The rapid rise in global extinctions is generally associated with habitat destruction, agricultural expansion, and human population growth, but a new study focuses on an underappreciated factor: bushmeat.
The researchers behind the report, the first-ever global assessment of the impact of human hunting, warn that if major changes aren’t made to limit human consumption and killing of these animals, many of them could reach the point of extinction.
Bushmeat, or wild meat, is a traditional food source for many rural communities in Asia, South America, and Africa. But as hunting practices become commercialized and inroads are made into even the most remote wild areas, the mammals relying on these ecosystems are no match for the hunting and trapping now taking place. This phenomenon basically guts habitats, leaving them devoid of the critical fauna that helps bring an ecosystem to life, and keeps it functioning smoothly.
"Extinction of species makes a hole in the trophic web — the linked food chains that all wild species are part of, from plankton to polar bears," said Katharine Abernethy, a researcher on the project and biologist at the University of Stirling in the UK. "If you remove a whole species, other must adapt. If adaptation is impossible, then more species will follow the hunted species to extinction."
Abernethy said the issue has been somewhat hidden because people suffer from "shifting baselines."
"If you have never seen a truly functional wild landscape, you do not realize how degraded most of the planet is," she said. "People growing up now in urban areas have no longer got realistic expectations for how much wildlife, how many lions, polar bears or bats they should have around them to keep the planet healthy."
The rate of vertebrate extinction is now around 1,000 times higher than it would be under normal conditions and flora and fauna are so stressed by human activities that many scientists believe the planet has already entered its sixth mass extinction. According to a report in Science, more than 75% of species of animals and plants could be gone within a few centuries. This is mainly due to the “twin threats of direct exploitation and habitat destruction” according to the report, which was published in the journal Royal Society Open Science, and relied on the International Union for Conservation of Nature’s (IUCN) red list to identify the endangered land mammals that are most at risk from hunting for food.
The researchers found 301 such species were at risk, including 168 primates. This represents about 7% of all the land mammals assessed by the ICUN and around a quarter of all endangered mammals. On top of the primates, there were high numbers of hoofed animals, bats, carnivores, marsupials and rodents. A few specific species include black rhinoceroses, tapirs, deer, tree kangaroos, armadillos, pangolin, black-bearded flying foxes, clouded leopards, and wilk yaks.
The animals are not only hunted or trapped for meat, but also medicine, trophies, and to be used as pets. According to the report, “the demand for wild meat is often exacerbated by simultaneous demand for the same species for medicinal, ornamental or trophy use, particularly in Asia, and so the same hunter or trader may be responding to multiple drivers.”
Overall, the international team that conducted the report views this dire analysis as erring on the side of caution.
"Our analysis is conservative," said William Ripple, distinguished professor of ecology at Oregon State University and leader of the team. "These 301 species are the worst cases of declining mammal populations for which hunting and trapping are clearly identified as a major threat. If data for a species were missing or inconclusive, we didn't include it.”
According to the study, in the Brazilian Amazon alone around 100,000 tons of meat worth $200 million is harvested annually.
Many people rely on these unsustainable wild meat sources for an important part of their diet. At the same time, not all wild meat is consumed for subsistence. In fact, a lot of it is sold in urban restaurants and markets as delicacies or exotic fares. The researchers note that in these urban areas, bushmeat consumption is positively correlated with wealth and is eaten mostly as a cultural legacy—meaning the behavior may be more subject to change, although it won’t be easy.
“Culture is a strong force in shaping human behaviors and preferences, but is slow to change and usually unreceptive to formal education programs unless there are financial incentives,” states the report. “Even in the face of the immediate danger of emerging diseases, hunters and wild meat consumers have been resistant to changing their cultural routines. However, cultural norms can change rapidly given strong pressure, as was the case for reducing the demand for shark fins.”
In 2010, a team of researchers determined that about five tons of bushmeat are smuggled weekly in tourist luggage through the Charles de Gaulle airport in Paris.
Professor David Macdonald, at the University of Oxford and part of the international team that produced the research, told The Guardian that it’s important “to distinguish between those people who have no choice but to eat bushmeat, and what is to be done for them, and people now living in towns who have a nostalgic memory for the time when they lived on bushmeat, but no longer need to, so it is a luxury.”
While this overhunting disproportionately harms larger animals, which are already more prone to extinction due to their resource demands and slow reproduction, protecting smaller mammals from going extinct is also extremely important. This is because they provide critical functions such as seed dispersal, consumption of vegetation and invertebrates, soil disturbance and prey items for other species, according to the study.
Abernethy said there are "stark consequences" for agriculture from the loss of things like pollination by bats; predation of pests like rats by smaller carnivores; or control of browsers like deer by larger carnivores.
"Many other, as yet unforseen changes are likely to occur in our ecosystems over the next 2 decades, and these will undoubtedly have economic consequences too," she said.
With all these factors in mind, the researchers came up with five broad tactics that could mitigate the threat of extinction facing these animals:
- Laws could be changed to increase penalties for poaching and illegal trafficking and to expand protected habitats for endangered mammals.
- Property rights could be provided to communities that benefit from the presence of wildlife.
- Food alternatives can help shift consumption to more sustainable species, especially protein-rich plant foods.
- Education could help consumers in all countries understand the threats to mammals that are hunted or trapped.
- Assistance in family planning could help relieve pressure on wildlife in regions where women want to delay or avoid pregnancy.
And of course, to accomplish any of this effectively, more support—both technical and financial—will be needed from developed countries with available funds and existing expertise. Unfortunately for now the researchers conclude that "there has been little conservation progress in reversing the fate of these threatened mammals despite several major summits convened on biodiversity conservation and protected areas."