A lost century for forest elephants

Date: August 30, 2016

Source: Wildlife Conservation Society

Because forest elephants are one the slowest reproducing mammals in the world, it will take almost a century for them to recover from the intense poaching they have suffered since 2002. Not only does it take more than two decades for female forest elephants to begin reproducing, but they also give birth only once every five to six years.

The findings are from a first-ever study of forest elephant demography published Aug. 31 in the Journal of Applied Ecology.

There are two species of elephants in Africa. Savannah elephants make up the majority across the continent, with smaller numbers of the more diminutive forest elephants restricted to tropical forests. Forest elephants have experienced serious poaching, driving an estimated population decline of 65 percent between 2002 and 2013 according to a study led by the Wildlife Conservation Society (WCS).

Their reported low birth rates mean that it will take forest elephants at least 90 years to recover from these losses, according to researchers from the WCS, the Cornell Lab of Ornithology's Elephant Listening Project, Colorado State University, and Save the Elephants. The team used decades of intensive monitoring data that recorded births and deaths of the elephants using the Dzanga Bai in Central African Republic, part of the UNESCO World Heritage Sangha Trinational area. (Dzanga Bai translates roughly as "village of elephants.")

"This work provides another critical piece of understanding regarding the dire conservation status of forest elephants," said the study's lead author Andrea Turkalo, WCS Associate Conservation Scientist, who over several decades collected the detailed data on the Dzanga elephants despite tough logistical challenges and political instability.

Using data Turkalo collected from 1990 to 2013 during nearly daily visits to a mineral rich forest clearing, or bai, that attracts elephants and other wildlife, the authors were able to uncover the age at which the forest elephants had their first calves, the length of time between calves, and other behaviors.

The team found that forest elephants begin breeding later and have much longer calving intervals than other elephants, which means the population takes much longer to increase.

Continued