"Who are you and on whose authority are you here?" His voice was loud, authoritative and intimidating. He wielded a rungu (baton), , the kind you might use to steady yourself when walking, but which can also be quickly converted into a weapon. He was flanked by three other men, armed and moving quickly towards us.
"Who sent you here?" he barked again. In an instant we were surrounded by six more men, coming from different directions, some shouting at us. They blended perfectly into the landscape, a major reason why we didn't see them approaching until we were surrounded.
We identified ourselves as journalists following a story, but they refused to back down.
"Unless you have permission from the Ministry of Defence, you must leave. Now!" They were Kenya Defence Forces, and we had apparently trespassed on their land, no matter that there was no fence or signs. We left as instructed, and for a moment we worried that our story had been ruined. We were about to record interviews when the soldiers showed up and threatened to delete our footage. In the end, we decided to change the location of the interviews. We'd come in search of wildebeest.
For decades, the thundering hooves of millions of wildebeest have echoed across the East African savannah, following the rhythm of the seasons in a breathtaking spectacle known as the Great Migration. But this annual pilgrimage, considered one of nature's greatest wonders, is facing an unprecedented threat: human development. Highways and fences, built in the name of progress, have severed ancient trails and upset the delicate balance of ecosystems.
"I was born in this area of Kitengela, and at that time we had wildebeest everywhere, migrating from Amboseli to Nairobi National Park. That was in the early 1970s. Even into the 1980s, there were lots of wildebeest here. At that time there was very little human activity, very little development. The problems we have now with building and subdividing land, we did not have back then," says Jeremiah Karoi. He's a resident of Kitengela and a wildlife enthusiast.
As Kenya's population grew and its cities expanded, the wilderness shrank. The Maasai Mara, once a haven for wildlife, has been surrounded by fences and concrete. Highways cut through ancient migratory routes, disrupting the flow of life. The grasslands, once vast and uninterrupted, gave way to fields of crops and settlements. As a result, wildlife migrations that existed in the country no longer exist.
"Today we have towns that didn't exist before, in areas where animals used to migrate. These towns, like Kitengela, exist in what used to be a wildlife migration corridor. So when land subdivision started and development started, wildlife migration was affected," he said.
"Kenya used to have a lot of wildlife migration, such as the zebra and the Thompson gazelle. They used to migrate between Lake Nakuru and Elementaita to the Baringo and Solai area," said Dr Joseph Ogutu, a senior statistician and researcher at the University of Hohenheim in Germany. "This migration was actually the most spectacular in Africa, but because of cultivation over the years, it collapsed in 1920," he added. When the military officers who had surrounded us inquired about our business in the area, they seemed very disturbed by Dr Ogutu's presence. They wanted to know why we had brought a researcher with us.
"In fact, the only migration left is the one known as the great migration, the Mara-Serengeti migration. And if the Mara were completely separated from the Serengeti, there would be no migration. As we speak, the number of wildebeest and zebra crossing from the Serengeti into the Mara has declined. In the early years, when regular migration monitoring began in 1977, more than a million wildebeest entered Kenya each year. By the 1990s, that number had fallen to less than 500,000, and today it's less than 250,000. So not only have the numbers of animals coming from the Serengeti into the Mara dropped significantly, but the few that do stay are doing so for much shorter periods of time," Dr Ogutu explains.
"Our calculations show that by 2018, the animals were spending 35 fewer days in the Mara. In total, they usually spend three months. So if you subtract one month, that leaves only two months; if this continues, they will spend less and less time. You can imagine the impact on tourism because tourism in the Mara is mainly driven by migration.
"The Maasai traditionally live in the wild and with the wildlife: Daniel Katoo, a community elder in Kitengela, says. "But I agree that we have restricted the animals' freedom of movement through haphazard construction. Animals used to move from Nairobi to Serengeti in this area, and some went to Amboseli," he said. "Animals have no borders. They used to move easily between countries until people created borders and fenced them off".
"You also have to consider that we have not increased the size of the national parks or reserves, yet the animal population is also growing," said Tony Osiora, a resident of Kajiado. "As the human population grows, so does the animal population. But the difference is that while humans can expand their territories, animals can't. So the human expansion squeezes the animals into a very limited space.
"I was part of a task force two years ago that looked at wildlife corridors that existed in the past and how they connected parks and reserves with animals. We travelled around the country documenting, particularly in Machakos and Kajiado counties, looking at migration routes. We learned that these routes no longer exist. Here in Kitengela and Athi River, the migratory route goes from Nairobi National Park, through Kitengela town, the Export Processing Zone, Namanga Road, Portland Cement and into the conservancies in Machakos County," said Karoi.
"Even in areas where roads are being built on prime wildlife habitat, there is no provision for overpasses or underpasses. Take the case of the Athi River to Namanga road; when this road was upgraded not too long ago, some wildebeest used to cross from Nairobi Park to the eastern side to the Athi-Kaputei plains. But soon after the road was upgraded, the animals could no longer cross and the migration collapsed," says Dr Ogutu.
Today, the only sounds you hear in the Athi-Kaputei area are crickets, occasionally interrupted by the sound of passing vehicles. If you were to travel back in time to the 1970s, this now empty grassland would be teeming with elephant, rhino and zebra. Today, the Athi-Kaputiei wildlife population has declined by 90.8 per cent from 30,000 wildebeest in the 1970s to 2,750 resident animals in 2021. Further down the road in Amboseli, the population has plummeted from from 16,300 animals in the 1970s to just 2,400 wildebeest by 2014, but will later increase to 9,162 by 2021.
The researchers say the biggest culprit is the lack of a land-use policy. Because the problem has been allowed to continue for so long, it will take a very long time to reverse the damage that has already been done.
"It's important to note that although Kenya's wildlife population has declined by 70% since the 1970s and continues to decline, only 8.2% of what's left is in national reserves of protected areas. The rest are lost among humans, cut off from their herds. So if we are to revive the migrations, we also need to provide places where they can spend the dry season - concentration areas like Nairobi National Park used to be. Then they need the wet season areas where they calve and the corridor that connects these two areas," said Dr Ogutu.
Efforts are underway to mitigate the impact of human development on wildlife migration, but progress is slow. Conservationists advocate the creation of wildlife corridors and the implementation of measures to reduce human-wildlife conflict along migration routes.
"Wildlife is God-given. Tourists pay a lot of money to come and see it. So it is our responsibility to ensure that the animals are protected, and that starts with restoring the migratory routes," said Karoi. "But we have to recognise that because of changing land use, much of the land that wildlife used to use is now in private hands. That's why our task force recommended that the government should repossess this land and compensate these private owners," said Karoi.
But the challenges are immense, requiring a delicate balance between the needs of a growing human population and the preservation of Kenya's natural heritage. As the fate of the wildebeest migration hangs in the balance, the world watches, hoping that mankind can find a way to coexist with the wild creatures that call Kenya home.
