July 30, 2012
Last season may have been one to remember, not only because a record number of ducks flew south, but because we may not see another season like it for a long time. Thanks to a looming decline in critical nesting habitat, ducks are facing a grim future.
North Dakota has already lost 3,100-square miles of nesting cover since 1999 — a trend that will likely worsen. Nearly 800,000 acres enrolled in the Conservation Reserve Program in that state, the heart of the duck factory, are set to expire this fall. Congress is also considering major cuts to various agriculture programs, including the CRP, which has played a significant role in duck production since its inception in 1985.
An estimated 2.5 million additional ducks are produced each year as a direct result of CRP. If some lawmakers get their way the program may be capped at 25 or even 20 million acres, down from the current cap of 32 million acres, says Delta Waterfowl's John Devney. On top of that, commodity prices are skyrocketing; many farmers are choosing not to re-enroll land that was protected by CRP.
"When you look at the average payments for CRP compared to the cash rental rates, it's not hard to figure out what landowners will do when they have a choice of enrolling their land in CRP or renting it out to a farmer," says Devney.
That's why the future of duck management may partly lie in controlling predator populations. As the total acreage of high-quality nesting habitat dwindles, there's no question nest predation by skunks, raccoons and other terrestrial mammals will have an even larger impact on duck production. Trapping could be one solution. Delta has been involved in predator management research since the mid-1990s when scientists attempted to answer a basic question: Will removing predators from nesting areas have a positive effect on duck production? The answer is a resounding "yes," particularly in areas with poor nesting cover.
One study in Canada found nest success was just 3 percent on untrapped areas compared to 31.5 percent on trapped areas. Another study found positive results in North Dakota, as well.
Nest success was just 16.7 percent on untrapped land, but 32.6 percent in areas where trappers removed high numbers of mammalian predators.
Devney says predator management may not necessarily be the only solution if current trends in CRP losses continue, but it will certainly be a viable solution and one that may be a necessary tool if the loss of nesting habitat continues. Roger Hollevoet, U.S. Fish and Wildlife Service biologist and refuge complex manager, agrees.
"Right now, I'm not even thinking about it. We have lots of water, good grass and low predator numbers thanks, in part, to a mange outbreak," says Hollevoet, who oversees 250 waterfowl production areas in North Dakota. "If the region continues to lose suitable habitat, then I think predator management could be a useful tool in waterfowl recruitment."
But predator management isn't free. Nor is it cheap. One study by Delta suggested that trapping efforts cost as much as $20 per duck produced. Devney, however, looks at it from a different angle: the numbers work out to just $1.50 per acre. He says it's not unreasonable to institute predator management efforts on as many as 175 treatment areas that span 36-square miles each for a total cost of about $6 million per year. That may seem like a hefty price tag, but it's a fraction of the total amount spent on waterfowl conservation through private, state and federal conservation efforts.
"Ducks are expensive, no matter how they are produced," insists Devney. "I don't know what the cost per duck is for other treatments, but I bet you would be hard-pressed to find a cheaper cost-per-duck treatment than predator management."
He's right. A 2007 study authored by Ben Rashford and Richard Adams found that cropland retirement programs produced one duck per $1,111 spent while predator control costs $66 per duck produced. It's substantially more than the $20 per duck suggested in the Delta study, but it's a bargain compared to the money spent on various conservation programs.
Not everyone likes the idea of increased predator management efforts, even in the face of declining nesting cover. Johann Walker, Ducks Unlimited's director of conservation planning for the Great Plains regional office, admits that predator control does work on a local scale, but it's not a viable long-term solution.
"The base duck population is widely distributed throughout the Prairie Pothole Region and there are millions of potholes, so it's difficult to see how predator management on a small scale will benefit ducks as a whole," says Walker. "Ducks Unlimited's approach is habitat-based. We are all about habitat, and that includes land outside of CRP."
Indeed, 175 units of 36-square miles translates to just 4 million acres, a fraction of the total nesting habitat in the PPR. Devney, however, isn't suggesting managers abandon conservation practices in favor of trapping skunks and other mammalian predators. Trapping efforts could help in pinpoint areas with poor nesting habitat, a looming issue as conservation programs face significant cuts.
"There's no question habitat is the key, but the hard truth is we will be dealing with a lot less habitat in the future," says Devney. "We know predator management works, so we think it's certainly another way to help ducks."