Wildebeest are funny aminals. Even their name is wierd in English, though the etymology is straightfoward in Afrikaans (“wild cattle”). There are almost twice as many wildebeest in Serengeti as there are people in Austin. If you’re stuck on Mopac or the interstate at rush hour, you know that’s a lot of wildebeest. Wildebeest are migratory. They love short green grass so they follow it in a giant 2,800 km circuit every year. In February and March they have about half a million babies in the flat endless plains in south-eastern Serengeti. It rains from March to May here so they are assured an abundance of short green grass. The herds graze here till the rains end in May when they start moving in large numbers to the area near the Grumeti river in north west Serengeti. By July and August they start moving further north and cross the Mara river into northern Serengeti and across the Kenyan border into the adjoining Maasai Mara National Park. They stay here through the dry season and then with the short November rains they start moving south east back to the short grass plains, arriving by December. Then the cycle starts all over again. By migrating and following the food, the wildebeets swell to larger numbers than the ecosystem would have been able to support if they had been non-migratory. Though they probably don’t know that.
The herd population is fairly stable. That means there are a lot of dead wildebeest every year. They die from thirst, starvation, exhaustion, and predation by hyenas, lions, crocodiles, and other beasts of prey. About half a million gazelles and a quarter million zebras travel portions of the migration route with the wildebeest. The zebras particularly can been seen moving alongside the wildebeest. Incidentally, the zebra eat long grass. So they don’t compete for the same food as the wildebeest. Zebras a better at sensing prey animals, and wildebeest have learned to be very skittish, reacting quickly to a zebra who has detected a lion. In fact, wildebeest react to the safari 4x4s much more skittishly than any other animal we saw. All the animals are familiar with the 4x4s since birth. Beside wildebeests, other animals do not to fear the 4x4s. Most of them completely ignore you even if you are only a few feet from them as long as you are inside the ubiquitous 4x4s. But not the wildebeest. They buck and jump every which way and then they gallop away till then get turned around and realize that they are headed straight back at you and then chaotically gallop away again, in the process scattering a few dozen other wildebeest into panic.
As we drew closer to the Mara river we noticed huge herds of wildebeest. In the early morning or evening hours they move in long almost single file. Occasionally they gallop to catch up with the ones in front of them, but just as randomly they stop, turn around completely, and sometimes stampede in the opposite direction. In the heat of the afternoon they collect in tens or twenties under the scant shade of whatever trees there might be, motionless like statues. But the emergent trend through all this was a movement in the northen direction towards the Mara river, genetically driven to cross the river and head to the short green grass of Maasai Mara at this time of the year.
The first river crossing that we saw was pretty dramatic. They all are. Including dry washes and smaller creeks, we witnessed at least 6 crossings in three days. A herd had collected on a bluff overlooking the river. There was a wooded area in the middle. The way down to the river was via a steeply inclined path. The rest of the bluff was too tall to climb down. We were positioned on the other side of the river, back from the edge and hidden from view. When we got there, we joined about 20 safari 4x4s. But they must have been waiting for a long time because they slowly drove away till we were the only ones left. Meanwhile, the wildebeest milled around but made no move. Once a while one or two would walk purposefully towards the steep path down, but they always changed their mind and wandered away. Joshua told us that one animal needed to take the first step. It isn’t a leader. Wildebeest don’t have leaders. Just someone to trigger something in the brains of a dozen wildebeest around it, and the rest follow in a classic example of a herd or mob.