Humans are currently eating some of the world’s biggest animals into extinction, from salamanders to ostriches, scientists have warned. A study into the world’s megafauna—or large animals—showed 59 percent are threatened with extinction, and a further 70 percent are declining in number.
Researchers set out to understand the part humans play in this. At 98 percent, almost all animals of the 162 classified as threatened were in danger because of humans hunting the creatures for food or body parts. Animals such as whales, sharks, sea turtles, alligators, giant salamanders, flightless birds, lions, tigers, bears, elephants, giraffes, and rhinos were included in the work.
“Surprisingly, direct harvesting of megafauna for human consumption of meat or body parts is the largest individual threat to each of the classes examined,” the authors wrote in their study.
Our species has emerged as a “super predator” since the Pleistocene period which lasted from around 2.5 million to 11,700 years ago, wrote the international team of researchers in their study published in the journal Conservation Letters.
The problem partly stems from the fact humans have spent the past five centuries perfecting technologies and methods that have enabled us to kill wild animals at closer proximity. In this time, 2 percent of megafauna have gone extinct, compared with 0.8 percent of all animals.
More populations of megafauna are threatened and have higher rates of decreasing populations than all other vertebrates put together, Dr. William Ripple, study co-author and distinguished professor of ecology at Oregon State University College of Forestry said in a statement.
In their study, the team grouped the 362 existing species of megafauna into six categories: mammals; ray-finned fish (such as salmon and sea horses); cartilaginous fish (like sharks, skates, and rays); amphibians; birds; and reptiles.
They studied existing data on their numbers and threats of danger in the wild. To be included, the animals had to be bigger in size than the rest in their class. The mammals and fish weighed at least 100 kilograms (220 pounds), while the lower limit was 40 kilograms (88 pounds) for the other animals.
The Chinese giant salamander was identified as among the animals under threat. Considered a delicacy in some parts of Asia, scientists regard the animal a living fossil as it dates back 170 million years. It is endangered not only by hunting but pollution and development, the authors warned. The Somali ostrich, meanwhile, is hunted for meat, feathers, leather, and their eggs collected.
Pointing to another example, Ripple said: "Through the consumption of various body parts, users of Asian traditional medicine also exert heavy tolls on the largest species.
"In addition to intentional harvesting, a lot of land animals get accidentally caught in snares and traps, and the same is true of gillnets, trawls and longlines in aquatic systems," Ripple said. "And there's also habitat degradation to contend with. When taken together, these threats can have major negative cumulative effects on vertebrate species."
Ripple told Newsweek: “It is ironic that these largest species are some of the most loved animals on Earth and at the same time, we are in the process of directly killing them off.”
However, the authors acknowledged that megafauna can be a vital source of food to people in some developing nations.
At the launch of the study, the researchers expected the degradation or loss of habitats to be the biggest threat to these species. “I was surprised to see that harvesting by humans is the biggest threat to many of these animals,” Ripple told Newsweek.
He said he hopes governments and policymakers will take notice of the results, and use them to create educational programs, laws, and regulations to protect the world’s largest animals.
Last year, a separate study published in the journal BioScience similarly warned of the decline of a type of megafauna: specifically turtles. The authors said most turtles are threatened or extinct due to dangers including climate change, the pet industry, and the destruction of their habitats.