The East African landscape encompassing Kenya and Tanzania is renowned for its diverse wildlife and indigenous tribes. Over millennia, tectonic shifts, geomorphological processes, and climatic influences have wrought a unique mosaic of landscapes; rift valleys, freshwater and alkaline lakes, boggy swamps, volcanic mountains, craters, hotwater geysers, and savannahs. A long evolutionary history forged by these deep-time processes, as well as the remarkable interaction of the Masai tribes and the wildlife — where each depends on the other for its survival — has resulted in the region's rich biodiversity.
Here's a look at some of Kenya's geographical and geological formations which serve as a backdrop to its spectacular biodiversity.
EAST AFRICAN RIFT SYSTEM
The East African Rift (EAR) or East African Rift System (EARS) runs from Ethiopia in the north to Malawi in the south. It represents an area where the Earth's crust is pulling apart or rifting. EAR defines where the African Plate splits into two smaller plates called the Somali Plate and the Nubian Plate, in a slow-moving process that began during the Miocene period, around 22–25 million years ago. Both magmatism (the positioning of magma within and at the surface of the Earth), and tectonic plates (the movement of lithospheric shards) resulted in this unique rifting.
An aside: in India, two of our major rivers, Narmada and Tapi, flow through ancient rift valleys. If you were to trace their paths on Google Earth/Maps, you'd notice how these rivers meander less often than other rivers in India — that is because they follow pre-defined paths through hard, resistant rock.
Enclosed by escarpments on the east and west, the rift valley's floor is punctuated by both active and dormant volcanoes, some well-known examples include Mount Kilimanjaro, Mount Kenya, and Mount Longonot. As the escarpments eroded, they filled the valley with fine sediments, which have been great for preserving old bones and impressions.
1. FOSSIL FINDS
The Rift Valley in East Africa is like a treasure trove of ancient fossils, giving scientists a chance to study how humans evolved. Researchers have found the remains of several ancestors of modern humans, including the famous 'Lucy', a partial skeleton of an Australopithecus woman who lived over 3 million years ago. In 2008, Richard and Mary Leakey found the remains of two more ancient ape relatives: Chororapithecus abyssinicus, and Nakalipithecus nakayamai, both 10 million years old.
A cast of the remains of the Australopithecus afarensis, nicknamed Lucy after The Beatles' song, Lucy in the sky with diamonds, that the scientists were listening to when they discovered her. The cast lies in the Museum of Natural History, Paris. (Image credit: 120, CC BY-SA 3.0 via Wikimedia Commons).
2. RIFT VALLEY LAKES:
The volcanism in the region has created a landscape dotted with several lakes; Lake Malawi and Lake Tanganyika are notable examples. In Kenya, eight lakes lie within the rift valley; three freshwater lakes, and five soda lakes, each with its unique biodiversity. I had the chance to visit these two lakes to the northwest of Nairobi:
The ominous-looking surface of Lake Naivasha shortly after a downpour, with a flock of great cormorants making the most of the skeletal, submerged perches, while a group of fisherfolk tend to their nets in the background. (Image credit: Devayani Khare).
a. Lake Naivasha
A freshwater lake that marks the highest elevation of the Kenyan Rift Valley at 1,884 metres (6,181 ft), Naivasha is derived from a Masai word meaning 'that which heaves,' which can be interpreted to denote a surface that ripples under windy or stormy conditions. That is exactly how Naivasha was the day I visited — the leaden, overcast skies were reflected on its dimpled surface. Stark, skeletal acacia lined the lake's edge, the monsoon surge had taken a toll on these hardy trees. As we hopped into the boat, a sudden downpour obliterated the horizon. We were heading towards Crescent Island, a half-moon-shaped island close to the eastern bank, connected to the mainland by an occasional land bridge during the dry season. As we neared the island, the rain eased up, and we could see private residences and fancy resorts along the banks.
The story goes that in 1985, the 'Out of Africa' film was shot on Crescent Island, and animals like zebras, giraffes, gazelles, among others, were brought in from Masai Mara. Sadly, the film crew did not transport the animals back after the shoot, and they've thrived on the island, sheltered from predators. Occasionally, local authorities send some creatures back to the Mara or bring some in to maintain genetic diversity, but it has been turned into a tame, tragic tourist trap! The (hungry, hungry) hippos have claimed every inch of the lake's edge for their own, and there are often human-wildlife conflicts when fisherfolk get too close to hippo families.
The freshwater lake is also home to over 400 species of birds (with an introduced species, Fischer's lovebird), which made the trip worthwhile. We were lucky to see the African fish-eagle, the Giant Kingfisher, and the Green Woodhoopoe, as well as the usual suspects, egrets, lapwings, and cormorants.
White rhinos vie for muddy appeal with cape buffalos, along the shores of a flamingo and pelican fringed Lake Nakuru. (Image credit: Devayani Khare).
b. Lake Nakuru
Despite being located on the fringe of Nairobi, with the occasional view of buildings, Nakuru was wildly different from Naivasha. Nakuru, in the Masai language, translates to 'dust or dusty Place', thankfully, we saw it during peak monsoon when the lake was at its fullest and the undergrowth was thick and lush. Lake Nakuru is safeguarded under the Ramsar Convention, focused on the conservation of wetlands.
Lake Nakuru is a soda lake, surrounded by scraggly woods and thick undergrowth, and the national park makes up in species diversity what it lacks in size. If the sheer number of both lesser and greater flamingoes is anything to judge by, the lake's alkalinity must support teeming colonies of algae — after all, that's what the birds rely on for their pretty pink colour! Numerous waterbirds clamour for attention, both near the lake's edge and in the lily-ringed ponds, while forest birds flit through the thickets, totalling 400 resident species.
