Wildlife Numbers Sink 58% Worldwide in Just Four Decades

Giraffes fighting in South Africa

WWF found the planet’s wildlife populations have plunged nearly 60 percent since 1970. Researchers believe the number could drop to two-thirds by the end of the decade. The report also revealed that vertebrates in streams, lakes, wetlands experienced the biggest losses. WWF experts think the big culprits are global warming, habitat loss, poaching, and pollution.

Study investigators estimate that ‘business as usual’ could further fuel declines in wildlife numbers. But authors pointed out that humanity has reached a point that leaves no room for excuses to continue. So, they urged everyone to act.

WWF publishes the Living Planet Report every other year. But some experts criticized this year’s findings.

The Study

The latest research included 3,700 species of vertebrates including mammals, birds, fish, and reptiles. The number accounts for just six percent of the total number of vertebrates around the planet. Researchers based their analysis on studies, official reports, and surveys conducted by nonprofits and conservationists.

The team included only data on species that have been documented since 1970. Additionally, each species had to appear in the documentation at least twice to make it in the study. Next, researchers analyzed how the numbers of each species changed over time.

The findings were adjusted in cases where there was little data such as amphibians in the tropics. In other cases, such as the Arctic birds, data was abundant. So, the team ensured that the extra information on the declines did not alter the overall picture.

In 2014, the group found wildlife numbers have sunk by a half since 1970. So, the new findings suggest that the situation is getting worse. But some animals saw greater losses than others. Researchers noted freshwater species dwindled at a faster pace. These species saw an 81 percent decline over the same period. Pollution and dam building destroyed most of these species’ ecosystems. Other species saw major losses too such as African elephants or sharks. In those two cases, poaching and overfishing played a huge part.

WWF investigators now estimate vertebrate numbers are declining by 2 percent every year. At this rate, the populations could see a 67 percent loss by 2020. Co-author of the study Dr. Robin Freeman is concerned that poaching and overexploitation may make things even worse. Fortunately, the data refers to species that are not yet extinct. And as long as they are not vanishing, there is still something we can do about it to stop it, Freeman said.

Report Met with Criticism

Nevertheless, the report drew some criticism. Duke University researchers said the study has too many gaps to be reliable. So, it is premature to put a single figure beside a global wildlife decline. Duke scientists said while some numbers are “sensitive” others may be misleading. For instance, many of the reliable data refers to species in the Western Europe. For other parts of the world, the data is “sketchy.”

“They’re trying to pull this stuff in a blender and spew out a single number,”

Prof Stuart Pimm from Duke University said.

In response, Dr. Freeman acknowledged that his team lacked data on some species such as tropical amphibians. But that happened because data was not available. However, the method researchers used is designed to prevent sketchy results. Freeman believes that even in the species on which researchers lack any data some animals may be faring a lot worse, not better.

For the full report click here.