THE NORTH American duck population isn’t likely to achieve consistent, long term growth unless predators like the fox, raccoon and skunk are managed while hens are nesting.
That’s the conclusion of a comprehensive five-year study which shows that controlling predator numbers during the breeding season produces a stunning 300 percent increase in nest success. According to Delta Waterfowl, which conducted the study, it echoes what scientists have been saying about predators for years.
However, not everyone agrees. Ducks Unlimited has denounced the study, taking an official stand against predator management. Delta says that prior to the study, DU was uncommitted on the issue.
In an article in the November/December issue of DU magazine, executive vice president Matthew B. Connolly, Jr., said, “There are proponents of plans to alleviate the predator problem that, in theory, may sound wonderful. Basically, these plans are based on eradicating predators from the prime duck breeding areas. Get rid of the predators, they say, and duck populations will increase exponentially. Not so.”
Connolly said DU “takes a holistic approach” to providing “sustainable ecosystems that support the birds’ life cycle requirement” and added that recent increases in duck numbers prove DU’s “blueprint is working.”
Lloyd Jones, a regional vice president at Delta waterfowl was disappointed by what he sees as an attempt to discredit Delta’s research.
“I thought we were all in this together,” Jones said. “It was our hope that DU and other state, federal and private conservation organizations would use what we’ve learned to help duck populations expand.”
What Delta says they’ve learned is that predators are a major reason the Fall Flight Index of ducks slipped from over 90 million birds in 1970 to just 59 million in 1993. Delta adds that when the billions of dollars invested in habitat projects didn’t slow the free fall, they decided to examine other factors, launching the study on the impact of predators.
Since 1994, Delta says they’ve monitored 320,000 acres of upland cover.
“We hired a professional to trap predators on half those acres, then compared the nest success with similar tracts of land that were not trapped,” Jones said. “The five-year average for ‘treated’ areas was 43 percent nest success while in the untreated areas, only 14 percent of the nests were successful.”
Scientists know a 15-20 percent nest success is necessary just to maintain the duck population at existing levels.
“What’s really frightening about those numbers is that we’ve been in a wet cycle since we launched our study,” Jones added. “Not only have we had ideal water conditions, but in many areas we have exceptional nesting cover thanks to the Conservation Reserve Program. Still, the untreated areas haven’t even produced ducks up to the bare maintenance level. Predators are still destroying 86 percent of the nests.
“If we’re barely staying ahead of the game under ideal conditions, what’s going to happen when the Prairie Pothole Region goes dry or when we lose CRP?” Jones asks.
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New York’s Dept. of Environmental Conservation Commissioner John P. Cahill today announced the introduction of the 1999 New York State Migratory Bird Program image. This year’s artwork features a pair of bufflehead ducks flying over New York’s Hudson River with the historic Rondout II lighthouse in the background.
“The restoration of the Hudson has become a priority of New York’s government and its citizens,” Cahill said. “These efforts are now paying off. The Hudson has regained much of its historical beauty and grandeur, which are captured in this wonderful painting by Richard Clifton.”
