Looking Back at How Far We’ve Come

On a remote mountain in Africa’s oldest national park, four rescued gorillas are rewriting what is possible for their species.

Isangi, Lulingu, Mapendo, and Ndjingala were orphaned by the illegal wildlife trade and spent years recovering at the Gorilla Rehabilitation and Conservation Education (GRACE) Center—the world’s only sanctuary dedicated to Grauer’s gorillas. Today, they are healthy, fully integrated into a wild family group, and helping change the future of one of the world’s smallest and most isolated Grauer’s gorilla populations.

In May 2025, GRACE and our partners announced a historic reintroduction to Mt. Tshiaberimu in Virunga National Park, Democratic Republic of the Congo (DR Congo). They became the first rescued Grauer’s gorillas ever rewilded from the GRACE sanctuary and successfully integrated into a wild population. Their arrival increased the critically small Mt. Tshiaberimu population from eight to 12 gorillas.

Grauer’s gorillas, also known as eastern lowland gorillas, are found only in eastern DR Congo. Their population has declined by more than 60% since the mid-1990s, with fewer than 6,800 believed to remain in the wild. Every individual matters—and every successful birth could help strengthen the future of this vulnerable population.

Their new home lies within Virunga National Park, a UNESCO World Heritage Site and the only national park in the world that protects both Grauer’s gorillas (Gorilla beringei graueri) and mountain gorillas (Gorilla beringei beringei). Once at serious risk of disappearing, the Mt. Tshiaberimu population now has renewed hope.

Isangi, Lulingu, Mapendo, and Ndjingala are also giving conservation teams an unprecedented window into this little-known population—and showing encouraging signs that new births may be ahead.

Ndjingala, one of four female Grauer’s gorillas rewilded from the GRACE sanctuary, cuddles close to juvenile Kavango, a member of Mwasa’s family group on Mt. Tshiaberimu

October 2024 — The Journey to Mt. Tshiaberimu

The journey to Mt. Tshiaberimu began years before the helicopter lifted off.

Rescued from the illegal wildlife trade between 2010 and 2016, Isangi, Lulingu, Mapendo, and Ndjingala each came to GRACE for long-term rehabilitation. Mapendo and Ndjingala were among the first gorillas to arrive at the sanctuary, while Lulingu was just 18 months old when she entered GRACE’s care.

The four females became part of a cohesive social group and learned to navigate GRACE’s expansive forest habitats, where they could forage, climb, build nests, and practice the natural behaviors essential for life in the wild. Throughout their rehabilitation, they received daily care and monitoring from expert Congolese caregivers who understood their health, personalities, social bonds, and individual needs.

From Years of Preparation to Lift-Off

After years of preparation, the four females arrived on the remote, forested mountain by helicopter — the same helicopter that once carried some of them to safety at GRACE. Their selection for rewilding followed more than a decade of rehabilitation and over five years of intensive planning. 

The project was guided by GRACE, Virunga National Park, Gorilla Doctors, Re:wild, ICCN, and an international project advisory committee of more than 20 experts, following IUCN Best Practice Guidelines for great ape reintroduction.

Late 2024 — First Days in the Rewilding Facility

At Mt. Tshiaberimu, project partners built a second gorilla housing facility based on the GRACE sanctuary model. The team expected the transition to take time, possibly even a year or more.

Mt. Tshiaberimu is higher in elevation than GRACE, with colder temperatures, different terrain, and a wild gorilla diet made up largely of bamboo. To help the females adjust, GRACE staff even brought a truckload of familiar vegetation from GRACE so that Isangi, Lulingu, Mapendo, and Ndjingala would have favorite foods available during the acclimation period.

But the gorillas surprised everyone. They had other plans.

They quickly began exploring, foraging, and adapting to their new environment with remarkable speed. The females began spending their days in the enclosed forest habitat. Soon, they were less interested in coming inside to sleep at night. What the team expected might take months began happening in a matter of weeks.

Then, in December, something even more exciting happened: Mwasa appeared.

