The Serengeti ecosystem spans approximately 30,000 square kilometers in northern Tanzania, extending into Kenya’s Maasai Mara National Reserve. This vast area of savanna, woodlands, and riverine forests is a UNESCO World Heritage Site. The name “Serengeti” is derived from a Maasai word meaning “endless plains,” a description that captures the scale of this biologically rich landscape. The region’s diverse habitats support an unparalleled concentration of wildlife.
The Great Migration Participants
The Serengeti’s most defining event is the annual Great Migration, involving over two million animals moving in a continuous cycle driven by grazing and water availability. Blue wildebeest (Connochaetes taurinus) constitute the majority, with an estimated 1.5 million individuals. These ungulates are the primary drivers, constantly searching for the highly nutritious short grasses that emerge after seasonal rains. As ruminants, their digestive system allows them to extract maximum nutrients from the leafy parts of the grass.
Plains zebras (Equus quagga) travel in close association with the wildebeest, numbering approximately 200,000. Zebras, as non-ruminants, consume the taller, less nutritious parts of the grass first, preparing the grazing land for the wildebeest that follow. This sequential grazing reduces competition, allowing both species to utilize resources efficiently. The combined presence of these large herds provides safety in numbers, diluting the risk of predation.
Thomson’s and Grant’s gazelles also join the processions, with combined numbers estimated at around 500,000 animals. These smaller, agile herbivores graze on the shortest grasses and forbs, often lingering on the plains after the main herds have moved on. They utilize the final stages of the available forage. The entire movement is a response to localized rainfall and nutrient patterns across the ecosystem.
Iconic Predators and Scavengers
The massive herbivore populations support one of the highest concentrations of large carnivores globally, with the African lion (Panthera leo) being the most prominent. Lions live in social groups called prides, a unique trait among cat species, enabling them to cooperatively hunt large prey such as Cape buffalo and wildebeest. Lionesses perform most of the hunting, using coordinated ambush tactics during the cooler hours of dawn, dusk, or at night. The Serengeti ecosystem is home to an estimated 3,000 to 4,000 lions.
Cheetahs (Acinonyx jubatus) utilize their speed to chase down swift prey like gazelles on the open plains. These predators prefer to hunt during the day to avoid direct competition with more powerful nocturnal carnivores. Cheetahs rely on a rapid sprint for a kill, contrasting with the endurance-based hunting of other predators. Leopards (Panthera pardus) are the most elusive of the big cats, preferring solitary, stealthy hunting in the denser woodlands and riverine habitats.
Leopards frequently drag their kills into trees to secure them from scavengers and other predators. Spotted hyenas (Crocuta crocuta) are both effective predators and efficient scavengers, living in complex, female-dominated clans. Hyenas can pursue prey over long distances and consume nearly every part of a carcass, including bone. The Serengeti also supports a monitored population of endangered African wild dogs (Lycaon pictus), known for their highly cooperative pack hunting methods.
Major Herbivores (Beyond the Migration)
Beyond the migratory herds, numerous resident large herbivores maintain the structure of the Serengeti habitats. African bush elephants (Loxodonta africana) are major ecosystem engineers, whose feeding habits significantly influence the boundary between woodland and grassland. Their population in the Serengeti-Mara ecosystem has been increasing, with recent counts exceeding 8,000 individuals. Elephants strip bark from trees and push over woody plants, which helps maintain the open nature of the savanna.
The Cape buffalo (Syncerus caffer) is a large, resident grazer, often found in herds near permanent water sources and areas of coarser grass. These powerful animals are known for their unpredictable temperament and form cohesive groups that aggressively defend against predators. Giraffes (Giraffa camelopardalis) are specialized browsers, feeding on leaves and buds high up in acacia and other trees inaccessible to most other herbivores. Their selective feeding patterns prevent the overgrowth of certain tree species.
Hippos (Hippopotamus amphibius) are confined to river systems, such as the Grumeti and Mara Rivers, spending their days submerged to protect their skin. They emerge at night to graze on short grasses near the banks, acting as nutrient transporters between the aquatic and terrestrial environments. The critically endangered black rhinoceros (Diceros bicornis) is also present, primarily within protected zones like the Moru Kopjes, requiring intensive conservation efforts.
Avian Diversity and Smaller Fauna
The Serengeti harbors a spectacular avian diversity, with more than 500 bird species recorded across its varied landscapes. This includes large, terrestrial birds like the common ostrich (Struthio camelus), the kori bustard, which is the heaviest flying bird native to Africa, and the distinctive secretary bird. The ecosystem also hosts several endemic “Serengeti specials,” bird species found nowhere else on earth. Raptors like the African fish eagle and various vultures also patrol the skies, with vultures acting as the ecosystem’s primary, highly efficient scavengers.
Smaller fauna, while less visible, play fundamental roles in maintaining the health of the plains. Crocodiles (Crocodylus niloticus) are prominent in the major rivers, particularly during the migration river crossings where they capitalize on the massive concentration of ungulates. Insects, such as the numerous species of dung beetles, are important for nutrient recycling. Over 100 species of dung beetles have been identified, which quickly bury and process the tons of animal waste dropped daily, preventing the spread of disease and enriching the soil.
Other smaller mammals include primates like baboons and vervet monkeys, which are often sighted in the woodlands and kopjes. Various mongoose species and smaller rodents also inhabit the grasslands. Even grasshoppers, with over 60 identified species, can consume a significant amount of vegetation at certain times of the year, demonstrating that the Serengeti’s wildlife extends far beyond its famous large mammals.