Increasing erratic weather patterns are disrupting the delicate balance of the Mara-Serengeti, which relies on a predictable cycle of wet and dry seasons, scientists have warned.
The Mara-Serengeti ecosystem, one of the world’s most iconic wildlife habitats spanning Kenya and Tanzania, faces unprecedented challenges due to climate change, the study led by Joseph Ogutu of the University of Hohenheim, Isaiah Obara of Freie Universität Berlin, and Holly Dublin of Wasaa Conservation Centre, said.
The study warns that iconic migratory events, such as the Great Migration, are at risk as shifts in water availability and vegetation influence migratory routes and animal behavior.
The risks are compounded for endangered species, which already contend with threats from habitat loss and poaching. It further warns that the drying of the Mara-Serengeti ecosystem from climate change is threatening its unique biodiversity, with certain species struggling to adapt to the shifting conditions.
During prolonged droughts, water sources shrink, and grasses wither, making survival increasingly difficult for herbivores like wildebeests, zebras, and gazelles.
This, in turn, impacts predator species that depend on these herbivores for food, creating a ripple effect that threatens the entire food chain.
“Since 1960, the region has seen a staggering 5.3-degree Celsius increase in minimum temperatures, a change largely linked to the warming of the Indian Ocean.
This sharp rise in temperature has had severe implications for the ecosystem, accelerating habitat desiccation and reducing the availability of water and vegetation—essential resources for the survival of wildlife,” said the team in a paper published this month in the open-access journal PLOS Climate.
The interactions between global climate change and ocean oscillations – fluctuating cycles in wind and ocean temperatures – are impacting weather patterns in the Greater Mara-Serengeti ecosystem in Kenya and Tanzania, according to the study findings.
In the new study, researchers used various models to analyze long-term patterns, cycles, and seasonality in rainfall, temperature, and vegetation in the Greater Mara-Serengeti ecosystem, as well as the effects of ENSO and the Indian Niño.
Their findings show recurrent severe droughts and unpredictable wet conditions, alongside a significant temperature increase of 4.8 to 5.8 degrees Celsius over six decades.
While wet and dry season rainfall amounts have varied cyclically, the average yearly rainfall has remained stable, continuing in regular seasonal patterns.
However, from 2010 to 2020, rainfall exceeded average levels in both seasons, likely driven by global warming and the Indian Niño.
The impacts of global climate change are now widely recognized, but the regional impacts – especially in the Southern Hemisphere – are less well understood.
In the Southern Hemisphere and particularly in East Africa, climate change is primarily manifested through fluctuations in wind and sea surface temperatures that cause irregular cooling and warming periods, specifically, the global El Niño-Southern Oscillation (ENSO) in the Pacific Ocean and the regional Indian Niño in the Indian Ocean.
These phenomena influence rainfall and temperature, making their patterns and interactions crucial to understanding the regional impacts of climate change.
The researchers conclude that understanding regional climate trends and how they are influenced by large-scale oceanic and atmospheric oscillations is crucial for predicting future climate conditions and mitigating their impact on people and animals.
For example, droughts increase the risk of starvation for wildlife, shrink wetlands and intensify human-wildlife conflicts, while heavy rainfall can lead to habitat destruction.
The insights from this work can be used to develop strategies to reduce the impacts of climate change in the region and to inform environmental planning and conservation efforts.
