Environmental DNA Revolutionizes Wildlife Conservation in Rwanda’s Protected Areas

MUSANZE, Rwanda — In the mist-shrouded forests of Rwanda’s Volcanoes National Park, a guide communicates with endangered golden monkeys using grunts and clicks, signaling his peaceful intent—a common practice in this biodiverse region. Yet even the park’s largest residents, the mountain gorillas, often remain hidden by steep ridges and dense vegetation, prompting scientists to adopt innovative detection methods.

Environmental DNA (eDNA) technology, which identifies species through genetic material like fur or feces left in soil and water, is reducing the need for disruptive human surveys. Traditionally used in marine conservation, the method is now being deployed in Rwanda by the African Wildlife Foundation in partnership with the government to catalog all species in the country, a crucial step for protecting biodiversity threatened by climate change and population growth.

“We selected eDNA as a new technology to bring solutions and to complement existing methods used in ecological monitoring,” said Patrick Nsabimana, the foundation’s country manager for Rwanda.

Conventional biodiversity monitoring has long depended on camera traps and ranger observations, but these face challenges in the rugged Virunga mountains that span Rwanda, Uganda, and Congo, where border insecurity can also limit access. Nsabimana noted that eDNA offers a cost-effective approach for large ecosystems; samples collected from accessible sites like downstream ponds can reveal genetic traces from animals higher up, allowing for broad species detection from a single sample.

“With one sample, you can detect multiple species—mammals, birds, amphibians, and many others,” explained Deogratias Tuyisingize, a biodiversity researcher with the Dian Fossey Gorilla Fund, which is also involved in the project. He emphasized that combining traditional fieldwork with eDNA is essential, as steep terrain previously caused scientists to miss species. Improved species location data also enhances anti-poaching patrols.

This capability is especially valuable as Rwanda expands its national parks by restoring agricultural land. “We can see how species are colonizing these sites over time,” Tuyisingize said, allowing conservationists to gauge success through the return of rare species and to spot early signs of invasive ones.

However, eDNA has limitations. It cannot reliably estimate animal population sizes, as DNA can persist long after a species departs. Processing samples locally is another hurdle; initial samples had to be sent to Europe for analysis. Additional challenges include maintaining cold storage, preventing contamination, and bridging data gaps. Africa’s genetic reference libraries are relatively limited compared to those in Europe and America, complicating DNA sample matching, according to James Munyawera of the Gorilla Fund. Researchers are now constructing region-specific databases to address this.

The project in Volcanoes National Park is also training local community members and rangers to collect samples, fostering broader participation in conservation monitoring.

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