Sizing up the herd we reckon that if they all go it could take half and hour. Waves of animals gather at the edge of the cliff and then move toward and away from the water. At times even hundreds of wildebeests will fall in line moving away from the crossing and each time they do I despair, even though with all those crocs, we are in effect egging on a tiny percentage of wildebeests to their deaths.
This is a single photo HDR, re-exposed +2, +1, 0, -1, -2 in Bridge, recombined in Photomatix, finished in Photoshop. Click the photo for a bigger version.