Photograph of the week: Wildebeest migration river crossing in the Masai Mara

Every year, between May and December, over 1.5 million wildebeest, 300,000 zebra and a host of other antelope including Eland, impala and Thomson’s gazelles, participate in the world’s greatest wildlife migration. This is the Great Migration.

In search of food and water, following the rains, vast herds move in a general clockwise direction through the Serengeti National Park. At one point, as shown in this photo, they cross the Mara River into Kenya’s Masai Mara Reserve. In the process, they must navigate waters often in flood; dodge crocodiles in search of dinner; fend off hungry lions and other big cat; and survive what to some might look like a dangerous stampede of beating hooves.

But while the migration may seem like nothing less than frenzied chaos, research has shown a herd of wildebeest – and their followers – possess what is known as ‘swarm intelligence’. So what may look like a stampede or out-of-control mob of heaving…