Meeting Mwasa

Mwasa, a wild silverback, began showing interest in Isangi, Lulingu, Mapendo, and Ndjingala. The females were equally interested in him. They approached the fence line, watched him closely, and spent increasing time near him.

Mapendo, known for her intelligence and independent nature, made her interest especially clear. She began finding branches and attempting to use them against the fence. It was a signal the team could not ignore.

GRACE caregivers, advisors, and members of the Project Advisory Committee were encouraged by the females’ behavior with Mwasa. They showed appropriate social behavior during their first interactions with him — a critical sign that they were ready for the next step.

After careful observation and expert review, the team determined it was safe to give the females access to Mwasa. 

December 3, 2024 — The Big Day

On December 3, 2024, the team removed portions of the fence between the rewilding facility and Mwasa’s territory.

Isangi, Lulingu, Mapendo, and Ndjingala voluntarily left the rewilding facility and entered the forest with Mwasa. From that moment forward, they remained with him in the wild.

It was the milestone the team had worked toward for years: four rescued, rehabilitated Grauer’s gorillas joining a wild silverback in their native range.

Isangi, Lulingu, Mapendo, and Ndjingala crossed a historic threshold, voluntarily leaving the rewilding facility and joining Mwasa’s group in the wild

For GRACE caregivers, many of whom had cared for the females since they were young, it was an unforgettable moment — the beginning of a new chapter for the gorillas, Mt. Tshiaberimu, and the future of this critically endangered species.

“My greatest pride in this process of transferring the gorillas from GRACE back into the wild is that everything went well. It shows how well the females were prepared for reintroduction. They have adapted to the Tshiaberimu forest, they are in good body condition, they are finding their own food, and they are building their own nests. They are behaving as wild gorillas should.” – Dalmas Kakule Syangeha, GRACE Animal Care Manager

Early 2025 — Becoming a Wild Family

When Isangi, Lulingu, Mapendo, and Ndjingala joined Mwasa, they were not only joining a silverback. They were joining an existing family group.

Mwasa’s group already included adult female Mwengesyali and her juvenile, Kavango. The four females from GRACE successfully integrated with them, showing strong signs of adapting quickly to their new environment.

Following Mwasa’s lead, the group has been observed foraging on native plants, building nests, traveling through the forest, and maintaining healthy body condition. Remarkably, the four rewilded females now eat more plant species than any gorillas on Mt. Tshiaberimu, including foods they had never encountered before, such as bamboo leaves and bamboo shoots.

The team has also observed copulation behaviors between Mwasa and the rewilded females! This is an encouraging sign and gives hope for a new generation of Grauer’s gorillas on the mountain. 

Daily monitoring by GRACE caregivers, Gorilla Doctors, and Virunga staff continue to document behavior, diet, ranging, nesting, health, and social dynamics. Gorilla Doctors also conduct routine non-invasive health monitoring, collecting fecal samples for both groups of gorillas on the mountain. 

Meet the Neighbors: Katsabara’s Group

Mwasa’s group was not the only gorilla family on Mt. Tshiaberimu.

Elsewhere on the mountain lived another group led by silverback Katsabara. His group included two adults, Mukokya and Ndekesiri; one juvenile, Espoir; and Ndekesiri’s young infant Kyusa.

The presence of two gorilla groups on the mountain is part of what makes monitoring at Mt. Tshiaberimu so important. Each group has its own social structure, ranging patterns, and relationships within the landscape. GRACE caregivers, Virunga rangers, and Gorilla Doctors continued monitoring both groups to better understand their health, movements, and behavior.

June 2025 — Loss Within Mwasa’s Group

As the rewilded females settled into life with Mwasa, the Mt. Tshiaberimu population faced the realities of a small, aging population. In Mwasa’s group, Mwengesyali, an elderly female estimated to be over 30 years old, died of natural causes in June 2025. 

