Delta Waterfowl’s Response To DU’s FAQs on Predator Management
Posted on 09/30/2003
Delta Waterfowl welcomes the opportunity to respond to Ducks Unlimited’s questions about predator management.
First, Delta would like to go on record as supporting DU, which over the years has conserved 10 million acres of habitat in all 50 states, all Canadian provinces and areas of Mexico. Habitat is the first and most basic ingredient in the recipe for making ducks, and we applaud everyone in the business of putting habitat on the landscape.
We do not, however, believe habitat is the only ingredient necessary to sustain healthy duck populations, nor do we feel predator management conflicts with or detracts from waterfowl management’s overall mission. Rather, we believe our efforts complement the goals of management.
Delta believes duck hunters have a right to expect that the dollars they spend on waterfowl management are resulting in increased duck production, and we think most sportsmen would agree. Nesting ducks require very specific habitats, and where waterfowl management cannot provide sufficient habitat, management tools like those promoted by Delta must be incorporated.
Delta encourages DU to continue to conserve habitat continent-wide, but wants sportsmen to understand that in many cases habitat acquisition is just the beginning. Delta’s management tools pick up where DU’s habitat efforts leave off.
With that in mind, here are our responses to the questions raised by DU.
Q: Other than a “slight” decline because of drought in 2001 and 2002, aren’t duck populations healthy? Doesn’t the 69 percent increase in duck numbers between 1994 and 1999 prove that the habitat is all in place, and all we need is water?
A: Delta Waterfowl did not see the 31 percent decline in mallard numbers in 2000, 2001 and 2002 as “slight”, and we don’t believe hunters did either. Delta was concerned about the precipitous drop because—contrary to DU’s response—it began at a time when wetland conditions on the breeding grounds were still reasonably good.
In fact, the May pond count was higher in 2001 than it was in either 1998 or 2000, and only 10 percent below what it was in 2003. At Delta, we saw the three-year contraction in spring breeding numbers as a sympton of a larger problem.
What problem? “The single most important factor depressing current waterfowl populations is the low success rate of nesting hens that is a result of severe predation rates on the prairies. In many areas of Canada, this factor is thought to be even more significant than the historical loss of wetlands.”
The above statement is as true today as when it appeared in Ducks Unlimited Magazine in 1994. The quote was attributed to Dr. Bruce Batt, who at the time was with DU’s Institute for Wetland and Waterfowl Research (IWWR) and currently serves as DU’s Chief Biologist.
In a recently released study on mallards, Steven Hoekman reported that predation was a far more significant factor inhibiting population growth than wetland conditions.
DU suggests the 69 percent increase in duck numbers between 1994 and 1999 shows that the habitat necessary to produce ducks is in place, just waiting for Mother Nature to “add water”. DU’s own research says otherwise.
Between 1993 and 2000—a time when the continental duck population was soaring thanks for a prolonged wet spell—DU’s IWWR conducted an exhaustive research project across prairie Canada. The final results of that nine-year study show that at 19 of 27 sites, the percentage of hens that died during the nesting season exceeded the number that successfully hatched a single duckling. Nest success for mallards exceeded the population-expanding minimum at only three of 27 sites (most scientists say 18 percent is the minimum maintenance level for mallards).
In 1998 DU scientists reported, “…predation negatively influenced production at all sites”. The Assessment also said, “Although they imply greater uncertainty about habitat management prescriptions, the uniformly poor results across the Canadian prairies offer important food for thought.”
Q: What’s the most important thing we can do to help ensure healthy duck populations for the long term?
A: Delta Waterfowl agrees on the importance of preserving habitat for the long-term benefit of ducks. But Delta believes waterfowl management can conserve habitat and actively manage for healthy duck populations.
Delta understands the importance of habitat, and has been fighting to protect habitats critical for duck production since its inception. It was Al Hochbaum, Delta’s first scientific director, who in the 1940s identified the importance of seasonal and temporary wetlands for nesting ducks—one of the most important discoveries in the history of waterfowl science.
When some of the best of those small wetlands were threated by an action by South Dakota’s Natural Resources Conservation Service (NRCS) in the late 1990s, Delta was front-and-center in the fight to protect small wetlands. Delta also has been actively involved in the fight to save the wetland-protection provisions of the Clean Water Act.
Research conducted by Ron Reynolds of the US Fish and Wildlife Service showed that ducks achieve population-expanding nest success only where 40 percent of the landscape has grassy nesting cover. When large blocks of native prairie in North and South Dakota were threatened, Delta led the fight to save them.
