Elephants, rhinos, hippopotamuses, gorillas and several other of the world’s largest herbivores are in danger of becoming extinct. According to a study by an international team of scientists, not only will the current trends be devastating to these animals but they will also have serious consequences for the ecosystems in which they live and other species as well.
The study, called “Collapse of the world’s largest herbivores,” was published in the open-access online journal Science Advances in May. In their research, scientists studied 74 different species of herbivores that weigh an average of 220 pounds at adulthood – essentially the size of reindeer or larger. They found that 60% of species in the study are now considered threatened. UCLA professor of ecology and evolutionary biology and study co-author Blaire Van Valkenburgh says:
“For some of the largest animals, such as elephants and rhinos, it is likely a matter of a few decades before they are extinct — and no more than 80 to 100 years for the rest of the large herbivores. Even though an individual elephant or rhino might persist in the wild somewhere in Africa, they will be functionally extinct in terms of their impact on the ecosystem.”
The study explains that the two largest threats to these animals are hunting and habitat loss. Other factors include increasing human populations and competition with livestock, particularly in developing nations where livestock production tripled from 1980 to 2002.
Research showed that:
- From 2002 and 2011, the number of forest elephants decreased by 62%.
- From 2007 to 2013, the number of poached rhinos jumped from 13 to 1,004 per year.
- From 2010 to 2012, more than 100,000 elephants or one-fifth of the world’s wild savannah elephant population were poached.
Van Valkenburgh says:
“Decades of conservation efforts are being reversed by the entrance of organized crime into the ivory and rhino horn markets. If this were to keep up, there would be very few or no savannah elephants in 10 years, and no African rhinos in 20 years.”
One major problem is that the financial incentive for hunting these animals is huge. For instance, rhino horns are more valuable by weight than gold, diamonds or cocaine, reaching as high as $60,000 per pound in Asia. Because of this, the study proposes creating counter financial incentives for people living near the animals to safeguard them, so it would become more profitable to protect the animals than to poach them. The study also stresses the need for social marketing and education campaigns to drive down demand for animal products as food and consumer goods.
The scientists say:
“Large herbivores, and their associated ecological functions and services, have already largely been lost from much of the developed world. Now is the time to act boldly, because without radical changes in these trends, the extinctions that eliminated most of the world’s largest herbivores 10,000 to 50,000 years ago will only have been postponed for these last few remaining giants.”
The study also notes that the Pleistocene Epoch, which ended around 11,700 years ago, saw more than 40 species of herbivores in which adults weighed 2,200 pounds or more, but today there are only eight. The extinction of these “mega-herbivores” has drastically influenced our planet’s ecosystems. For example, large herbivores are the primary food source for predators and scavengers and the way they walk over and consume plants affects how vegetation grows. In addition, they are relied on for food on by humans, especially in developing nations, with an estimated 1 billion people depending on wild meat to survive.
The conclusion to the study states:
“Without radical intervention, large herbivores (and many smaller ones) will continue to disappear from numerous regions with enormous ecological, social, and economic costs.”