Wednesday, June 18, 2014

Wolves Have An Effect On Coyotes, Foxes Across North America 

Fur trapping records across North America have shown that the population of wolves in a given area has a dramatic effect on smaller animals, according to scientists. The study included areas from Alaska and Yukon to Nova Scotia and Maine. 

In areas where wolves are present, red foxes are favored. In areas where wolves are absent, coyotes are favored.

Coyotes outnumber foxes an average of 3-to-1 where wolves are present. However, in the areas where wolves are absent, foxes outnumber coyotes an average of 4-to-1, 500-to-1 in one area. In one 124 mile transition area where wolves are present, there are too few of them to alter the balance between the coyotes and foxes.

Thomas Newsome and William Ripple   
from the Oregon State University Department of Forest Ecosystems and Society conducted the study and published the findings in the Journal of Animal Ecology by the British Ecological Society.

“As wolves were extirpated across the southern half of North America, coyotes dramatically expanded their range. They were historically located in the middle and western United States, but they dispersed all the way to Alaska in the early 1900s and to New Brunswick and Maine by the 1970s. said Newsome in a recent statement. 
So essentially coyotes have been dispersing into wolf and red-fox range in the north but also into areas where wolves are absent but red fox are present in the East,” said Newsome.

Newsome earned a Ph.D. from the University of Sydney, Australia, where he specialized in the study of dingoes. There is controversy in Australia about the dingoes and their role in decimating wildlife. “Over the last 200 years, Australia has had the highest extinction rate in the world. 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,” Newsome explained.

Dingoes are considered to be a pest and to reduce the destruction of livestock, Australia has built the world’s longest fence – 3,400 miles – to prevent the animals access to a quarter of the continent.

Newsome believes that the study on wolves and the affect they have on coyotes and foxes could be helpful to Australia. “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.

The range of coyotes has expanded greatly across North America and has become a major concern in the livestock industry. In 2004, there was an estimated $40 million loss in cattle and sheep. The Wildlife Services of the US Department of Agriculture have implemented a program to reduce the number of coyotes to help cut losses caused by the predator. However, it has gathered criticism from conservation groups.

“This study gives us a whole other avenue to understand the ecological effects of wolves on landscapes and animal communities,” said Ripple. It has shown the huge effect that the removal of top predators has on the ecosystem.
Wolves are also expanding to many areas of the US since their reintroduction into Yellowstone National Park and surrounding areas in 1995. Scientists are studying the wolves’ interaction with other species, especially coyotes and red foxes, to see the impact they have on the populations.

Reposted from Before Its News 

Photo credits:

Wolf Identification - Western Wildlife Outreach

Red fox 
Found on


Dingo - Wikipedia, the free encyclopedia

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