The Migration That Wasn’t

October 29, 2019
Africa Blog #4

Our photo safari was timed to coincide with the annual Great Migration, now named one of the Seven Wonders of the New World. Wildebeest in the millions,  accompanied by hundreds of thousands of zebras and assorted gazelles, migrate in a circular rotation 500 miles south in the spring from the Serengeti in Tanzania to the Maasai Mara in Kenya, returning again in the October-November time frame, arriving in time for calving season early in the year. Wildebeest are strange-looking creatures. We saw them every day, grazing the grasslands by the thousands, putting us in mind of herds of bison in the bygone history of the American West, a similarity enhanced by their dark color, shaggy mane, and humped shoulders. But they have a lighter frame than the buffalo, and I was surprised to learn they are actually a variety of gazelle. 

The migration is driven by rainfall which causes new grass to sprout up seemingly overnight, forage these grazing animals need for their survival. The great predators follow on the heels of this migration, picking off the young, the old, the weak, the lame and sick that trail behind the mass herds. It is estimated some 250,000 wildebeest die each year on the migration from predation, as well as hunger, thirst, and exhaustion. The wildebeest have developed an interesting survival technique as a species – almost all the young are born within a short two to three-week span in the spring. In all, some 500,000 wildebeest calves are born each season. The short calving season creates an oversupply of vulnerable young calves on the predator menu. As a result, more calves will survive, due to sheer numbers, than if the calving season stretched out over a longer time span.

But despite our timing and the multitude of wildlife sightings we were privileged to see, the one thing we missed out on was the Migration. It’s a pretty dramatic event, as thousands and thousands of wildebeest start organizing into lines and head en masse towards the Mara River, which they must cross in order to head north into Tanzania. Even though the wildebeest are the main force of the migration, the zebras that migrate with them are braver and tend to be the first to test the waters, leading the way. Depending on how wet or dry the year is, the Mara River can be deep with swift currents, forcing the animals to plunge down the riverbanks and swim, or if shallow to splash their way across. Either way, huge Nile Crocodiles are lurking in the water, waiting for an opportunity to grab their prey. When the river is deep, the crocs will pull their victims under and drown them. In shallow water they grab hold and an epic (and gory) struggle ensues that can go on for an hour or more. Obviously, the photo opportunities can be dramatic. But for whatever reason, the wildebeest just weren’t ready to commit during our visit. We witnessed one minor crossing when a herd organized and headed, not to the Mara River, but to the benign Sand River where all they had to do was wade through gently flowing shallow water with nary a crocodile lying in wait. 

But we did see the crocodiles, and they are massive. Specimens have been recorded exceeding 20 feet in length and weighing up to 2400 pounds. They are aggressive and will eat any creature that gets within range using an ambush-style attack, and are responsible for hundreds of human deaths each year. We actually took a lunch break one afternoon on the banks of the Mara, where the crocs were stretched out on the sandy shore or swimming rapidly downstream, accelerating in the strong current. Needless to say, we kept a respectful distance from the river’s edge while we ate.