The population of African forest elephants plummeted 62% in the past decade, according to a new study. The figure, which the authors blame on ivory poachers, comes as policymakers discuss ways to curb the ivory market at the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) meeting in Thailand.
"Hopefully these numbers will help convince decision-makers that there is a problem," says wildlife biologist Fiona Maisels of the Wildlife Conservation Society and the University of Stirling in the United Kingdom, first author of the new paper.
Forest elephants, which often live closer to human populations than the larger savanna elephants, have been particularly hard-hit by ivory poachers. After declines in the elephant population last century, a 1989 international ban on ivory initially led to signs of a resurgence in the animals. Since then, anecdotal evidence and surveys taken in individual parks suggested that heightened demand for ivory in China has once again led an uptick in elephant slaughters. "We knew it was bad, but their habitat is all under forest coverage, so you can't just go out and do aerial surveys like you can for savanna elephants," Maisels says.
To get a more complete picture, Maisels and a team of more than 60 researchers from around the world helped coordinate and assemble data from 80 individual surveys taken from 2002 through 2011 in central African locales that are known to be the primary habitats for forest elephants. Some sites were in formally protected areas; others were in spots that conservationists would like to see protected in the future. In each of the locations, which spanned Cameroon, Gabon, the Central African Republic, the Democratic Republic of the Congo, and the Republic of the Congo, trained biologists surveyed land for elephant dung, an indicator of the elephant population in the area. "This is the first time we've managed to do a comparison of all these sites in a very coordinated way," Maisels says.
When the team crunched the numbers, it found that just during the 10-year span covered in the new surveys, the elephant population declined by 62% and the land area inhabited by elephants dropped by 30%. Areas lacking guards, closest to roads, and in countries with high levels of corruption had the most elephant population decline, the researchers reported today in PLOS ONE.
"I think these numbers are either very accurate or even a bit conservative," says biologist Richard Ruggiero, the chief of the Near East, South Asia, and Africa Branch in the U.S. Fish and Wildlife Service's Division of International Conservation in Arlington, Virginia, who was not involved in the new work. Because many of the surveys took place in protected areas, he says, they could overestimate elephant populations—elephants often flee into the protected zones to escape nearby poaching.
"These surveys are as good as they can be," Ruggiero adds. "They are certainly very objective and very rigorous." Estimates on the absolute population of elephants at any given time must be taken with a grain of salt, he says, but overall trends seen over years of sampling the same areas in a standardized way are generally more accurate.
The new numbers are not surprising to conservationists who work in the area, both Ruggiero and Maisels say, but are needed to convince others of the problems and provide a starting point to see the effect of future conservation efforts. "When you're on the ground and you know what to look for, you don't need a survey to see what's happening," Ruggiero says. "But unless you can put a more or less objective metric on it, you're not going to get this in front of the people who need to see it."
The challenge now, Maisels says, is for those countries represented at the CITES meeting, which lasts until 14 March, to put together new policies to curb the ivory trade. The key, she thinks, will be to stop the trade within China, lowering the demand for ivory and the price. Previous programs aimed at this aspect of the market have been more successful than those specifically aiming to stop the poaching, she says.