Climate change is significantly affecting Africa's well-known Serengeti and Maasai Mara
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.
Every year, millions of animals move across the land in search of fresh grass and water, creating an incredible spectacle known as the Great Migration. This migration sustains hundreds of predators and scavengers like vultures. The wildlife is also important for local governments and communities that rely on funds from tourism and conservation efforts.
All this activity - the well-being of wildlife, the water they drink and the vegetation they feed on - depends on weather patterns. Extreme weather phenomena, therefore, can wreak havoc on the workings of the ecosystem.
I'm part of a team from 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. Our new study has found that it has been 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 4.8°C to 5.8°C.
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.
Key findings
We have 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 - an overall rise of 5.3°C. The minimum temperature increased from 7.9°C in May 1960, reaching 13.2°C in 2024.
Rainfall in both the Maasai Mara and Serengeti increased over time. Severe droughts are becoming more frequent and intense. And though extreme floods are relatively rare, they're also increasing in frequency and intensity over time.
What's driving these changes
By analysing patterns in rainfall and temperature alongside global oceanic and atmospheric climate systems, we connect the weather changes in the Mara-Serengeti ecosystem to climate change. The global climate systems are changing due to global warming.
Specifically, we examined the Southern Oscillation Index and the Indian Ocean Dipole (IOD) between 1913 and 2024. These are the most significant oceanic and atmospheric patterns affecting climate in east Africa.
The Southern Oscillation 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 - like El Niño (warm phase of the oscillation) or La Niña (cold phase) - which can affect weather patterns around the world. El Niño is linked to more rainfall in east Africa and La Niña to droughts.
The Indian Ocean Dipole is a climate pattern which is like a seesaw for the ocean temperatures in the Indian Ocean. Sometimes, one side of the ocean near Africa gets warmer, while the side near Indonesia gets cooler. Other times, it flips, with Indonesia being warmer and Africa cooler. This changing pattern affects the weather, causing more rain when the ocean near east Africa is warmer and droughts when the ocean is cooler.
Our study of the Southern Oscillation Index found that around 1970 the shifts in oceanic and atmospheric conditions that cause El Niño and La Niña were becoming more extreme. As a result, these events - and the droughts and floods they bring - are happening more often and with greater intensity.
Meanwhile, between 1913 and 2024, the Indian Ocean Dipole has slowly increased due to steady ocean warming. And there are two repeating cycles that happen every 4.1 and 5.4 years. These cycles change in strength and timing, but they keep coming back regularly. The steady strengthening of the dipole is a sign of global warming and altered atmospheric circulation. The increased frequency and intensity of dipole events, when there are warmer sea surface temperatures in the western Indian Ocean, are linked to more frequent and severe floods and droughts in the Mara-Serengeti ecosystem.
Implications of weather changes
The droughts, floods and temperature rise are affecting wildlife populations and biodiversity in the ecosystem.
We've seen this through field observations in annual reports by Kenya's Game Department and its successor, the Wildlife Conservation and Management Department, and from local district documents in the Kenya National Archives and there are also more contemporary observations.
We analysed this observational data to identify trends and patterns in wildlife populations over time, and the timing, scale and location of changes. We then linked these to changes in the weather and specific anomalies, such as droughts.
We also systematically ruled out other potential causes, such as disease outbreaks, habitat destruction, pollution or overexploitation, such as through poaching.
