A large wildebeest herd creates a huge dust cloud as the animals charge toward a river in a bid to cross it before being caught by waiting crocodiles. /VCG Photo

Wildebeests breed at the end of the rainy season and the calves quickly become active and able to move with the herd. /VCG Photo

Wildebeests may drown or be eaten by crocodiles while crossing the river. But dramatic crossings like this can also result in crocodiles being stomped to death. /VCG Photo

Wildebeest herds migrate from the Serengeti in Tanzania to Maasai Mara National Reserve in southwest Kenya every year between July and October. /VCG Photo