January 2014: Large carnivores, those at the top of their respective ecosystems, face serious threats and are experiencing massive declines in their populations and geographic ranges around the world.
Further drops in leopard populations will have an impact on the entire ecosystem of their range
A new study published in Science magazine highlights how these threats have affected the conservation status of the 31 largest carnivores on earth, particularly in south and east Africa, southeast Asia and the Amazon region of South America. Three-quarters of these top predators, including big cats, bears and wolves, are in decline across the world, and most inhabit only half their ancestral areas.
In recent times, it has been humans who have disrupted the ecological structure through habitat destruction, which affects not only the carnivores’ living area but also the availability of their prey. There has also been a continuing opinion that large predators pose an unacceptable threat to people and other animal life, resulting in their active removal.
"Human tolerance of these species is a major issue for conservation," said lead author of the paper, Professor William Ripple of Oregon State University. "We say these animals have an intrinsic right to exist, but they are also providing economic and ecological services that people value."
Concern about these massive declines centres on the fact that large carnivores have substantial effects on the structure and function of diverse ecosystems. They are necessary for the maintenance of biodiversity and the function of the ecosystem. Human actions cannot fully replace the role of large carnivores in maintaining nature’s delicate balance.
The unexpected effects of removing large predators include changes to the abundance and richness of bird, smaller mammal and invertebrate life. In Yellowstone Park in the US, the near extinction of wolves saw a rise in deer and elk, which in turn led to vegetation being over-grazed, which removed habitat for birds, small mammals, insects and invertebrates. The writers of the paper advocate tolerance and coexistence with large carnivores as being crucial to determining the fate of all that depends upon them, including humans.
The study proposes a Global Large Carnivore Initiative to coordinate local, national, and international research, conservation, and policy to maintain large carnivores and their habitat wherever possible. The writers of the paper believe that preventing the extinction of these species and therefore the loss of their irreplaceable ecological function and importance, will require novel, bold, deliberate and immediate actions, given the severity of the threats they face.