Beyond the birdlife, Lake Nakuru is also home to lesser-seen wildlife: the Rothschild's giraffe, and the black and white rhinos. We were also lucky to see two male lions, in full-maned regalia step out from the undergrowth and nonchalantly walk past us.
Flocks of flamingoes filter feeding along Lake Nakuru's shallows, they nest here in huge numbers every year. (Image credit: Devayani Khare).
3. VOLCANIC VESTIGES
Imagine a landscape of deep gorges singed by sulphur fumes, extinct volcanoes hewn away by time, leaving behind jagged, toothy spires, hotwater geysers that hiss and steam through fissures in rocks — these are some of the telltale signs of ancient volcano-forged landscapes.
A herd of Plains Zebras graze contentedly under the volcanic crags at Hell's Gate. (Image credit: Devayani Khare)
a. Hell's Gate
Defined by extinct, eroded volcanoes, with the occasional volcanic plug, a river-carved gorge, rugged crags, and obsidian caves — the stark features of Hell's Gate could well seem like the underworld (or paradise, if you're a geologist). The name was inspired by the narrow cleft or gorge in craggy cliffs, from where a tributary flowed into a prehistoric lake. The gorge, Ol Njorowa, was the inspiration for the iconic scene in the film Lion King, where a stampede of wildebeest tramples King Musafa, leaving a traumatised Simba behind. Though wildebeests aren't often seen in colossal herds here, impromptu downpours cause torrents of flash floods to cascade through the ravine. The sandy, less-absorbent riverbed abets this tempestuous flow.
Hell's Gate National Park is fenced off from other habitats, and creatures like zebras, giraffes, warthogs, and baboons roam more freely here, without predators (yet it doesn't seem as tame an experience, as Crescent Island). You can walk or cycle through the park, and even try rock climbing over the sheer, volcanic plugs like Fischer's Tower. I rented a cycle for the first 8 kilometres through the park; I could find the perfect pace for wildlife and geology photography, rock collecting (the path was strewn with beautiful, black-glass-like obsidian, and hard, sponge-looking pumice), and birdwatching. In the distance, an occasional steam spire would rise, as if someone in the valley was sending smoke signals — these were the telltale signs of the hotwater geysers, which have been tapped for geothermal energy. The Ol Jorowa gorge was scoured and sandy in places, damp with a sulphuric smell in others, with slimy, dark-green algal mats.
Later, I explored a three-kilometre trail on foot, with a local Masai guide. He told us about the medicinal herbs used by the locals, how the film Tomb Raider was shot here, and pointed out the formations that had inspired the Lion King animators — notably, Pride Rock, which turned out to be a lot smaller, yet with a giddying view into the valley below.
4. BIODIVERSITY CORRIDORS
The Mara river marks the boundary between Kenya and Tanzania, and this stretch is where the annual wildebeest migration takes place. The photo was captured from Kenya's banks, overlooking Tanzania on the other side. (Image credits: Devayani Khare).
Stretching across Kenya and Tanzania is a mosaic of habitats; open savannah, riverine forests, swamps, Acacia woodlands, non-deciduous thickets, and boulder-strewn escarpments. This mosaic hosts millions of herbivores, and the predators that depend on them, as well as numerous birds, reptiles, amphibians, and insects, that form the circle of life! Perennial rivers like the Mara and Talek wend their way through this landscape and a three-month wet season regulates the vegetation and creates ephemeral watering holes. This seasonality drives herbivores like the wildebeest and zebras to migrate in search of greener pastures, and they leap across a seething river from one country into the other. The Serengeti in Tanzania, and the Masai Mara in Kenya, are part of the same biodiversity corridor and are defined by similar mosaicked habitats.
a. Masai Mara
Though the Masai Mara falls within the East African Rift System, it is difficult to imagine this wide, open landscape of 1,500 sq. kilometres nestled within a fault line. Yet the rift stretches over 5,600km (3,500 miles) and works its way from north to south, from Ethiopia's Red Sea through Kenya, Tanzania, Malawi and into Mozambique. The eroded escarpments are just hazy features in the distance, and the breathtaking scale of the Masai Mara valley, teeming with herbivores is a sight to behold.
The Mara ecosystem hosts a diverse array of large herbivores and smaller species. It boasts the world's largest variety of savannah species, including gazelle, buffalo, impala, topi, hartebeest, giraffe, eland, hippo, warthog, elephant and numerous species of antelope. The region also supports substantial populations of lions, spotted hyenas, cheetahs, and endangered species like the black rhinoceros and African hunting dogs. With over 500 species of birds, of which more than 50 are raptors, Masai Mara is a wildlife paradise. Trying to decipher the landscape and its geographical mysteries when on exciting game drives, was a lost and futile cause. I had to content myself with reading up before and after the trip.
The incredible mosaic of habitats across the Mara — short grasslands on shallow, fertile soils, Acacia-dominated woodlands with tall grasses, hardy, evergreen trees that lend it a 'spotted' look (the word Mara, means spotted, like the coat of a cheetah) and shrublands, scraggly undergrowth along the river's edge — play a crucial role in supporting large numbers of herbivores. Rainfall patterns and other climatic factors, cycles of seasonal grass fires, the constant grazing of herbivores, and the fluctuations of river levels, have further shaped the landscape, and the biodiversity has evolved to cope with this variability. Lastly, and most importantly, the Masai tribe's cultural practices, conservation initiatives, and the principles of sustainable coexistence with wildlife have helped preserve the Mara landscape.
Hopefully, the faint rainbow holds promise of more trips across the Masai Mara in the near future. (Image credits: Devayani Khare).