The population of large herbivores is declining, posing potential long-term threats to ecosystems worldwide, a new study found.
The report by an international team of wildlife ecologists, published Friday in Science Advances, analyzed data on 74 of the world’s largest herbivore species weighing over 100kg (220 pounds), their endangerment status, key threats and the ecological consequences of population decline.
Roughly 60 percent of the plant-eating animal populations–including camels, rhinos, zebras and elephants–are threatened with extinction in forest landscapes, savannahs, grasslands and deserts worldwide, places the researchers warned could ultimately become “empty landscapes.”
The study blamed the losses on several factors, including human poaching for meat and global trade of animal parts, habitat loss and competition for food and resources with livestock.
“Without radical intervention, large herbivores (and many smaller ones) will continue to disappear from numerous regions with enormous ecological, social, and economic costs,” the authors said. Some likely consequences are food reduction and habitat change for other animals, more frequent wildfires and a weaker nutrient cycle between plants and soil.
Large herbivores in developing countries, especially Southeast Asia, India and Africa face the greatest threats. Only one endangered species, the European bison, lives in Europe, and none are in North America, where prehistoric hunting and habitat loss have already diminished the population of most large mammals, according to the scientists.
“We hope this report increases appreciation for the importance of large herbivores in these ecosystems,” said William Ripple, professor in the College of Forestry at Oregon State University, who led the research. “And we hope that policymakers take action to conserve these species.”