No room for African apes. That appears to be the verdict of a new study published in the journal Diversity and Distributions predicts massive range declines of Africa’s great apes – gorillas, chimpanzees, and bonobos – due to the impacts of climate change, land-use changes, and human population growth.
Sometimes there is no sugar-coating news. But one of our strongest beliefs at GLOBIO is news is not negative, it’s merely information with which we determine if the outcome is negative or positive.
Last month, a stark warning was issued, information we ignore at the peril of all apes like us.
Information Alert: African Great Apes Will Soon Have Almost No Habitat Left, Scientists Warn
For the past half-century, the following facts have been being delivered: human population is increasing, we are consuming beyond sustainability, we are driving anthropogenic climate change, we are inflicting dramatic accelerating biodiversity loss. Great apes are the canaries in the global coal mine, and the song they are singing is clear: Humans are driving the extinction of our closest relatives on planet Earth, and if we don’t change our behavior, we may be the last ape like us standing.
Initially the worst-case scenario, researchers in the report predict a 94 percent loss of great ape habitat in Africa by 2050. Even if we get our act together before then, reducing our fossil fuel emissions and keeping ecosystems protected, models show gorillas, chimpanzees, and bonobos will likely lose 85 percent of their range in Africa in the next three decades. No matter which scenario ends up coming true, roughly half of all habitat loss could occur in protected areas, like national parks.

Tropical rainforest cleared by a local farmer — slash and burn fragmentation — near Ebo Forest, Cameroon

“Importantly, massive range loss is widely expected outside protected areas, which reflects the insufficiency of the current network of protected areas in Africa to preserve suitable habitats for great apes and effectively connect great ape populations.” Joana Carvalho, lead author of the study. Above: Like termites eating away at the fringe of forests, local slash and burn farming practices while initially minor create gaps in the continuity of the rainforest canopy terminating the movement of apes and primates. Eventually, fragmentation creates isolated islands of vegetation trapping apes genetically, increasing the impact of disease as well as facilitating the ease of bushmeat hunters to slaughter remaining individuals.
At this point, even the best-case scenario is not looking great. The protected areas we have designated for great apes in Africa simply aren’t cutting it. In fact, they are all too often being cut into. Often called paper-parks, lack of funding, lack of protection, and lack of political commitment (often undermined by corruption).
Going forward, multiple models predict all great apes in Africa are likely to experience massive range losses (Asia’s ape, the three species of orangutan have already experienced massive range loss), regardless of whether protected areas remain in place or not.
Currently, many African apes live outside of these boundaries, in areas that are particularly suitable for farming or industrial oil palm conversion.
African Great Apes in Unprotected Areas,
-
64 percent of mountain gorillas,
-
75 percent of Grauer’s gorillas
-
91 percent of Cross River gorillas,
-
80 percent of bonobos,
-
90 percent of Nigeria-Cameroon chimpanzees,
-
80 percent of eastern chimps, and
-
80 percent of central chimps.
“The fact that the greatest range losses are expected to occur outside protected areas reflects the insufficiency of the current network of protected areas in Africa to preserve suitable habitats for great apes and effectively connect great ape populations,” says Joana Carvalho,
Climate Change
This first-of-its-kind study quantifies the joint effects of climate, land-use, and human population changes across African ape ranges for the year 2050 under best- and worst-case scenarios. “Best case” implies slowly declining carbon emissions and that appropriate mitigation measures will be put in place. “Worst case” assumes that emissions continue to increase unchecked – business as usual.
Under the best-case scenario, the authors predict that great apes will lose 85 percent of their range, of which 50 percent will be outside national parks and other areas protected by legislation. Under the worst-case scenario, they predict a 94 percent loss, of which 61 percent will be in areas that are not protected.
Climate change, like disease, doesn’t conform to political boundaries and becomes a compound effect. As our planet warms and vegetation landscapes shift, apes like many species are slow to reproduce and require niche environments.
Such migration could also drive great apes out of protected areas, putting their populations at even greater risk. In fact, a series of new models estimate that future ranges for chimps, gorillas, and bonobos will shift mostly towards unprotected areas, which are subject to farming, mining, logging, hunting, and urban development.
We have a considerable body of evidence illustrating how we got here, but as the study highlights, “few studies have only examined future effects of climate change or human disturbances, but how future synergistic interactions among climate, land use and human population changes will affect African apes and their habitat has been largely unexplored.”
Nowhere To Run, Nowhere To Hide
While climate change will no doubt make some habitats less attractive to great apes, it can also create new habitats. A few decades however is not enough. Apes don’t breed like rabbits. Low birth rates and critical multi-year infant development mean slow population growth and slower expansion. If chimpanzees don’t shift their habitats, for instance, the new study suggests more than three-quarters of their range will be lost under future scenarios.
Gorillas may be at the highest risk, as many survive in virtual islands of habitat. Mountain gorillas (Uganda, DRC, and Rwanda) and Cross River gorillas (Cameroon), for example, have virtually nowhere else to go. Even in the best-case scenario, current models found that these two groups of great apes are likely to experience a complete loss of suitable habitat with no new suitable habitat to which they can escape.

