For the African forest elephant, a road is a highway to death, says a team of researchers, who trekked more than 8000 kilometers in five African countries to assess the animals' populations. Logging roads have given poachers increased access to the elephants' dwindling sanctuaries in the Congo Basin, and the reclusive animals' numbers are plunging as they are slaughtered for their ivory, the team's 2-year survey shows. "Forests that were formerly safe havens for elephants, such as those in the Democratic Republic of the Congo, are now virtually empty," says Mike Fay, a biologist with the Wildlife Conservation Society (WCS) in New York.
Forest elephants (Loxodonta africana cyclotis) live only in the woodlands of West and Central Africa. In 1989, the last time a survey was made, scientists estimated the overall population at 172,400. That count was based on a foot survey, because the forest is too dense to tally the elephants from the air, as is done for their cousin, the savannah elephant (L. africana Africana). The new study, published in the current PloS Biology and headed by Stephen Blake, a biologist with WCS, was based on indirect measures, such as counting dung piles along transect lines and tallying carcasses left by poachers. The dung density was then converted to elephant density, with many areas--even some national parks--estimated to have fewer than 0.6 or less individual elephants per square kilometer. "It's a bleak picture," says James Deutsch, a conservation biologist at WCS.
Most revealing: The number of elephant dung piles increased significantly away from roads built to give loggers access to African hardwoods. In telling contrast, the signs of poachers, such as elephant carcasses without tusks, were most concentrated close to these roads. "It shows without question that poachers are also using the logging roads," to hunt the elephants for their ivory and meat, says Fay. Moreover, to escape their killers, the forest elephants, which were once widely distributed, have sought safety deep inside national parks and reserves, the researchers report. For instance, the largest remaining wilderness in the Congo basin, Gabon's Minkebe National Park, is home to some 22,000 elephants, they estimate.
"They've shown that the closer elephants are to roads, the more mortality they will suffer," says Sam Wasser, a conservation biologist at the University of Washington, Seattle. "An entire species of elephant is being wiped out. It's all being fueled by the demand for ivory in China and Japan, and the soaring price of high-quality ivory," which has quadrupled in price since 2004 to $850 per kilo. Unfortunately for the forest elephant, even the safe zones it now relies on may turn into killing zones: The authors of the study note that logging roads are being built close to Minkebe National Park.