Crocodiles in Tanzania — Prehistoric Predators

The Nile crocodile is Africa's largest reptile, growing up to 6 meters (20 feet) and weighing over 1,000 kg. They are ancient — virtually unchanged for 200 million years. And they are perfectly adapted killing machines.

Tanzania's rivers hold some of the densest crocodile populations in Africa. The Grumeti, Mara, and Rufiji rivers are crocodile strongholds. During the Great Migration, they feast on wildebeest attempting river crossings — the most dramatic predator-prey spectacle on Earth.

Crocodiles hunt by remaining completely motionless, with only their eyes and nostrils above water. When prey approaches the water's edge, they explode upward with terrifying speed. The bite force of a large Nile crocodile exceeds 5,000 psi — enough to crush a wildebeest skull instantly.

They do not chew. They tear off chunks by spinning in the water (the "death roll") or swallow prey whole. Wildebeest are typically drowned and stashed under submerged branches for later consumption.

• Serengeti (Grumeti & Mara Rivers) — During migration season, crocodiles line the banks waiting for crossings.
• Nyerere National Park (Selous) — The Rufiji River has enormous crocodiles. Boat safaris offer incredible viewing.
• Katavi — Crocodiles dig caves in riverbanks to survive the dry season — a unique behavior.
• Serengeti western corridor — The Grumeti River crossing in June is crocodile prime time.

Crocodiles are the villains of the Great Migration — and the heroes of the river ecosystem. When hundreds of thousands of wildebeest cross the Grumeti and Mara rivers, crocodiles gorge themselves, storing fat for months. A single large crocodile can eat half its body weight in one feeding session.

The Mara River crossing in July-October offers the most dramatic crocodile action. Crocodiles lie in wait at narrow crossing points, launching explosive attacks on panicked wildebeest.

Nile crocodiles are opportunistic man-eaters. They kill an estimated 200-300 people per year across Africa. In Tanzania, most attacks occur near rural villages where people collect water or wash clothes.

On safari, you are safe. Crocodiles do not attack vehicles. But never swim in rivers, and keep a safe distance from the water's edge on foot.

Read our Mara River Crossing guide or plan your safari.