Mountain Gorillas may be at the highest risk with already limited habitat and no corridors to additional space — the threat of climate change, disease, and genetic inbreeding are serious concerns.
While nearly a third of the world’s population, many the poorest, live in the tropics shared by great apes, it remains Western resource consumption that an ever-increasing threat. “The global consumption of natural resources extracted from great ape ranges is one of the main causes of great ape decline,” says ecologist Hjalmar Kühl from the Max Planck Institute. “All nations that benefit from these resources have a responsibility to ensure a better future for great apes, their habitats, as well as the people living in them by advancing a more sustainable economy.” This means looking more deeply at global conservation cost-sharing schemes. Currently, the “blockchain” economic modeling already in place in the tech industry, for example, could play a key role in accurately valuing habitats and species for their existence. It has long been seen, by humans, that a species’ value is only if it can be monetized.
Habitats Need To Be Connected
The authors of the study were clear all is not lost, but intelligent planning and action is paramount and urgent, “…habitat suitability models could help in the establishment and management of protected areas. In addition, maintaining and establishing linkages and corridors between habitats predicted to be suitable in the future will be critical for the survival of the African great apes. Land use planning and climate change mitigation measures urgently need to be integrated…” One such project in the Loma Mountains — the Loam Chimpanzee Survival Project. There GLOBIO is working with our Program Partner Tacugama in Sierra Leone to do just that: protect, reclaim and expand ape habitat by creating tree canopy corridors, and reforesting protected area perimeters where slash and burn agriculture has cause forest fragmentation.

Park boundary clearly visible with bamboo forest on one side and farming from the eastern slope of Mt Karisimbi on the other – Parc National Des Volcans, Rwanda. Increasingly protected areas great apes are becoming isolated islands. Mountain gorillas in the Virunga Mountains of Central Africa are the clearest example of isolated islands — with little opportunity to be connected via corridors to viable habitat.
GLOBIO’s Role In The Decade Ahead
This study doubles down on the need for GLOBIO and its Program Partners to intensify the work we are doing and have planned. The four Focal Regions outlined in our 2021-2024 Strategic Plan target the very heart of the habitat loss outlined in the study. If we don’t all commit to conserving and expanding these critical regions, by the end of the century, there’s a very real chance humans will be the only great ape left. That was the driving concern as we worked through developing a new Strategic Plan for the coming decade. Our work filming and interviewing folks on the frontline over the past decade was alarming and clear — time is critical, time is of the essence if we and all other species are to have a future that resembles in any fashion the one we have been living in.
The clearest warning sign was that the scale of change demands many hands. The days of do-good NGOs going it alone with their own ideas is over; we all have a vital stake in this. The new work will require a huge paradigm shift for many, the logos and egos need to be left at the door, and the business of repairing, replanting, and rewilding has to begin immediately alongside intelligent forward planning, long-term biodiversity sustainability priorities, and education and awareness. This isn’t 1950’s rocket science, we now know how to build rockets, send them safely into space and bring them back. Biodiversity—landscape conservation is in the 1950s, but what we did then we can do now.

Existing Protected Areas Are Not Enough
GLOBIO is working with Program Partners like Tacugama in Sierra Leone to protect, reclaim and expand ape habitat by creating tree canopy corridors, and reforesting protected area perimeters where slash and burn agriculture has cause forest fragmentation. One such project in the Loma Mountains — the Loam Chimpanzee Survival Project — targets community engagement and protection of Sierra Leone’s largest single population of Critically Endangered Western chimpanzees: recently declared the national animal, the first great ape so designated by any nation.
GLOBIO approach is illustrated through our planning and work with Program Partners like Tacugama in Sierra Leone to protect, reclaim and expand ape habitat by creating tree canopy corridors, and reforesting protected area perimeters where slash and burn agriculture has cause forest fragmentation, develop renewable, sustainable forest buffers for utilization by local Sierra Leonians, and creating sustainable livelihoods from the health of the shared habitat. One such project in the Loma Mountains — the Loam Chimpanzee Survival Project — targets community engagement and protection of Sierra Leone’s largest single population of Critically Endangered Western chimpanzees: recently declared the national animal, the first great ape so designated by any nation.
Information in this post was drawn from the original study published in the journal Diversity and Distributions
.