The greatest show on earth
The greatest show on earth
Text: GG van Rooyen
Photography: André van Vuuren
In 1958, renowned Polish conservationist Bernhard Grzimek and his son, Michael, conducted the first scientific study of the annual east African wildebeest migration. Making use of a German Dornier Do 27 single-engine aircraft (the first study to use an aircraft to track animal movements in Africa), the duo followed the herds of wildebeest as they trekked through the Serengeti National Park.
For the elder Grzimek it was an awe-inspiring scene that defied comprehension. In fact, he found it difficult to believe that the African plains could sustain such a large number of herbivores.
In Serengeti shall not die, a book written after the trip, Grzimek asked: “Would the animals be able to go on living here? Were there enough plains, mountains, river valleys and bush areas to maintain the last giant herds still in existence? We had already noticed that large herds of wildebeest roamed outside the present boundaries of the park, and it was intended to change the borders to lessen its area.
“Nobody can follow these huge regiments of wildebeest and enormous armies of gazelles, and no-one knows where the hundreds of thousands of hooves will march. We were filled with fear and foreboding.”
Despite their limited knowledge about the wildebeests’ migration movements and their basic equipment, the Grzimeks set about establishing the number of wildebeest in the Serengeti by dividing the area into blocks and counting the animals as they flew over them in their little Dornier. By the end of their study, they had arrived at a number that Bernhard Grzimek viewed as astronomical: 99 481.
Could this be correct? Surely the Grzimeks must have been off by a very substantial number? After all, around 1,3 million wildebeest can now be found in the area. Well, their number might have been slightly off, but it was in the right region, because the wildebeest population was at an all-time low.
Rinderpest had entered Africa through Ethiopia in the early 1900s and decimated the wildlife population. So when the Grzimeks studied the wildebeest herds in the 1950s, it is very likely that the overall population numbered only in the tens of thousands.
By the end of that decade, however, diligent vaccination of livestock brought an end to the spread of rinderpest and the wildebeest population blossomed once again. Within a few years there were well over one million wildebeest in the region.
Now, considering Bernhard Grzimek’s concerns regarding sustainability when the population was, in fact, at an all-time low, how can this enormous number of animals be sustained today? The fact is, no one really knows. Africa’s ability to sustain massive herds of animals continues to astound conservationists.
To be sure, we have a greater understanding of the migration than ever before, but a number of questions remain. For instance, why has the wildebeest population increased to 1,3 million since the 1950s while the zebra population remained stable throughout the 1900s? Zebras were not affected by rinderpest and can still be found in the same numbers as 50 years ago, which is surprising if one considers the massive increase in wildebeest numbers. For some reason, an increase in both predators and food availability did not influence their population.
How the wildebeest herds navigate during their migration is also a mystery. Although the general yearly route remains the same, the herds alter their movements depending on rainfall and have illustrated an ability to detect rain from 50km away. How exactly they do this, however, remains uncertain.