2 days ago
What gorillas and a pioneer vet taught us about disease, scarecrows and the future of conservation
It started with itchy gorillas and old scarecrows. It ended with a blueprint for saving both people and wildlife. Yves Vanderhaeghen reports on the One Health initiative launched by the pioneering Ugandan wildlife veterinarian, Dr Gladys Kalema-Zikusoka.
In the misty borderlands of Uganda's Bwindi Impenetrable Forest, villagers fighting to save their banana crops turned to a humble warrior: the scarecrow. They cobbled them together from sticks and discarded clothes, posting them at the edge of their fields to frighten off wild mountain gorillas.
But the scarecrows harboured an invisible threat. They carried disease. And the pioneering vet who figured out the link, Dr Gladys Kalema-Zikusoka, would change the course of conservation, as well as the lives of the villagers. Kalema-Zikusoka will be presenting a keynote address on her work, titled 'Integrating health and people in Gorilla Conservation', at this year's Oppenheimer Research Conference.
The mid-1990s were a boom time for Uganda's fledgling ecotourism industry. Mountain gorillas, once the elusive subjects of Dian Fossey's field notebooks, were becoming international celebrities. They were drawing visitors and dollars to a country eager to rebuild after the regime of Idi Amin, under which teeming wildlife and political opponents were decimated. Kalema-Zikusoka's family did not escape the terror: her father was murdered and her mother was arrested during those years, but she survived.
To meet growing tourism demands, authorities selected gorilla groups living near the park's edge for 'habituation', gradually getting the animals used to human presence. But in doing so, they brought gorillas dangerously close to villages.
Banana plantations proved irresistible. 'And people, of course, get upset because it's their livelihood,' explains Kalema-Zikusoka, 'and so they tend to put dirty clothing on scarecrows to chase away baboons, gorillas and other wildlife.'
But the clothes carried more than the scent of human labour. They carried mites – tiny, infectious stowaways.
Soon after, something strange showed up in the forest.
White, crusty lesions bloomed across the faces and arms of the great apes. Their thick fur thinned. They scratched relentlessly. Mountain gorillas, icons of strength and mystery, were falling prey to an unseen enemy.
Enter Kalema-Zikusoka
Fresh from her training in the UK, Uganda's first wildlife veterinarian had expected to treat the occasional snare wound or parasitic infection, not a mysterious, spreading skin disease. Alarmed, she reached beyond the conservation community, turning to a human doctor friend and asking a deceptively simple question: 'What's the most common skin disease among people living in poverty?'
The answer: scabies.
Confirming the diagnosis took months of careful investigation. Kalema-Zikusoka partnered with wildlife veterinarian and epidemiologist Dr Richard Kock, and together they treated the gorillas with ivermectin, 'which treats scabies, not Covid', she notes in a gentle swipe at anti-vax conspiracy theorists.
Most of the afflicted gorillas recovered. But not all. A tiny infant, weakened by the infestation, was abandoned by its mother and died. 'That group only had four individuals,' Kalema-Zikusoka recalls. 'And we were sending six tourists a day to visit them; more tourists than gorillas. It wasn't ideal.' But mountain gorillas ended up thriving, and by 2018 overall wild populations grew to more than 1,000 (of whom 459 are in Bwindi), and they were removed from the critically endangered list and their status was downgraded to 'endangered'. The Virunga National Park, across the border in the Democratic Republic of Congo and Rwanda, is home to 604 mountain gorillas.
But the real breakthrough wasn't just medical. It was philosophical.
Tracing the human link
Further investigation revealed a stark truth: the gorillas' suffering mirrored that of the human communities living just beyond the forest edge. Villagers struggled without reliable access to clean water, latrines or healthcare. Scabies ran rampant. Waste disposal often meant tossing rubbish into the bush.
'We proved that the disease had come from people,' says Kalema-Zikusoka.
It was a turning point. If human health could compromise gorilla survival, then conservation couldn't focus on animals alone. It had to heal entire ecosystems, including the human ones.
Building a new model: One Health in action
Determined to act, Kalema-Zikusoka founded Conservation Through Public Health (CTPH) in 2003, a nonprofit built around a then-radical idea: you can't protect endangered species without first ensuring the health and wellbeing of the people living beside them.
CTPH's core objectives included improving public health around protected areas, preventing disease transmission between humans, livestock and wildlife, promoting sustainable, community-driven tourism, empowering locals to take ownership of health and conservation and easing human-wildlife conflicts through education and engagement.
At the grassroots level, the changes were practical and profound. Through its Village Health and Conservation Teams, CTPH introduced its '12 Principles of Household Health' to ensure homes were safer, for both people and gorillas.
The principles range from handwashing facilities and using clean latrines and keeping livestock healthy and separate from human areas, to family planning and child spacing.
Family planning? 'Yes, we improve not only sanitation and hygiene. Family planning is a key indicator,' Kalema-Zikusoka explains. 'People used to tell us they had 10 children: five for school, the other five to chase wildlife from the garden. But they couldn't reduce poverty at home.'