But as much as Delta understands the importance of habitat, we also recognize its limitations. Putting 40 percent of the entire prairie pothole region into grass nesting cover is socially, politically and economically unrelistic. Where the landscape falls short of the 40 percent habitat threshold, other management tools are necessary.
Predator management and artificial nesting structures (Hen Houses) are two of those tools. Where habitat alone is not enough to impact duck production, Delta wants to put those tools to work raising more ducks.
Q: But predators have to be removed every year. Doesn’t that make predator management too expensive?
A: It’s true predators must be removed annually, but it’s misleading to suggest that habitat conservation has a fixed cost. For example, refuge managers say controlling noxious weeds is more expensive than managing predators.
Some of the management tools endorsed by DU—electronic predator exclosures, nesting islands/ peninsulas and dense nesting cover—are extremely expensive compared to predator management, and also require annual maintenance. Predator exclosures and islands, for example, must be trapped annually to remove predators that took up residence during the winter months.
Predator management is relatively inexpensive, and science has demonstrated that controlling predators results in huge gains in nest success. Since Delta launched its predator management program in 1994, we have consistently increased nest success two- to three-fold. In the most recent nesting season, one of our predator sites had 80 percent nest success, which means 80 percent of all the duck nests in a 36-square-mile block were successful.
Before the population can increase, breeding hens must be successful. Nest success has been extremely high on Delta’s predator blocks, and we have the science to prove it.
Q: Isn’t predator management diverting dollars from habitat conservation?
A: We’d contend that a disturbingly high percentage of the dollars spent on habitat conservation have been dollars diverted from duck production.
A closer look at North American Wetlands Conservation Act (NAWCA) expenditures shows that less than 9 percent of all the NAWCA dollars spent in the US were spent in the pothole states of North Dakota, South Dakota and Montana combined. In recent years those three states have produced over half the ducks originating in the PPR, which contributes 60 to 75 percent of the continent’s total ducks.
Delta recognizes the importance of wintering habitat, but most scientists agree low production—not a shortage of wintering habitat—is the major factor inhibiting growth of the duck population.
There are, however, volumes of scientific evidence showing that predation on the prairie breeding grounds is inhibiting the growth of the duck population.
Q: DU says it doesn’t trap furbearers because anti-hunters might use trapping as an argument against hunting. Is Delta concerned about the anti-hunters?
A: For the record, DU does trap furbearers. According to an article in the fall 2003 issue of Cattails, the official publication of Minnesota Ducks Unlimited, DU hired dozens of trappers to remove beavers from wild rice lakes in Minnesota last spring.
Delta supports the use of trappers to restore degraded habits in Minnesota and elsewhere. We do not, however, understand DU’s objection to Delta using trapping to restore a semblance of natural balance on the breeding grounds.
Is DU saying trapping dam-building beavers is acceptable but trapping nest-destroying predators is not? Where does DU stand on trapping nutria and muskrats?
DU says trapping “plays directly into the hands of those who are anti-trapping or anti-hunting, and it could be used by anti-hunters to turn more people against hunting.”
Delta doesn’t believe sportsmen should allow the animal-rights and anti-hunting community—who contribute nothing to wildlife conservation—to dictate sound management policies.
At Delta Waterfowl, everything we do is based on whether it’s the right thing to do for ducks and duck hunters. Our actions are directed by sound scientific research.
As for the general public, research conducted nationwide by Terry A. Messmer of Utah State University showed that 58.9 percent of survey respondents supported controlling skunks, raccoons and foxes to improve duck nest success, and another 21.2 percent said they were neutral. Only 12.9 percent of those polled opposed controlling predator numbers for the benefit of nesting ducks.
Q: What if the anti-hunters point out that predators are being trapped when the young are still dependent on their parents?
A: That’s the same argument the anti-hunters used in Ontario when they successfully banned spring bear hunting several years ago. When those same anti-hunters tried to ban spring bear hunting in Manitoba, Delta led the fight to defeat them.
We think it’s time to set aside the rhetoric and emotional arguments, and let science chart the course of waterfowl management.
Q: Isn’t this debate creating a divide within the waterfowl hunting and conservation community?
A: Delta sees a dialog between conservation organizations as healthy, not divisive. Delta has never opposed DU’s conservation efforts, nor have we ever raised this issue in a divisive way. On the other hand, we have been compelled to defend our research and management tools when they’ve been challenged, which is exactly what we have been forced to do here.
