Anup Shah / Nile crocodile (Crocodylus niloticus) attacking a Thomson's gazelle (Eudorcas thomsonii) as it crosses the Mara River. Masai Mara National Reserve, Kenya, October 2009

Anup Shah / Nile crocodile (Crocodylus niloticus) attacking a Thomson's gazelle (Eudorcas thomsonii) as it crosses the Mara River. Masai Mara National Reserve, Kenya, October 2009

Anup Shah / Nile crocodile (Crocodylus niloticus) attacking a Wildebeest (Connochaetes taurinus) as it crosses the Mara River. Masai Mara National Reserve, Kenya, October 2009

Anup Shah / Nile crocodile (Crocodylus niloticus) attacking a Wildebeest (Connochaetes taurinus) as it crosses the Mara River. Masai Mara National Reserve, Kenya, September 2009

Ann & Steve Toon / Head portrait of Nile crocodile (Crocodylus niloticus) partically submerged, Crocodile Centre, St Lucia, KwaZulu Natal, South Africa. Captive

Ann & Steve Toon / Nile crocodile (Crocodylus niloticus) with jaws wide open, Kruger National Park, South Africa

Philip Dalton / Nile Crocodile (Crocodylus niloticus) approaching Common Zebra (Equus burchellii) as it swims across Mara river during migration, Masai Mara GR, Kenya

Philip Dalton / Nile Crocodile (Crocodylus niloticus) grabbing Common Zebra (Equus burchellii) as it swims across Mara river during migration, Masai Mara GR, Kenya

Philip Dalton / Nile Crocodile (Crocodylus niloticus) approaching Common Zebra (Equus burchellii) mother and foal as they swim across Mara river during migration, Masai Mara GR, Kenya

Philip Dalton / Nile Crocodile (Crocodylus niloticus) grabbing Common Zebra (Equus burchellii) as it swims across Mara river during migration, Masai Mara GR, Kenya

Andy Rouse / Common wildebeest (Connochaetes taurinus) on migration with Nile crocodile (Crocodylus niloticus) waiting in water, Masai Mara, Kenya

Andy Rouse / Nile crocodile (Crocodylus niloticus) chasing Wildebeest (Connochaetes taurinus) during migration crossing, Masai Mara, Kenya, Africa