“Our planet is changing. It’s indisputable that migrations are heavily informed by climate and by wildlife corridors and the landscapes that are available. Every migration that we filmed and many we didn’t film is informed and challenged by the air-space, land-space and water corridors that are available to these animals.”
The annual wildebeest migration in Tanzania and Kenya’s Serengeti ecosystem is under threat.
And for once the rapidly emerging climate emergency isn’t entirely to blame, though it doesn’t help.
Instead its human population growth, habitat destruction and the constant encroachment of ever-expanding human settlements, in the form of fences, farms, roads, railway lines, bridges and highways that are the primary cause.
Conservationists have made the case for wildlife corridors and, in some cases, highway overpasses, such as those that have provided a Bandaid solution in populated, urban areas in Southern California.
A recent study analyzed the movement of East Africa’s migratory wildebeest in five separate ecosystems, incorporating data from aerial surveys collected over some 60 years (1957-2015) in Kenya and Tanzania. The study found that four of the five migrations have virtually collapsed.
The world famous Serengeti-Mara ecosystem covers some 40,000 km² (15,400 square miles) and straddles Kenya and Tanzania. Researchers determined that since 1977, the total number of wildebeest in the area has stayed at roughly 1.3 million animals — but — the number of wildebeest making the annual crossing from Serengeti National Park in Tanzania to the Maasai Mara National Reserve in Kenya has fallen some 73% during that time — 157,000 wildebeest in 2016, down from 588,000 in 1979.
Over that same period of time, the number of migrating wildebeest crashed 95% in Athi-Kaputiei, near the Kenyan capital Nairobi, from 27,000 wildebeest in 1977 to fewer than 3,000 in 2014.
Migrating wildebeest are down some 85% in the Greater Amboseli region, an area of roughly 7,700 km² (3,000 square miles) that, like the Serengeti-Mara ecosystem, straddles Kenya and Tanzania.
Migratory populations have fallen some 81% in Mara-Loita, in south-western Kenya, and 72% in the self-contained Tarangire-Manyara ecosystem, in northern Tanzania.
The threats vary from area to area — evidence, perhaps, that climate change is not entirely to blame.
Poorly planned agricultural expansion, poaching, illegal hunting for bushmeat, competition with livestock for grazing grounds, and unpredictable, ever-changing water points all come into play. Droughts are more prevalent, and unpredictable — that part is down to climate change.
The way land is used is changing, too, from pastoral herding to subsistence farming, with former grazing areas being turned into farmland.
This increases the likelihood of human-wildlife
conflict. Elephants for example raid villagers’ crops, instead of staying close the acacia tree cover and plains of protected areas like Amboseli National Park, and hungry lions roam outside park boundaries for the easier — and more plentiful — pickings of domestic livestock.
Kenya’s conservation policy focuses on protected areas, which is only natural, especially for a country that relies so heavily on tourism. The problem is that protected areas encompass just 8% of the country’s land surface, and contain 35% of the country’s total wildlife.
The other 65% ekes out a precarious existence on privately owned land, which wildebeest migrations cross at some point in their route.
Unlike Southern Africa, where privately owned game reserves outnumber national parks by a wide margin, there are relatively few privately owned game reserves in East Africa, and little incentive for private landowners to look after wildlife. Tourists tend to stick to a handful of well-known, heavily promoted areas, so other land uses — agriculture and livestock — have more appeal to the landowner trying to make a living off the land.
The study suggested a number of potential solutions to what will, if left unchecked, become an existential problem. “Saving the migrations means more regulation, securing more land, partnering with local communities and, ultimately, reducing human population growth,” the study authors noted,“regulation of livestock numbers, fences, settlements, farms and roads.
“Land must be restored, settlements cleared and cultivation on migration routes stopped, and key rivers (like the Mara River, which could be dammed) must be protected.
“Major roads that cut across migratory routes should include underpasses and/or overpasses for migrating wildlife. And robust law enforcement is needed to reduce the illegal hunting of animals for bushmeat.”
The consequences of not acting will be dire, Joseph Ogutu, University of Hohenheim statistician and one of the study’s lead authors, concluded. “Migrations of zebra and Thomsonʼs gazelle in Kenyaʼs Rift Valley and elephants in Kenya have already been lost. Wildebeest could go the same way.”
As mzee Jomo Kenyatta, founding president of the Republic of Kenya once said, “The natural resources of this country, its wildlife which offers such an attraction to visitors from over the world, the beautiful places in which these animals live, the mighty forests which guard the water catchment areas so vital to the survival of man and beast, are a priceless heritage for the future.”
Losing that would be a shame indeed.