Tanzania’s Gombe National Park’s chimpanzees plunge by nearly 50 per cent since Jane Goodall’s era
In the forest where Jane Goodall changed science forever, one of the world’s most famous chimpanzee populations is quietly shrinking — and fighting to survive.
THURSDAY June 18, 2026
By Adam Ihucha
The Tranquillity News Correspondent, Gombe National Park, Tanzania
Before dawn, the forest still sounds much as it always has.
A distant chimpanzee call rolls through the canopy above Lake Tanganyika, answered moments later from another ridge.
The sounds drift across steep green hills where mist settles among the trees.
But there are fewer voices now.
In Gombe National Park, one of the most closely studied chimpanzee populations on Earth has fallen by nearly half since the 1960s.
Where roughly 150 chimpanzees once lived, conservation authorities estimate that about 77 remain today.
The decline is measured not only in numbers, but in lineage.
These are the descendants of the same chimpanzee communities observed by Jane Goodall when she arrived in 1960 and documented chimpanzees making and using tools — a discovery that reshaped scientific understanding of the relationship between humans and other animals.
More than six decades later, that same population remains.
But it is smaller, more fragmented and increasingly exposed to pressures that threaten its long-term survival.
A forest that changed science
Gombe is small by any standard — just 33.6 square kilometres of steep slopes pressed between the escarpment and the waters of Lake Tanganyika.
Yet, its scientific significance is enormous.
It was here that researchers documented chimpanzees hunting, forming alliances, defending territories, and caring for their young.
The park became one of the most important field sites in the history of animal behaviour research.
Today, however, Gombe is forcing scientists and conservationists to confront a different question: Whether a small, isolated population can survive in a rapidly changing landscape.
The Tanzania National Parks (TANAPA) Veterinary Specialist, Dr Jane Mwandupe, said long-term monitoring shows a population that has demonstrated both resilience and vulnerability.
“Long-term monitoring reveals a population that has experienced both resilience and vulnerability,” Dr Mwandupe said.
The slow disappearance
The decline has not been sudden.
According to TANAPA records, the population remained near 90 individuals through much of the past decade, standing at 88 in 2016 before rising briefly to 94 in 2017.
Numbers then gradually declined to 84 in both 2020 and 2021, 85 in 2022, 83 in 2023 and approximately 77 in 2024.
One of the most significant developments has been the collapse of the Kalande community.
Once recognised as a distinct chimpanzee group within the Gombe ecosystem, Kalande has been reduced to only a handful of individuals.
Dr Mwandupe said conservationists attribute much of the decline to the long-term effects of Simian Immunodeficiency Virus (SIV), which affected the community during the 1990s, followed by repeated outbreaks of respiratory illness.
“The remaining females have increasingly integrated with neighbouring communities, leaving the former Kalande range largely unoccupied,” she said.
Disease, conflict, and a shrinking world
Between 2020 and 2024, researchers recorded 20 chimpanzee deaths in and around the park.
Most were linked to infectious disease, particularly respiratory illnesses.
Other deaths resulted from conflicts between chimpanzee groups competing for territory, while some causes remained undetermined.
Long-term monitoring reveals a population that has experienced both resilience and vulnerability,” Dr Jane Mwandupe, Tanzania National Parks Veterinary Specialist.
Historical records from Gombe indicate that more than half of all chimpanzees’ deaths have been associated with disease, while about one-fifth have resulted from inter-community conflict.
Researchers believe the park’s limited size contributes to both challenges by increasing contact among chimpanzees and intensifying competition for space and resources.
Yet, amid the decline, scientists have identified encouraging signs.
Between 2020 and 2024, researchers documented 21 births across the park, most within the Kasekela and Mitumba communities.
Dr Mwandupe noted that chimpanzees reproduce slowly, with females typically giving birth only once every four to six years.
“As a result, every surviving infant represents an important contribution to the future recovery of the population,” she said.
The continued births suggest that the population retains the biological capacity to stabilise if existing conservation measures can be sustained.
The edge of survival
Gombe’s isolation is part of its beauty — and part of its vulnerability.
Unlike larger ecosystems that allow for migration and population exchange, Gombe is constrained by geography and surrounding human settlement.
Outside the park, forest fragmentation, agricultural expansion, and encroachment have steadily reduced habitat connectivity.
The most critical remaining link is the Gombe-Kagunga corridor, a patchwork of village forests that allows chimpanzees to move between fragmented habitats and maintain genetic diversity.
Conservationists estimate that about seven chimpanzees currently inhabit the corridor.
Without it, scientists warn, Gombe’s population faces increasing ecological and genetic isolation.
Building a future beyond the park
TANAPA Chief Conservation Commissioner Musa Nasoro Kuji said government conservation efforts have increasingly focused on protecting the corridor and strengthening habitat connectivity.
“The government authorities have repeatedly stressed the importance of strengthening legal protection for the corridor and ultimately incorporating it into the wider protected-area network,” Mr Kuji said.
In response to growing threats, Tanzania and its conservation partners have expanded a range of interventions aimed at securing the future of the species.
Mr Kuji said park teams conduct daily monitoring of chimpanzees’ health and behaviour, alongside biannual monitoring within the Gombe-Kagunga corridor.
Additional measures include disease surveillance systems, habitat protection programmes, fire prevention initiatives, climate and vegetation monitoring, strict visitor health protocols, and conservation education programmes.
Local communities have also become central to the strategy through alternative livelihood initiatives designed to reduce pressure on forest resources.
Among the most successful are beekeeping projects involving hundreds of hives in villages surrounding the park.
Authorities have also intensified enforcement efforts against illegal encroachment.
A major operation conducted in 2025 resulted in the demolition of 97 unauthorised structures, the destruction of 12 livestock enclosures, and the arrest of 12 suspects.
Authorities reported that approximately 75 per cent of those detained were foreign nationals.
Mr Kuji described the intervention as a critical step toward restoring ecological integrity in a landscape essential to chimpanzee survival.
A global symbol at the crossroads
For scientists and visitors alike, Gombe is more than a research site. It is a symbol of the connection between humans and their closest living relatives.
The park’s chimpanzees continue to reproduce, maintain social bonds, and adapt to changing conditions.
Mothers still nurse infants in the forest canopy, and young chimpanzees continue to learn the behaviours that define their communities.
But the future remains uncertain.
The decline from roughly 150 chimpanzees in the 1960s to about 77 today underscores the scale of the challenge facing one of the world’s most celebrated wildlife populations.
Even so, conservationists see reasons for cautious optimism.
Ongoing births, strengthened law enforcement, habitat restoration, and growing community participation are helping to stabilise a population that remains under pressure.
For now, the forests above Lake Tanganyika still echo with the calls of Gombe’s chimpanzees.
They are fewer than they were in Jane Goodall’s era, but they have not fallen silent.
The question now is whether decades of science, conservation, and community engagement can ensure that they never do.
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Adam Ihucha is a prominent Tanzanian journalist and author recognized for his extensive coverage of tourism, wildlife conservation, and economic issues in East Africa. Based in Arusha, he serves as a senior correspondent for The Tranquility News and is a long-time contributor to eTurboNews (eTN), where he provides global insights into Tanzania's travel industry.
Throughout his career, Ihucha has written for several major publications, including The Guardian (Tanzania) and The EastAfrican. His work frequently highlights the intersection of environmental conservation and economic development, covering critical topics such as anti-poaching initiatives, national park management, and regional trade within the East African Community. His journalism is noted for its advocacy for sustainable tourism and its role in documenting the achievements of Tanzania's tourism sector.
Email contact: ihucha@tranquilitynews.com
