Driven by pure instinct, migrating wildebeest sometimes leap into dry riverbeds as if they were full of water.

The Great Migration involves over 1.5 million wildebeest traveling a 500-mile loop through the Serengeti in Tanzania and the Maasai Mara in Kenya. This movement is dictated by the search for green pastures and water, guided by the sound of distant thunderstorms and the smell of rain. Research by the Serengeti Lion Project and other ecological studies shows that the herd's behavior is governed by 'swarm intelligence' rather than individual decision-making.When the leaders of the herd reach a river, the thousands of animals pressing from behind create a physical and psychological momentum that is nearly impossible to stop. This phenomenon, often called a 'stampede effect,' means that if the leading animals perceive a traditional crossing point, they will jump regardless of the current water level. In particularly dry years, this results in mass injuries or death as animals land on dry rocks or shallow silt.Ecologists have documented that these river crossings are the most dangerous part of the journey, with an estimated 6,250 wildebeest drowning or being crushed annually at the Mara River alone. The instinctual drive is so ancient and rigid that it does not always account for rapid environmental shifts or seasonal droughts. This behavior highlights the trade-off in evolution where a highly successful collective instinct can occasionally lead to individual catastrophe.