CORVALLIS, Ore. – Imagine a world without carnivores – animals such as bears, lions, and wolves. Researchers at Oregon State University say if changes are not made now, the decline of predators will continue, and it is taking a toll on eco-systems around the world.
OSU Professor Bill Ripple teamed up with researchers from around the world to study large carnivores. The team called for an international initiative to conserve the carnivores in co-existence with people. Ripple and his co-author at OSU, Robert Beschta, researched the existence of wolves and cougars in North America.
“The word carnivore can be interchanged with predator,” Ripple said. “These are any animals that their diet is meat.”
Ripple says around the world, there has been an overwhelming decline in large carnivores.
“Seventy-seven percent of the large carnivores in the world are declining and 61 percent are considered threatened.”
Ripple says the main cause for the carnivores’ disappearance is human action, through persecution or through development on forested lands. He says carnivores need a lot of space, and when their habitats are invaded, their populations decline.
“These animals sit on top of the food web and they influence everything below them,” Ripple said.
Large carnivores such as wolves usually prey on animals such as elk, deer, or moose.
“Animals like deer or moose are what we call herbivorous animals,” he said. “So they eat just plants. So their whole diet is vegetation.”
With less carnivores, less of their prey is killed.
To show the importance of carnivores, OSU researchers are also studying Yellowstone National Park, where they are seeing the opposite trend: wolves are actually coming back to the area. They are scaring off the elk, which means more of the vegetation along the river banks is growing back. Ripple says this has brought back beavers, birds, and fish to the area.
In comparison, in Olympic National Park for example, Ripple says wolves were persecuted in the 1900s. More elk now inhabit the area, which means less riverside shrubs and less of a diverse eco-system.
“For example, the cottonwood trees have declined there, and we think erosion of the rivers has increased,” Ripple said.
Ripple says the decline in carnivores is not just affecting biodiversity. It is also providing negative economic consequences. In parts of Africa, researchers say there are fewer lions, which means the population of its prey is increasing, such as baboons.
“They raid the farmers’ crops,” Ripple said. “So now, in extreme cases, the farmers need to keep their children home from school to guard these fields from these raiding baboons.”
Ripple says he hopes the research will promote more conversations about co-existence.
“One thing that’s important if we want to conserve the large carnivores is to promote tolerance by humans,” he said. “These animals can be hard to live with, and they can be dangerous to humans or their livestock. But I think if we have human tolerance as an item to consider, then the conservation of these animals might be more promising.
“The scientists are generally concerned about these large creatures going extinct,” he said. “And some of them are already close to extinction. So I think human tolerance is an important topic for discussion.”