The Mara-Serengeti ecosystem, which includes Kenya’s Maasai Mara and Tanzania’s Serengeti National Park, is one of the most famous and wildlife-rich areas in Africa.
However, climate change is now having a significant impact on wildlife populations and biodiversity in the area, as well as tourism.
Every year, millions of animals move across the land in search of fresh grass and water, known as the Great Migration, which sustains hundreds of predators and scavengers, such as vultures.
The wildlife is also important for local governments and communities that rely on funds from tourism and conservation efforts.
In recent decades, however, extreme weather phenomena, brought about by climate change, have been wreaking havoc on the ecosystem.
A new study by the universities of Hohenheim and Groningen, Free University of Berlin, the IUCN, the Indian Institute of Management in Udaipur and the Kenya Meteorological Department, which has been studying weather patterns in the Mara-Serengeti ecosystem since 1913, has found that it is experiencing major changes.
“Over the past six decades, rainfall has been above average and there have also been recurrent severe droughts, erratic extremely wet conditions and a temperature rise of 4.8C to 5.8C,” wrote Joseph Ogutu, Senior Researcher and Statistician at the University of Hohenheim via the outlet The Conservation.
“These events are having a significant impact on wildlife populations and biodiversity in the area. Vegetation and water are gradually drying. Competition between wildlife, livestock and people for resources is increasing. Wildlife numbers are falling and there are changes in patterns of migration and breeding.”
The new study has found that the Mara-Serengeti is rapidly warming. The average monthly minimum temperatures – taken in Narok Town, bordering the Maasai Mara ecosystem – between 1960 and 2024 increased significantly, with an overall rise of 5.3C, according to Mr Ogutu. The minimum temperature increased from 7.9C in May 1960, reaching 13.2C in 2024.
“Rainfall both in the Maasai Mara and Serengeti increased over time. Severe droughts are becoming more frequent and intense,” he continued. “And though extreme floods are relatively rare, they’re also increasing in frequency and intensity over time.”
Through analysing patterns in rainfall and temperature as well as global oceanic and atmospheric climate systems, scientists have connected the weather changes in the ecosystem to climate change. The systems are changing due to global warming.
The scientists examined the Southern Oscillation Index and the Indian Ocean Dipole (IOD) between 1913 and 2024 – the most significant oceanic and atmospheric patterns affecting climate in East Africa.
The former index measures the difference in air pressure between two places – Tahiti in the South Pacific and Darwin in Australia. When the sea level pressure difference is big it signals changes, which can affect worldwide weather patterns. For example, El Nino is linked to more rainfall in East Africa, and La Nina to droughts.
The IOD is a climate pattern which acts like a “seesaw” for the ocean temperatures in the Indian Ocean, changing temperatures near Africa and Indonesia on the other side. This causes more rain when the ocean near East Africa is warmer, and vice versa.
The study of the Southern Oscillation Index revealed that around 1970 the shifts in oceanic and atmospheric conditions that cause El Nino and La Nina have become more extreme, with the droughts and floods they bring happening more frequently and with greater intensity. Meanwhile, between 1913 and 2024, the IOD has slowly increased due to steady ocean warming, with repeating cycles which change in strength and timing occurring every 4.1 to 5.4 years.
“The increased frequency and intensity of dipole events… are linked to more frequent and severe floods and droughts in the Mara-Serengeti ecosystem,” said Mr Ogutu.
Such weather changes are affecting wildlife populations and biodiversity in the ecosystem, including droughts killing wildlife through starvation, thirst and dehydration and an increase in human-wildlife conflict as wild animals raid crops, kill livestock and kill or injure people.
Additionally, droughts temporarily increase carcass availability, boosting predator numbers, but as prey numbers decline, predators also face starvation and their numbers decrease. They also suppress reproduction, reducing birth rates, milk availability and successful mating, which leads to unseasonal carving and high mortality among young animals.
On the other end of the scale, while heavy rainfall replenishes water resources and promotes plant growth, it also causes wildlife drownings and the destruction of habitats. The rainfall also brings sudden drops in temperatures which can be fatal to weakened animals. Finally, droughts also bring diseases, such as anthrax and rinderpest outbreaks and pathogens such as parasitic lungworms.
