"Over the last 200 years, Australia has had the highest extinction rate in the world," Newsome said. "The debate is about whether the dingo can provide positive ecological benefits. Where dingoes have been removed, the impacts of introduced red foxes and feral cats have been quite severe on native fauna."
Dingoes are managed as a pest in New South Wales, the country's most populous state. To reduce dingo predation in the livestock industry, Australia also maintains the world's longest fence, which runs for 5,500 kilometers (3,400 miles) in an attempt to exclude dingoes from almost a quarter of the continent.
In North America, the effect of wolves on coyotes and red foxes provides a natural case study that can be instructive for Australians. "Australians can learn a lot from how wolves are managed in North America, and Americans can learn from the ecological role of the dingo," Newsome said.
As coyotes have expanded in North America, they have become a major cause of concern for the livestock industry. In the United States in 2004, researchers estimated annual losses due to coyote predation on sheep and cattle at $40 million. To reduce those damages, the Wildlife Service of the U.S. Department of Agriculture has a program to reduce coyote numbers, an effort that has drawn criticism from conservation groups.
In reviewing the fur trapping data from two U.S. and six Canadian jurisdictions, Newsome and Ripple eliminated potential sources of bias such as records from fur farms that raise foxes. The fur prices of coyotes and red foxes are also strongly correlated, and the two species occupy much of the same types of habitat, so they are equally likely to be targeted and caught in hunters' traps.
"This study gives us a whole other avenue to understan
|Contact: William Ripple|
Oregon State University