Study uncovers a heightened threat to African forest elephants

Forest elephants

Conservation efforts for the African forest elephant have languished by how little is known about the very large animal, but a recent study from a research team involving a UO biological anthropologist could help address that.

Associate professor Nelson Ting said the study offers new information that could help people better understand and protect the endangered elephants as they face increasing threats to their existence. The team’s most striking finding suggests that the overall population of forest elephants is much lower than previously estimated, making their continued survival even more threatened.

The international team’s research provides valuable insights into the population size and social behavior of forest elephants, two important factors that have been left poorly understudied, even as the elephant’s population has dramatically declined over recent decades from human-related activities like habitat loss and poaching.

The new paper was published recently in the journal PLOS ONE. Ting played a senior role in directing the study, which was led by UO graduate student Colin Brand and Gabonese scientist Mireille Johnson and featured various collaborators from the Smithsonian Institution.

It was the elusive nature of the colossal animals that first piqued Ting’s curiosity with the forest elephant. He was studying primates in the jungles of Central Africa and grew intrigued by how little was known about the several-ton mammals that roamed the same forests where he was conducting research.

When he started exploring a research partnership with Johnson, who specializes in forest elephants, he was instantly excited about contributing to a project that could build the knowledge base about the endangered animal.  

“Forest elephants are among the most threatened animals, but their biology and behavior remain poorly understood,” said Ting, who is also a member of the UO’s Institute of Ecology and Evolution. “More information is key to figuring out the best ways to protect them and prevent extinction.”

One of the primary reasons for the limited research effort is because the forest elephants are often grouped with the better-known savanna elephant, but the two-tusked animals are actually quite different, Ting explains.

The two species may share a name, but they differ in many important ways, including their size, physical characteristics like tusk shape and color, reproductive lives, and habitats. Savanna elephants roam open landscapes and the forest elephants stick to more densely wooded areas, where they are harder to study and count.

Ting and the team of researchers aimed to tackle the information gap through their study in Gabon, a region in Central Africa known as a global stronghold for forest elephants. The group focused on forest elephants in the southern Industrial Corridor of the Gamba Complex of Protected Areas, which is a large collection of lands that were preserved to protect biodiversity in southwestern Gabon.

To assess the population size, the researchers counted elephants using a method known as genetic capture-recapture, which involves systematically collecting dung piles and analyzing their genetic composition to match the DNA of each deposit to its owner. It’s like collecting genetic fingerprints for the elephants, Ting explained.

This method was an improvement over prior population assessments, Ting said, which also counted dung piles but could not differentiate piles deposited by the same individual from those deposited by other individuals. This method can lead to overcounting because the same elephant could be responsible for multiple mounds.

The results of the research team’s study show that the elephant population in that area of the Gamba Complex could be 40 to 80 percent smaller than previously suggested. The team estimated that their sample region is home to 754 to 1,502 elephants or 0.47 to 0.80 elephants per square kilometer.

Those data led them to believe the elephant population size across the entire I corridor is between 3,033 to 6,043 elephants based on abundance or 1,684 to 2,832 based on their density — the two different metrics they used to model the population size.

But no matter how they sliced the data, their study showed the forest elephant population to be significantly smaller than previous estimates, which Ting says is especially alarming given the location of their study.  

“Gabon is thought to be a population stronghold of African forest elephants,” Ting explained. “But even our most optimistic results suggest a smaller population size than expected. Our research shows how endangered they really are if a region like this one is so overestimated.”

The researchers also turned to elephant dung to examine the animal’s social behavior, which showed that the animals maintain a much different social structure than savanna elephants, with much wider variation than previously believed.

Ting hopes the study can help inform government officials and conservation groups as they plan future conservation work. He also hopes more research efforts are focused on forest elephants to continue to collect information that could help protect them.

He is conducting more elephant research himself, with a National Geographic grant already secured for a project in western Uganda, where his research group is examining an area where forest and savanna elephants overlap.

“Our study emphasizes the threatened status of forest elephants and demonstrates the need for more research,” Ting said. “It is imperative that known populations are monitored to provide accurate data on the status of these populations and the global forest elephant population as a whole.”

By Emily Halnon, University Communications