CTPH launched a One Health model household initiative, using a colour-coded system, from Red homes, which meet four or fewer principles, to Green homes, which meet more than nine principles.
'Over time we saw an increase from 22% to 58% green households. Volunteers now reach over 50,000 people in 10,000 homes around the national park,' she says.
The stakes were high, for the gorillas and the people. 'Those who don't go to school end up becoming poachers or peasants digging in other people's gardens,' Kalema-Zikusoka explains. 'When you have a huge family, you need more food, more firewood; you go into the forest to survive. That's why we began addressing population, health and environment together.'
Over time, CTPH kept expanding. Nutrition programmes were added to combat hunger-driven poaching. During Covid-19, food security became a focus, and providing fast-growing seedlings helped communities avoid depleting the forest. Furthermore, conservation education efforts helped villagers access and equitably share ecotourism revenue, often a missing piece in previous efforts. In a country where 30% of the population of about 48 million lives below the poverty line, the conservation economy is crucial.
'Our One Health model reaches every home,' says Kalema-Zikusoka. 'Most conservationists would just hold a meeting, and only the elites would attend. But those living right on the park's edge, those chasing wildlife from gardens, the ones causing and suffering the most, they needed to be the biggest beneficiaries.'
A pandemic stress test, and a new chapter
When Covid-19 hit in 2020, CTPH's work became even more critical.
'We built upon the One Health model to mitigate the impact of the pandemic,' says Kalema-Zikusoka. CTPH partnered with the Uganda Wildlife Authority, NGOs, tour operators and communities to prevent transmission between people and gorillas while improving livelihoods through initiatives such as Gorilla Conservation Coffee, a social enterprise supporting farmers near gorilla habitats.
CTPH's organic expansion now addresses 11 of the 17 UN Sustainable Development Goals and is being scaled to other biodiversity hotspots, preventing disease outbreaks and addressing climate change through an integrated, people-centred approach.
The Gorilla Effect: tourism, conservation and care
Today, mountain gorilla populations are steadily increasing, and ecotourism has played a major role.
'Gorilla tourism contributes about 60% of the revenue for the whole Uganda Wildlife Authority,' says Kalema-Zikusoka. 'It funds other parks that can't meet operational costs.'
Around Bwindi alone, more than 70 lodges now cater to visitors eager for a glimpse of habituated gorilla groups. Yet strict guidelines limit encounters: only eight tourists per gorilla group per day.
And the One Health approach ensures tourists don't inadvertently harm the very creatures they come to see.
'It's a real concern that tourists could bring fatal diseases like Covid-19,' she warns. CTPH now promotes responsible tourism: mask-wearing, maintaining a safe distance and encouraging visitors to give back by hiring local porters or buying crafts.
During the pandemic, mask-wearing around gorillas helped dramatically reduce respiratory diseases, especially in Rwanda's high-altitude parks. 'It's a habit we're keeping,' she says.
Health workers are mindful that disease can be carried in both directions. They 'tell people the dangers of eating bushmeat, for example, because you can get zoonotic disease (and it's also illegal). So, they talk about a lot of conservation issues as well as public health issues,' says Kalema-Zikusoka.
'The gorillas in Bwindi pick up worms from people. Whenever they range in community land, they pick up human parasites and livestock parasites. Sometimes they don't make them sick, but sometimes they do. And that's where we have to intervene not only with the gorillas, but with the people and the livestock. We haven't seen any diseases that jump from gorillas to the communities. But they have in other countries, like Ebola in central Africa. Because people there eat gorillas. In Uganda, people don't eat gorillas because it's considered bad luck. It was also considered bad luck to look in the eyes of a gorilla. The Batwa people who lived in the forest never looked in the eyes of a gorilla. They avoided them.
'But when the gorillas cross to DRC, they can get eaten because there they believe if you eat a gorilla, you can become as strong as a gorilla. So, cultural beliefs can also have an impact on zoonotic disease transmission.'
A healthier future for all
Today, the mist still clings to Bwindi's tangled canopy, and the gorillas still roam, but now under careful health monitoring and stronger tourism guidelines. Communities once left behind by conservation are now its champions.
Where a lonely scarecrow once stood, there now stands a network of farmers, health workers and conservationists, united by a shared understanding: survival, for both people and gorillas, depends on each other.
'What started as a veterinary mystery,' says Kalema-Zikusoka, 'became a model for saving species through saving people.'
As she reflects: 'We can't ask people to protect wildlife if they don't have their basic needs met. Healthy people, healthy animals, healthy environment; it's one system.'
In the end, the disease that crossed the forest edge didn't just threaten a species. It connected two worlds, human and wild, and taught them how to heal together. DM
Dr Gladys Kalema-Zikusoka will present a keynote talk, 'Integrating health and people in Gorilla Conservation', at the Oppenheimer Research Conference, which takes place from 15 to 17 October 2025. She is the founder and CEO of Conservation Through Public Health and has published an autobiography, Walking With Gorillas: The Journey of an African Wildlife Vet.