Delta doesn’t believe predator management and habitat restoration are mutually exclusive. We totally support DU, the Nature Conservancy, the Audubon Society and other organizations working to preserve critical habitats across the continent.
But Delta also believes duck hunters have a right to expect an increase in duck production in return for the hundreds of millions of dollars they contribute to waterfowl conservation.
Science has shown that two of the best tools for increasing waterfowl populations are predator management and artificial nest structures, like Delta’s Hen Houses. DU’s own IWWR Assessment confirmed the effectiveness of Hen Houses in 1998. According DU biologists, “…with the exception of nest structures, nest success was low in all habitats at all four Assessment sites.”
Q: Does anyone else agree with Delta’s point of view on predator management?
A: Let’s be honest, the Mississippi Flyway states weren’t even unanimous in their rejection of predator management: Arkansas and Louisiana sponsored Delta predator management sites this spring. No other flyway has adopted a position against predator management.
Supporters of predator management are everywhere. The US Fish and Wildlife Service is Delta’s willing partner in a number of predator management efforts on the breeding grounds. The North American Waterfowl Federation (a coalition of state waterfowl organizations) in 1999 endorsed predator management. Even the Audubon Society and the Nature Conservancy recognize the impact of predators and manage predators on their properties.
Predator management occurs even on DU-funded projects. One good example is Kellys Slough National Wildlife Refuge, a $4 million project in northeastern North Dakota. During the first three years Kellys Slough was in existence, nest draggers were unable to locate a single successful nest. Only when a trapper was contracted did Kellys Slough begin producing ducks.
Q: What was DU’s response when the Fish and Wildlife Service trapped Kellys Slough National Wildlife Refuge?
A: According to a question-and-answer sheet distributed by DU Senior Communcations Coordinator Eric Keszler, “Because this (Kellys Slough) is a relatively small area surrounded by mostly cropland, the Fish and Wildlife Service found it necessary to conduct predator control. DU supports that decision.”
That’s exactly what Delta has been saying for years. Most of the drift prairie of eastern North Dakota meets the DU-described criteria—small patches of nesting cover surrounded by large expanses of cropland. Most of prairie Canada falls into the same category. Fifty percent of the ducks nesting in North Dakota settle in the drift prairie, where—as was the case at Kellys Slough—they have little or no chance of being successful because 90 percent of the nests are destroyed by predators.
Waterfowl management will never have the financial resources (or the acceptance from agricultural communities) to restore even a portion of the nesting cover or wetlands lost to agriculture during the last 150 years. Predator management and nest structures are two effective tools to address low duck production on fragmented landscapes like the drift prairie.
Q: Predator management wouldn’t help declining scaup and pintail numbers, so doesn’t that prove predator management isn’t worth the effort?
A: If we could put the shoe on the other foot for a moment, DU’s habitat-conservation efforts of the last 70 years haven’t been able to break the freefall of scaup and pintail numbers either. Does that mean we should abandon habitat conservation? Certainly not.
Scaup and pintails face special challenges that only recently were uncovered by scientists. In fact, Delta was responsible for much of the research that idenfitied those challenges, and now we’re following that science in an effort to overcome them.
For instance, Delta is working diligently for Alternate Land Use Services (ALUS), a CRP-like grassland program for Canada. We’ve also been actively involved in the battle to protect some of the best pintail habitat on the continent, the native prairie of the Missouri Coteau in North and South Dakota. And we’ve increased pintail nest success dramatically on our predator blocks.
The pintail is a classic example of how ducks can benefit from cooperation among agencies and organizations with different missions. At Delta, we don’t see our efforts as being in conflict with DU’s goals, but rather as complementing them for the benefit of ducks and duck hunters.
Delta Waterfowl strongly supports Ducks Unlimited’s efforts to conserve habitat. Habitat is to ducks what flour is to a loaf of bread—it’s the first and most important ingredient in the recipe.
But it takes more than flour to make a loaf of bread, and it takes more than scattered habitat projects to raise ducks on severely altered landscapes. Where waterfowl management doesn’t have the resources to put adequate nesting habitat on the ground, science has shown that other management tools must be incorporated if we hope to sustain viable duck populations.
Delta supports the efforts of DU, the Fish and Wildlife Service, state agencies and waterfowl associations using a myriad of tools for one common cause. Hopefully all of us—working together and following the science—will be able to achieve the ultimate goal of securing a bright future for the continental duck population.