Respected Waterfowl Scientists Say Predator Management Critical
Posted on 05/30/2007
JAMESTOWN, N.D. - A group of retired scientists says land-use changes on the North American breeding grounds may force waterfowl managers to choose between controlling predators and watching duck populations plummet.
One reason for their concern, the experts say, is an ethanol-fueled demand for corn that's likely to result in a reduction of grass nesting cover across the U.S. side of the region.
Arnold Kruse, John Lokemoen, Ray Greenwood and Alan Sargeant were part of the prestigious team of researchers who literally wrote the book on North America's "duck factory" while working at the Northern Prairie Wildlife Research Center (NPWRC) in Jamestown, North Dakota. The NPWRC was formed in 1965 when U.S. Fish and Wildlife Service biologist Harvey Nelson assembled an all-star team of researchers charged with unraveling the mysteries of the prairie ecosystem.
One of the things they learned is that mammalian predators take a big bite out of duck production. In an interview that appears in the current issue of Delta Waterfowl magazine, they expressed concern about the impact of predators on populations of ducks and other ground-nesting birds.
"Our research showed there's a big problem with predators out there," says Sargeant. "The problem has not gone away. There are still lots of things eating lots of other things out there."
Since 1985, millions of acres of CRP cover have buffered hens from nest-raiding predators like fox, raccoons and skunks. Research conducted by the U.S. Fish and Wildlife Service showed that CRP added 2 million ducks to the fall flight each year since 1992.
Unfortunately North Dakota, South Dakota and Montana, three states that since 1994 have produced as many ducks as prairie Canada, are expected to lose a minimum of 930,000 acres of CRP by 2010, more if the ethanol-driven demand keeps corn prices at current levels. An additional 434,000 acres of land was converted from native prairie to cropland between 2002 and 2006.
"CRP has kind of lulled everyone (into a false sense of security)," Kruse says. "If we lose this CRP, the predator thing is really going to stare us in the face. Corn's gone up a dollar a bushel over the last year. That means we're going to lose a lot of CRP nesting cover."
"We've been blessed with CRP for quite a few years, but now what are we going to do for ducks?" asks Sargeant, who is considered one of the continent's foremost authorities on the impact of fox and other predators on nesting ducks. "Either you're going to do intensive management or ducks are going to take it in the shorts."
Countless studies have confirmed that predation is the cause for most nest failures, but waterfowl managers have shied away from predator management because it is viewed as politically incorrect. Greenwood says concerns about predator management as a tool are nothing new.
"Predator management was on the outs before us too," Greenwood says. "Before we came along, it was believed predators only took the sick and incompetent birds. We found that wasn't the case, that predators are a very important part of the ecosystem, preying on vulnerable breeding hens and ducklings. We kept the pot stirred with new findings and new research. But it's really not in vogue to kill, so I think the emphasis on predators has slid."
"It's always difficult when you want to kill one animal to defend another," admits Lokemoen. "It's easier to do something like buy potholes and plant cover. Those are good things, but maybe we have to take the next step."
"Predator management works," says Sargeant. "You get rid of predators and things start to happen. Yes, it costs money to manage predators, but it costs money to pay taxes, it costs money to burn, it costs money to start your truck and drive out to see if your habitat is in place and your fences are up."
All expressed frustration that their findings on the impact of predators haven't been put to work on a large scale, saying intensive-management practices like predator removal are a cost-effective way to supplement habitat.
"If you're going to pump money into habitat, crank it against what you're going to get out if it (in terms of ducks)," Sargeant says. "The fact is, if you want to make the habitat work, you better think about some teeth."
When asked how important it is to manage predators, Greenwood answered: "How many ducks do you want? Do you just want to see them, or do you want some to shoot? If you just want to see them, you don't have to do anything."
Delta Waterfowl has been managing predators in North Dakota since the early 1990s, and this year expanded its predator-management research program into Saskatchewan and South Dakota.