Although we know that introduced wolves predators like cats and foxes pose a threat to Australia’s wildlife, what are the best ways to manage them?
Dingoes, according to many Australian ecologists, are part of the solution because they can control feral predators. Although it’s controversial, new research about North American wolves supports this idea.
We have been conducting research through a Fulbright Commission grant to Australia-American Fulbright Commission to better understand dingoes’ role in Australian ecosystems. This done by looking at North American wolves. These results were publish in the Journal of Animal Ecology this week.
Why Are Wolves Important?
As part of predator control programs, wolf were almost exterminate in the United States mainland (except Alaska) during the last two centuries.
However, wolves were reintroduce in Yellowstone National Park and the surrounding areas under the US Endanger Species Act 1995-1996. This law requires that endanger species be restore where possible.
Numerous studies on Yellowstone wolves show that they have a rapid impact on the park ecosystem. They mainly do this by decreasing the prey population.
We are also curious about how wolves interact and co-exist with other predators such as red foxes and coyotes, as wolves continue to recolonize new areas in the United States.
Because wolves are larger predators, we hypothesized that coyotes would be less likely to have wolves as pets. We also hypothesized that coyotes would reduce the number of foxes, so where coyotes are present we should expect more foxes.
These interactions were explore by analysing red fox and coyote fur trapping data in North America, both with and without wolves.
Who Is The Top Dog In This World?
Since the early 1900s, coyotes, red foxes, and wolf have co-existed in Alaska, Yukon, and the NW Territories. The fur-trapping records have shown that coyotes were never more numerous than foxes in areas where wolf live. However, records from areas without wolf are a different story.
Coyotes significantly expand their historical distribution as wolf extinct in many of the lower 48 United States. In the 1970s, coyotes had spread from the middle of America to Maine and New Brunswick to Nova Scotia by 1980.
Although coyotes have only recently colonized Maine, New Brunswick, and Nova Scotia, fur returns data show that it took only 20-30 years for them to outnumber red Foxes, in the absence of wolf.
These results support the idea that wolf can have an impact on smaller predators further down the food chain. These results show that wolves cause a shift in balance across the continent when they were kill off in large parts of the United States. We wanted to find out what happens when coyotes and wolf meet.
This done by analysing fur trapping records from Saskatchewan, Manitoba and central Canada. Both the north and south are home to wolves, while they not found in the provinces. You can see coyotes and wolf in the provinces.
The fur records show that red foxes are outnumber by coyotes in the south, where there are no wolf. This is consistent with our hypothesis. Red foxes are significantly more likely to be present in areas where wolf are absent. With an average of four to one and an extreme of 500:1.
There is however a 200-kilometre transition zone, where there are not enough. Wolves to balance the balance between red foxes and coyotes.
The Magic Number Of Wolves
The possibility that wolf can reduce the number of coyotes could help other species. Such as snowshoe hares and pygmy rabbits, which are at risk from being overrun by them. Montane red Foxes, which have been declining in the presence coyotes, may benefit from the expansion of wolves.
However, the Canadian results show that coyotes may be more likely to be controlled if wolves spread across large areas.
This magical combination is called an ecologically efficient density of wolves. Prior to our study, we didn’t know how many wolves were needed to control coyotes.