Kenya’s location and range of altitude and its climate, dominated by the Indian Ocean’s monsoon winds, have given rise to a diverse range of ecosystems. From lowland rainforest to savanna grassland, high-altitude moorland to desert, and coral reef to mangrove swamp, these zones provide equally varied habitats for its extraordinary fauna and flora. With few large rivers, Kenya’s riverine habitats are restricted, but those that exist – notably the Tana and the Athi-Galana-Sabaki – are extremely attractive to wildlife. The vast, relatively shallow expanse of Lake Victoria, fed mainly by rainwater rather than rivers, is low in nutrients, but ideal for papyrus beds and marshes, harbouring birds found nowhere elsewhere in Kenya.
Lowland forest and woodlands
West of the Rift Valley, the 240 square kilometres of the Kakamega Forest, and a few adjacent outliers, are examples of the “Guineo-Congolan” equatorial forest, usually found only in central Africa and home to many animal and plant species encountered nowhere else in Kenya. Beyond Kakamega, Kenya’s once widespread forests are now limited largely to the highlands, notably Mount Kenya and the Aberdare range, and to a much smaller extent the coast, where patches of old forest often correspond to the sacred groves or cultural villages of the Mijikenda, known as kaya.
The wooded savanna of grassland with scattered trees – East Africa’s archetypal landscape – covers large areas of Kenya between about 1000m and 1800m. The main grasslands are in the Lake Victoria basin, which includes the Maasai Mara, and east and southeast of Mount Kenya, where the savanna is protected by the national parks of Meru and Amboseli and the better watered areas of Tsavo East and Tsavo West. Dry-season fires are quite common – whether natural or deliberately set to encourage new pasture with the first rain – and many of the often broad-leaved and deciduous trees are protected by their cork-like bark. The savanna of the Great Rift Valley is dotted with bird-rich lakes – ranging from freshwater Naivasha and Baringo to intensely saline Magadi and Bogoria – which act as a magnet for wintering migrants from Europe and northern Asia.
Starting just 30km inland from the Indian Ocean, a vast region known as the nyika – “wilderness” – stretches west across the drier areas of Tsavo East and West to the edge of the central highlands. Nyika is characterized by an impenetrably thick growth of stunted, thorny trees with scaly bark, such as acacias and euphorbias. Grey for most of the year, they sprout into a brilliant palette of greens during the rainy season. Where the land is lower than around 600m and there’s unreliable rainfall and strong winds, the vegetation is sparse and scrubby, with tufts of grass, scattered bushes and only occasional trees, mainly baobab and acacia. In these semi-arid areas, where much of the ground is bare and soil is easily removed by the wind, long droughts are common. Kenya’s true desert habitats are drier still, with very limited plant life and only dwarf trees and bushes. Large areas of northern Kenya consist of bare, stony or volcanic desert with thin, patchy grasses and the odd bush along seasonal watercourses.