Waterfowl.
Delta Waterfowl believes that the number of ducks — not wetland and grassland acres — should be the measuring stick of waterfowl management success. As The Duck Hunters Organization, our mission is clear: To produce ducks and ensure the future of waterfowl hunting.
By launching the Million Duck Campaign in July, Delta Waterfowl is putting forward an innovative, complementary strategy to maximize duck production on the existing waterfowl habitat in North America. Through the use of Hen House nesting structures and strategic deployment of Predator Management, Delta will dramatically boost duck production on the existing breeding ground habitat.
“We’re going to add 1 million ducks to the fall flight every year, forever,” said Dr. Scott Petrie, Delta’s chief executive officer.
Realities of the Prairie Breeding Grounds
In spite of our best efforts, we cannot conserve all of the breeding waterfowl habitat in North America. Buying land outright to set aside for wildlife is prohibitively expensive, and only so much money is available to obtain habitat easements.
The PPR, which stretches from northern Iowa and western Minnesota, through the Dakotas and eastern Montana, and up into Manitoba, Saskatchewan and Alberta, is a working agricultural landscape. A substantial portion of North America’s grain crops such as wheat, barley, soybeans and corn are grown in the region where 50 to 70 percent of the continent’s ducks also hatch.
“We’ve done a fairly good job of protecting wetland habitat in the Dakotas,” said Dr. Frank Rohwer, Delta’s president and chief scientist. “But in prairie Canada, wetland losses are continuing at an alarming rate. While easements keep wetlands from being drained, they don’t do anything to increase duck production. A lot of prairie wetlands that we’ve saved from drainage could be producing ducks, but they are not making many ducks because of an overabundance of predators.”
Changes in land use and farming practices over the past century have resulted in sweeping changes for nesting ducks. In addition to wetland drainage, the predator-prey balance has shifted dramatically, Rohwer said.
Prairie grasslands were settled and converted to grain crops and ranches, and top mammalian predators such as wolves and mountain lions were displaced. New, smaller predators such as raccoons and skunks — animals that prefer to hunt for food near wetlands — began to thrive in the agricultural landscape.
“These fragmented wetland habitats on the prairie attract ducks, but they also attract high numbers of predators,” Rohwer said. “The result is most nests are destroyed by predators, and very few ducks hatch in these habitats.”
The collapse of fur trapping across North America has added to the imbalance. In many areas, raccoons, skunks and other duck nest predator populations now grow unchecked.
“Predators are a huge problem for ducks,” Brice said. “Nobody’s out trapping them in these landscapes except Delta’s Predator Management trappers. Right now, we’re depending on occasional great years when the prairies are very wet to maintain our duck populations. We’ll have a lot better success if we manage nest predation by deploying Hen Houses and Predator Management on a much larger scale.”
Predator Management in Action
Delta Waterfowl has studied Predator Management since 1994. Dozens of researchers have conducted scientific examinations of the technique in different habitats and nesting conditions in the PPR. Study after study has shown that Predator Management cost-effectively boosts duck production. Delta’s research continues today, but now has shifted toward refining the efficiency of delivering the program to produce even more ducks.
Mike Buxton, senior waterfowl programs manager for Delta Waterfowl, selects the Predator Management sites for The Duck Hunters Organization and works with contractors to deliver duck production.
A good Predator Management site — one where Delta’s program can have the most impact — has a lot of wetlands and attracts high densities of breeding ducks. Typically, that means at least 60 pairs of ducks per square mile, Buxton said. The other criteria on the U.S. prairie is that an area has a low density of grass cover, typically less than 15 percent.
“We know those are areas with the poorest hatch rates because of nest predation,” he said.
Buxton explains that it typically takes 40 percent nesting cover across a larger landscape to achieve a break-even nest success rate of 15 to 20 percent for ducks. Generally, the less cover on a landscape, the easier it becomes for mammalian predators such as raccoons, skunks and others to find duck nests.
Most areas of the prairie breeding grounds simply do not have that high of a percentage of idle grass cover.
In Canada, Buxton looks for areas that attract high numbers of breeding ducks that are void of pasture lands that make summer trapping difficult, but still have some natural nesting cover such as wetland margins or other grass easements.
“There’s very little idle grass on the Canadian prairie,” Buxton said. “Almost all of it is being used for farming or ranching.”
Delta’s Predator Management is adaptable to different landscapes. In Canada, a block trapping approach often works best. Essentially, the goal is to catch nest predators on a perimeter before they can begin hunting for duck nests. In the United States, Delta also uses hotspot trapping. Rather than blanketing a perimeter, the hotspot approach is designed to catch predators right next to and in the cover where ducks are nesting.
In all deployment strategies, Delta’s Predator Management is designed to dramatically boost the number of duck nests that hatch.