Mwengesyali’s infant Kavango remained with the family group. Monitoring teams recorded Mwasa devotedly caring for Kavango, sharing a nest together each night. During the day, Isangi, Lulingu, Mapendo, and Ndjingala spent time with Kavango too, playing with and paying close attention to the youngster.

That same month, the team also documented the first interactions between Mwasa’s group and Katsabara’s group. These observations provided important insights into the integration and behavior of the rewilded females as they experienced natural social dynamics within a wild population.

Late 2025 — A Year of Adaptation

By late 2025, Isangi, Lulingu, Mapendo, and Ndjingala were well established within their new wild home. Their diets increasingly reflected those of the mountain’s wild gorillas, while ongoing ranging and feeding studies became the longest-running scientific data collection on the Mt. Tshiaberimu population in recent years.

Then came another encouraging sign: positive pregnancy tests.

Supporting the recovery of this small, isolated population had been a central goal of the rewilding effort from the beginning. As pregnancy monitoring began, the possibility of a new generation offered hope that this historic effort was moving closer to that goal.

February 2026 — A Hopeful Birth

In late February 2026, Ndjingala gave birth—an extraordinary and deeply hopeful milestone. Her baby appeared healthy, and Ndjingala immediately showed attentive maternal behavior, holding the newborn close and responding instinctively to its needs.

The moment carried particular significance because Ndjingala had been rescued as an infant after being taken from her own family. Like many gorillas orphaned by the illegal wildlife trade, she had missed the opportunity to grow up within her natal group and learn by watching experienced mothers. Until she gave birth, the team could not know how those early losses might affect her ability to become a mother herself.

More than 14 years after arriving at GRACE as a rescued baby, Ndjingala was back in the wild, bonding with and caring for a baby of her own.

March 2026 — A Difficult Turn

In early March 2026, regional insecurity temporarily prevented monitoring teams from accessing the gorillas for a few days. 

Once they were able to return to the forest, the team noticed trails that indicated the two gorilla groups had come close to each other. Upon finding the Katsabara group, aging silverback Katsabara was observed with physical injuries. Mukokya, Espoir, Ndekesiri and Kyusa were found wandering at a distance on their own. Monitoring teams concluded there had been a physical interaction between Mwasa and Katsabara. 

The next day, the monitoring team found Katsabara had succumbed to injuries from his interaction with Mwasa. Sadly, they also discovered that Ndjingala’s infant had died. The exact cause of the infant’s death is unknown.

While losses are expected in wild gorillas, this was a heartbreaking time for the entire team.

April and May 2026 — Continuing Learning

In the weeks that followed, the gorillas began adjusting to the changes within their groups. Mukokya, Ndekesiri, Espoir, and Kyusa continue ranging independently from Mwasa’s group. Monitoring teams continue to follow them closely, observing how their social dynamics evolve over time.

Mwasa’s group remains stable. Isangi, Lulingu, Mapendo, and Ndjingala range, feed, and rest alongside Mwasa and Kavango as an established wild family group. Kavango is spending increasing amounts of time near Ndjingala, one sign of the relationships continuing to develop within the group.

Isangi, Lulingu, Mapendo, and Ndjingala remain central to the future of this small gorilla population. Daily monitoring tracks their health, behavior, ranging, diet, social dynamics, and reproductive status. Additional positive pregnancy tests offer hope for new births on the mountain.

Even now, as project partners adapt monitoring protocols in response to Ebola, the work moves forward. GRACE caregivers, Virunga rangers, Gorilla Doctors, and advisors work together to observe, learn, and respond to each new chapter of the gorillas’ lives in the wild.

The Story Continues…

The story of Isangi, Lulingu, Mapendo, and Ndjingala is still unfolding—shaped by courage, science, resilience, and hope.

These four females have already changed the future of Mt. Tshiaberimu. Their presence has strengthened one of the world’s most fragile gorilla populations and created new possibilities in a place where extinction once seemed likely.

 

The translocation and population reinforcement is the culmination of a more than five-year rewilding process led by GRACE, Virunga National Park and local communities. Read the joint press release HERE.