Researchers determined how factors such as habitat loss and human persecution create "hot spots" of carnivore decline.
Populations of large meat-eaters such as "lions, dingoes, wolves, otters, and bears" have been declining causing changes in local ecosystems, an Oregon State University news release reported.
Over 75 percent of the 31 large carnivore species have seen a significant population decline; 17 percent of these species now reign over less than half of their original habitats.
"Globally, we are losing our large carnivores," William Ripple, lead author of the paper and a professor in the Department of Forest Ecosystems and Society at Oregon State University, said in the news release.
Large carnivore populations have been all but exterminated in Western Europe and the eastern United States and are declining in regions such as "Southeast Asia, southern and East Africa and the Amazon," the news release reported.
"Many of [the species] are endangered," Ripple said. "Their ranges are collapsing. Many of these animals are at risk of extinction, either locally or globally. And, ironically, they are vanishing just as we are learning about their important ecological effects."
The researchers called for an "international initiative" to help humans better-coexist with these predators. The team pinpointed a number of species that have a prominent effect their ecosystem (trophic cascades). These choice species included "African lions, leopards, Eurasian lynx, cougars, gray wolves, sea otters and dingoes."
In a study on cougar and wolf populations in Yellowstone park, the researchers found a decline in these species led to an increase in "browsing animals" like deer and elk.
An increase in these grazing animals impacts" vegetation, shifts birds and small mammals and changes other parts of the ecosystem in a widespread cascade of impacts," the news release reported.
Lynx have also been found to lead to a booming roe deer, hare, and fox population if their species declines, leaving less predators around to hunt the grazers.
The researchers hope to call attention to the fact that predator-discrimination (such as the idea that they deplete local wildlife populations) is "outdated."
"Human tolerance of these species is a major issue for conservation," Ripple said. "We say these animals have an intrinsic right to exist, but they are also providing economic and ecological services that people value."
Some of these services include "carbon sequestration, riparian restoration, biodiversity and disease control," the news release reported.
"Nature is highly interconnected," Ripple said. "The work at Yellowstone and other places shows how one species affects another and another through different pathways. It's humbling as a scientist to see the interconnectedness of nature."