To understand the impact of Predator Management, Buxton explained a township block trapping scenario in North Dakota. All of the following is based on three decades of research, including Buxton’s own studies and years of experience as a waterfowl biologist.
The trapper sets traps throughout a township-sized block, which is 36 square miles. This particular block has abundant small wetlands, but is intensely farmed, with only about 15 percent nesting cover on the landscape.
The block attracts 80 pairs of ducks per square mile, which equals 2,880 breeding pairs of mallards, pintails, blue-winged teal, gadwalls, shovelers and a smattering of other species. Studies have shown that Predator Management on this landscape will boost nest success to 34 percent. That means slightly more than one in three nests will hatch. Without Delta’s Predator Management, nest success would drop to 5 to 15 percent.
Let’s take the math a step farther. Many hens that lose their first nest attempt will renest, and with fewer raccoons and skunks to find and eat their eggs, they are successful in their next attempt. In fact, research reveals that 52.8 percent of the ducks — more than half — will hatch a nest on our Predator Management block.
Buxton calls the percentage of nesting ducks that hatch a nest “hen success.” The average nest hatches nine eggs, and half of those ducklings will survive to fledge (fly). So, Delta’s Predator Management site produces 6,843 ducks.
“The best way to maximize duck production is to improve nest success and hen success,” Buxton said. “We know that on many of these areas, nest success is being hurt by predation, and many areas are not living up to their potential. We know that Predator Management can help Waterfowl Production Areas and CRP lands operate at their fullest potential to produce ducks.”
Hen Houses Reduce Predation
Hen Houses, which Delta has been using since 1991 to produce ducks, are innovative nest structures favored by mallards.
Just like Predator Management, Delta’s Hen House program is backed by decades of research. As a master’s degree student through Mississippi State University in 2001-2002, Matt Chouinard studied Hen House usage and placement in wetlands near Delta’s Minnedosa Field Station in southern Manitoba. He returned to Delta Waterfowl in 2007 as a biologist to manage the organization’s Hen House program in Minnesota.
Delta’s research has shown that Hen House usage rates are highest when one or two structures are placed on a small wetland. Delta has also refined the best nesting materials for Hen Houses, discovering that usage rates are highest with a durable flax straw.
The nest structures are installed on a pole, so the cylinder rests a few feet over the water positioned out from the edge of the emergent weeds ringing the wetland. Hen Houses keep the nesting mallard and her eggs out of reach from most mammalian predators.
They work exceptionally well, with usage rates typically ranging from 60 to 80 percent. Nest success is up to 12 times that of mallards nesting on the ground in nearby grass. Hens are less susceptible to predation, and duckling survival is likely also boosted by Hen Houses because the freshly hatched ducklings can just plop directly into the water below when it’s time to leave the nest. Ducklings hatched in a nest bowl on the ground are more vulnerable to predators during their first hours of life and their initial march to find water.
Chouinard manages Delta’s fleet of nearly 10,000 Hen Houses that have been strategically placed throughout the PPR and other key duck breeding areas.
“To have the most impact, the best areas to deploy Hen Houses have a lot of wetlands that attract high densities of mallard pairs, but where nesting cover is sparse,” he said. “We look for those areas when choosing sites for Hen Houses.”
Hen Houses are deployed in clusters — often called Supersites — for efficiency of installation and yearly maintenance, Chouinard explained.
Hen Houses, which have an average lifespan of 10 years, are the most cost-effective tool to reduce the impact of predators on nesting mallards and send a lot more of North America’s most popular duck winging south every autumn.
Delta’s Million Duck Campaign Promise
The primary goal of the Million Duck Campaign is to maximize duck production.
Delta Waterfowl has embarked on a bold, ambitious $250 million fundraising initiative to create an endowment fund that will deliver 1 million ducks annually to the fall flight.
The Duck Hunters Organization will scale up its proven duck production programs to put more ducks into all four flyways. Strategic installation of Hen Houses will take the mallard-producing program to 110,884 structures across the PPR, while also scaling Predator Management to 366 sites. The result is the annual production of 1,000,660 ducks.
“The Million Duck Campaign will support Delta’s work across all four critically important pillars: habitat conservation, research and education, HunteR3 and of course, duck production,” Petrie said. “We want to lead waterfowl management into a new era where we measure success by our contributions to the fall flight.”
The best way to achieve the goal is to maximize duck production on our existing habitat.
“We’ve become so ingrained that habitat protection is the only way to do waterfowl conservation,” Rohwer said. “Habitat protection without focusing on duck production is pointless. It seems kind of crazy not to spend money on duck production. Putting all of our duck dollars only into habitat is like a business building a factory and then not producing very much in it. Delta Waterfowl has the programs to produce ducks, and it’s time to put them to work.”
Paul Wait is senior manager of communications for Delta Waterfowl.