Grey wolves, relentlessly targeted by human populations as a nuisance, are making a comeback in the western US and surprisingly are aiding bio-diversity.
The US National Park Service reintroduced 31 greys, listed on the endangered species list, to Yellowstone Park in 1995. They now number 120, flourishing on the ready supply of elk in the park.
Their arrival caused elk and coyote numbers to fall, but the numbers of eagles, pronghorn, foxes and wolverines increased, according to research presented late last month to the Society for Conservation Biology in the US. Neighbouring ranchers aren't too happy but they have been given permission to shoot wolves that attack livestock, and nine have been killed legally for this reason. The greys will be taken off the endangered list if numbers rise sufficiently at three habitats in Yellowstone, Idaho and Montana.