For almost four years, the teams of researchers traveled by boat up winding rivers, setting up base camps inside dense rainforests for weeks or months at a time as they searched for signs of elusive forest elephants and bonobos. Trekking deep into Salonga National Park, a sprawling tract of protected jungle in the heart of the Democratic Republic of Congo (DRC), the researchers set up cameras and held their breath, hoping to find evidence that populations of the two species hadn’t fallen in recent years.
Now, after years of meticulous and grueling work, the research teams have an answer. Inside Salonga, which spans more than 36,000 square kilometers (14,000 square miles) — an area larger than the total land mass of neighboring Rwanda — preliminary results indicate relatively stable populations of the two animals. According to a March press release from WWF, the multi-year study estimates the park is home to around 1,600 forest elephants (Loxodonta cyclotis) and 15,000 bonobos (Pan paniscus).