Monday, November 26, 2007

Predators and Duck Demographics



The October-November issue of National Wildlife magazine, the house organ of the National Wildlife Federation, has a piece on it about skunks which notes that a research project on Mephistus mephistus being conducted by Travis Quirk, and funded by Delta Waterfowl, is being done in a 30-square mile area of Manitoba "that once was one of the most productive duck-breeding regions in the province. '

However, as the article notes,

"Nest success has fallen well below the population maintenance levels in recent decades and the main culprits are the growing numbers of nest-raiding skunks, raccoons, foxes and mink. 'There are a lot of animals out there that eat duck eggs,' Quirk says, 'even white-tailed deer and ground squirrels.'


"Waterfowl managers estimate that predators typically destroy 90 percent of upland duck nests across the northern prairie breeding grounds, along with countless songbird nests. When predator numbers climb, nest success declines in lockstep. On a smaller research plot within Quirk's study area, only 1 percent of the mallard nests produced ducklings when his skunk population peaked at four per square mile, more than double the number when he began the study.'

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