Colorado elk grew fearless with predator absence
By RICK WEISS
Washington Post
Elk in Siberia that hear recorded calls of bears, tigers or wolves tend to cluster together, become vigilant and in many cases bolt in a near panic. Yet elk in Colorado’s Rocky Mountain National Park that hear the recordings continue to graze with nonchalance.
A sign of American toughness?
Hardly. Rather, it is good scientific evidence that fear of predators is not hardwired into animals’ brains but is maintained by ongoing exposure to the risk posed by those predators.
The large carnivores that once attacked elk in Colorado have been gone for decades, and with those predators went the fear that once sent the elk fleeing.
Those findings, from research led by Joel Berger of the Wildlife Conservation Society in Teton Valley, Idaho, stand to help conservation biologists as they reintroduce predators such as wolves into areas where those animals have disappeared.
Berger conducted experiments in 19 areas around the world, including some where native predators of caribou, moose and elk such as wolves, grizzly bears and Siberian tigers remain in place, and others where those predators had been chased away or killed off years ago.
The results, published in an online issue of Conservation Biology, show not only that fear dissipates in the absence of predators but also that it returns in areas where the predators have been reintroduced including Grand Teton and Yellowstone national parks, where wolf populations have been replenished at a cost of tens of millions of dollars.
The data is timely, scientists say, because plans are in the works to allow large numbers of wolves to be hunted in some U.S. areas where they were reintroduced.
The results suggest it may be important to keep those populations high enough so that prey species maintain proper vigilance levels.