“Notably,” said the study, “all of the threatened species are found in developing countries, with the exception of the European bison, with developed countries having already lost most of their large mammals in the ongoing megafauna extinction.” 
 
 The animals are suffering from range collapse, a contraction of the land available for them to survive. “The main threats … are hunting, competition with livestock and land-use change such as habitat loss, human encroachment, cultivation and deforestation,” the researchers found, noting that “extensive overhunting for meat across much of the developing world is likely the most important factor.” 
 
 
 
 The main herd of elephants at Zakouma National Park in Chad in 2013. Furthermore, at least in part due to poaching, Africa’s western black rhinoceros (D. bicornis longipes) was declared extinct in 2011 (1). With rhinoceros horn worth more than gold, diamonds or cocaine on illegal markets, rhinos could be extinct in the wild within 20 years in Africa, said the researchers. The highest numbers of threatened large herbivores live in developing countries, especially Southeast Asia, India and Africa, the scientists report. The consequences of large wild herbivore decline include: 
 
 Loss of habitat: for example, elephants maintain forest clearings by trampling vegetation 
 
 Effects on the food chain: large predators such as lions, leopards, and hyena rely on large herbivores for food 
 
 Seed dispersal: large herbivores eat seeds which are carried over long distances 
 
 Impact on humans: an estimated one billion people rely on wild meat for subsistence while the loss of iconic herbivores will have a negative impact on tourism 
 
 The biggest losses are in South East Asia, India and Africa. The author, Kent H. Redford, then a post-doctoral researcher at the University of Florida, first used the term “empty forest.” While soaring trees and other vegetation may exist, he wrote, the loss of forest fauna posed a long-term threat to those ecosystems.
– A new study published in Science Advances is being described as "horribly bleak," at least as far as rhinos, camels, and elephants are concerned: It finds that the majority of the planet's giant herbivores face the risk of extinction. The wildlife ecologists write that while about 4,000 species qualify as a "terrestrial mammalian herbivore," they zeroed in on just 74 such species whose mean adult body mass is 220 pounds. It's the "first time" just those large species have been viewed collectively, says study leader William Ripple of Oregon State University; per the International Union for the Conservation of Nature, 44 of them, or about 60%, are threatened with extinction. The researchers identified "twin threats": habitat change—25 of the 74 have lost 81% of their historical range—and hunting, with an estimated 1 billion people consuming wild meat. Their loss could have a dire ripple effect, the scientists explain: "Large herbivores are irreplaceable as seed dispersers," they write, "able to ... deliver many more seeds per defecation event over longer distances" as compared to other animals. It's one of many things they impact, from the frequency of wildfires to the creation of new channel systems in swamps. Ripple previously looked at large carnivores through the same lens and found similar issues, and he tells the BBC his latest study "adds another nail to [the carnivores'] coffin. It's no use having habitat if there's nothing left to eat in it." A press release notes that of the species reviewed, just one—the European bison—is found on the continent of the same name, and none in North America, thanks in part to "prehistoric hunting." Southeast Asia, India, and Africa are home to the bulk of the threatened giant herbivores. (Meanwhile, US zoos are letting their elephants die out.)