Tracking Wildlife Without the Footsteps: How DNA in the Wild Helps

In the forests of Rwanda’s Volcanoes National Park, steep ridges and thick mist often hide mountain gorillas from human eyes. Scientists used to rely on camera traps and ranger patrols to track these endangered animals, but rugged terrain and security risks in the border area made this difficult. Now, a new approach is being tested—one that doesn’t require seeing the animals at all. Instead of waiting for gorillas to trigger motion sensors, researchers are collecting environmental DNA (eDNA) from soil and water. This genetic material, like fur or droppings, can reveal which species are nearby without disturbing them. The method was first widely used underwater to study marine life, but now it’s being adapted for land conservation. In Rwanda, environmental groups are working with the government to build a countrywide species database, helping monitor biodiversity amid threats like climate change and habitat loss. The project combines old and new techniques. Traditional methods like camera traps and ranger reports still play a role, but eDNA fills gaps, especially in hard-to-reach places. “There are areas we can’t easily access, so we might be missing whole species, ” said a biodiversity researcher involved in the work. By testing water downstream from gorilla habitats, for example, scientists can detect multiple animals—mammals, birds, and even amphibians—with just one sample.This approach has other benefits too. Knowing where endangered species live helps anti-poaching teams focus their patrols. It also tracks how wildlife moves into newly restored habitats, like former farmlands turned back into parks. “We can watch species slowly return to these places, ” the researcher noted, adding that early signs of invasive species can also be spotted before they become a problem. But eDNA isn’t perfect. It can’t tell researchers exactly how many animals are in an area, and DNA traces can stay in the environment long after an animal has moved on. There are logistical hurdles too—some early samples had to be sent to Europe for analysis because Rwanda lacked the lab equipment. Cold storage and contamination risks also complicate the process. Another challenge is Africa’s limited genetic reference libraries. Most data comes from Europe and America, making it harder to identify local species. To fix this, researchers are building databases specific to African wildlife. Meanwhile, the project is training local residents and rangers to collect samples, turning communities into active participants in conservation.