Climate Change

Climate change threatens African great apes habitats, may witness frequent extreme climate events in future

Majority of ape sites would be subject to a high frequency of heatwaves, finds new research

By Susan Chacko
Published: Friday 01 March 2024
Bonobos are more sensitive to climate change impacts of all great apes, the study said. Photo: iStock

The warming planet is threatening the habitats of the great apes of Africa, a new study found. While the habitats have already witnessed impacts of climate change, the primates are likely to be subjected to extreme events in the future, said the research, published in journal PLOS Climate, February 28, 2024.

Researchers used climate data to calculate climatic variables for 363 ape sites covering 21 countries across Africa for the past (1981–2010). They also looked at future exposure to climate change impacts using two scenarios for the near term (2021–2050) and long term (2071–2099).

Among the two scenarios, one witnesses robust mitigation measures, aiming for global temperatures to stay below a 2 degrees Celsius increase by 2100. In contrast, the other one represents a scenario with moderate emissions, where a lack of additional mitigation efforts could result in global temperatures rising up to 3°C by the end of century.

The study was led by Razak Kiribou of Haramaya University in Ethiopia, who examined the exposure of African apes to six types of extreme events (crop failure, drought, heatwave, river flood, tropical cyclone and wildfire). All of these have been shown to have a negative impact on African apes.

Historic data revealed that 171 sites had positive temperature anomalies for at least nine of the previous 10 years, with the strongest anomalies (up to 0.56°C) estimated for eastern chimps. Climate projections suggested that temperatures would increase across all sites, while precipitation changes are more heterogeneous. 

The researchers predicted a future increase in heavy precipitation events for 288 sites, as well as an increase in the number of consecutive dry days by up to 20 days per year, with the highest increase expected for eastern gorillas. 

In the future, all sites will be frequently exposed to wildfires and crop failures, which may have an indirect impact on apes due to increased deforestation, the paper said. Heatwaves are expected to affect 84 per cent of sites, while river floods will affect 78 per cent. 

Tropical cyclones and droughts were only forecast for specific locations in western and central Africa.

Bonobo (gracile chimpanzee) sites covered the narrowest temperature range. This indicated a “potentially lower physiological tolerance that might make bonobos more sensitive to climate change impacts,” the study pointed out.

High temperatures could lead to reduced physiological performance — energy and time allocated to thermoregulation lead to physiological and behavioural trade-offs which can put constraints on the time budget and reduce survival and fertility. Extremely high temperatures can also lead to direct mortality. Lower precipitation, on the other hand, leads to lower availability of standing water sources and as a consequence, dehydration.

All of Africa’s great apes — chimpanzees, gorillas and bonobos — are already classified as endangered or critically endangered by the International Union for Conservation of Nature.

A June 2021 study published in journal Diversity and Distributions warned that Africa’s great apes could lose more than 90 per cent of their habitat within the next 30 years due to the combined pressures of human population growth, resource extraction and the climate crisis.

The prevalence of exposure of ape sites to climate change impacts stresses the need to plan conservation action plans and implement conservation measures that will increase ape resilience to climate change.

In areas with water scarcity, the creation of additional water sources or the protection of such sources specifically for apes would be a critical step. To improve ape resilience, measures that protect nesting and feeding trees, as well as ape habitat in general, are also required. This can also include measures to prevent wildfires from spreading unintentionally, such as cutting fire breaks, as seen in Guinea’s Moyen-Bafing National Park. 

Moyen-Bafing is a newly designated national park in Northern Guinea. The region is home to nearly 20 per cent of the world’s remaining West African chimpanzee population, which is classified as critically endangered.

The Moyen-Bafing Chimpanzee Project, which began in 2022, is dedicated to understanding this unique population’s life history, behaviour, cognition and ecology, as well as promoting chimpanzee conservation throughout Africa.

Interventions that support farmers in years of crop failure or supplementary income sources can contribute to avoiding deforestation. In addition to supporting adaptation to climate change impacts, the creation of corridors and new protected areas is needed to avoid the isolation of ape populations.

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