IUCN Green Status Assessment reveals uneven recovery for Eastern Gorillas

The International Union for Conservation of Nature has released the first Green Status Assessment for the eastern gorilla offering the most comprehensive evaluation to date of the species’ recovery, ecological functionality, and long-term prospects.

The assessment led by Senckenberg researcher Dr. Jessi Junker was conducted at both the species level and the subspecies level, with separate analyses for the two subspecies: Grauer’s gorilla (Gorilla beringei graueri) and the mountain gorilla (Gorilla beringei beringei).

At the subspecies level, the findings highlight a clear difference: the Grauer’s gorilla has experienced substantial population declines across much of its range over the past two decades, while with regards to the mountain gorilla, population increase demonstrates that sustained, long-term conservation action can lead to recovery.

Rather than a simple contrast between decline and recovery, the findings point to a more nuanced picture: in some areas, particularly certain community-managed forests, Grauer’s gorilla populations have remained stable, demonstrating that sustained protection can prevent further losses.

In the case of mountain gorillas, long-term, intensive conservation has enabled measurable population growth.

“This assessment tells a story of urgency, but also of impact,” said Jessi Junker, lead author of the assessment and researcher at the Senckenberg Museum of Natural History Görlitz, Re:wild, and the Institute for Ape Conservation Science.

“Conservation has made the difference between survival and extinction in some regions. The challenge now is to maintain and scale these efforts.”

Measuring recovery, not only risk

The International Union for Conservation of Nature (IUCN) Red List measures extinction risk, whereas the Green Status framework evaluates how close a species is to being fully recovered across its indigenous range, meaning that populations are viable, distributed across natural habitats, and able to perform their ecological roles.

At the species level, this provides an overall recovery picture for eastern gorillas; at the subspecies level, it reveals important differences between Grauer’s and mountain gorillas.

To conduct the assessment, experts reconstructed the species’ historical range around the turn of the 19th century and divided it into five biologically and geographically meaningful spatial units, reflecting distinct population groups with different threats, conservation histories, and management contexts: four for Grauer’s gorillas in eastern Democratic Republic of Congo and one for mountain gorillas in the Bwindi–Virunga landscape.

Defining these units is essential, as recovery and conservation outcomes vary significantly between landscapes.

Through a series of online and in-person workshops hosted in the species’ range countries, as well as several rounds of consultations, species experts evaluated each spatial unit by examining current population status, major threats such as habitat loss, mining, agricultural expansion, insecurity, and disease risk, as well as the impact of past and ongoing conservation efforts.

The assessment benefited from the contributions and review of more than 60 experts, the majority of whom are based in the range countries of the Democratic Republic of Congo (DRC), Rwanda and Uganda, ensuring that the findings reflect strong regional expertise and on-the-ground knowledge.

“This assessment represents an extraordinary collaborative effort. It stands out for bringing together an exceptionally large number of experts from across the species’ distributional range, and that breadth of expertise makes the findings especially robust”, said Magdalena Cygan, Green Status of Species Officer at IUCN.

Based on this information, the team evaluated different conservation scenarios to estimate how the species would be faring today without past conservation actions, how it is likely to fare if conservation continues, and what could happen if current efforts were reduced or halted.

These scenarios were applied at both the species level and the subspecies level.

Magdalena Cygan added, “The Green Status approach allows us to look beyond extinction risk and ask a deeper question. How close are we to full recovery, and how much has conservation really mattered?”

Grauer’s gorillas: fragile stability in a critically depleted subspecies

At the subspecies level, for Grauer’s gorillas, the Species Recovery Score is 15 percent, placing them in the Critically Depleted category of the Green Status.

Over recent decades, the subspecies has experienced substantial reductions in range and abundance.

It is estimated that the Grauer’s gorilla population has decreased by roughly 60 percent over the past approximately 20 years based on recent survey updates, and fewer than 7,000 individuals remain today.

Yet the assessment also demonstrates that conservation has prevented even more severe losses.

In a few landscapes in DR Congo, including the community-managed Oku Community Reserve and Nkuba Conservation Area, the gorilla populations have remained relatively stable over the past two decades despite ongoing turmoil in the country.

This stability underscores the importance of sustained protection, even in challenging contexts.

“Stable populations in parts of Grauer’s gorilla range show that conservation works,” said Dominique Bikaba, Executive Director of community-based conservation organization Strong Roots Congo.

“Where communities and conservation partners are able to operate effectively, declines can be halted. But these populations remain highly dependent on continued support.”

The Green Status Assessment indicates that past conservation has significantly improved the subspecies’ situation compared to a scenario without protection.

However, these gains remain fragile.

If current conservation efforts were reduced or discontinued, Grauer’s gorilla populations would likely decline rapidly.

While major short-term increases are unlikely due to the species’ long generation time and slow reproductive rate, meaningful recovery remains possible over the long term if conservation efforts are strengthened and sustained.

Mountain gorillas: measured recovery under sustained protection

At the subspecies level, mountain gorillas have a higher Species Recovery Score of 25 percent and are classified as Largely Depleted. Although still far from fully recovered, this reflects measurable population growth over recent decades.

Reduced to fewer than 620 individuals in the 1980s, mountain gorillas now number more than 1,000 individuals in the Virunga Massif and Bwindi Impenetrable National Park.

This increase reflects decades of coordinated conservation, including protected area management, veterinary interventions, transboundary collaboration, and close engagement with local communities.

“The recovery of mountain gorillas is one of the world’s great conservation success stories,” said Felix Ndagijimana, Rwanda Country Director at the Dian Fossey Gorilla Fund.

“It demonstrates that long-term investment, strong law enforcement, and collaboration between governments, NGOs and communities can reverse even steep declines.”

However, the assessment also shows that the recovery achieved so far relies on continued conservation. Without sustained protection and management, recent gains could quickly be reversed.

A shared message: conservation must continue

“The Green Status framework gives us something powerful,” said Andy Plumptre, Head of the Key Biodiversity Areas Secretariat, based in Cambridge, UK.

“It shows not only where we stand, but how much conservation has mattered — and how much more is possible if we stay committed.”

Plumptre adds: “Gorilla conservation is about people as much as wildlife. Where communities, governments, and conservation partners work together, gorillas can persist and even recover.”

The real lesson here is that long-term commitment works, but it must be sustained,” said Liz Williamson, Honorary Professor at the University of Stirling and IUCN Red List Authority Coordinator for great ape taxa.

“Achieving this will require greater levels of long-term funding and sustained investment across the species’ range.”

A roadmap for recovery

The Green Status provides a clear framework for action. By identifying where conservation has worked, where populations remain most vulnerable, and whether recovery is still possible, the assessment offers a baseline for measuring future progress and guiding investment.

This applies at both the species level and the subspecies level, allowing progress to be tracked across scales.

The standardized recovery scores for these gorillas will be updated over time, allowing governments, funders, and conservation partners to track whether efforts are truly moving eastern gorillas up the recovery ladder.

“The Green Status shows that conservation delivers results,” added Jessi Junker. “Now we have a transparent way to measure impact, prioritize resources, and ensure that sustained investment translates into real recovery on the ground.”