In Mid 2008, I was fortunate enough to travel through several of the National Parks/Game Reserves of Tanzania as part of a photographic safari/workshop. One of the most remarkable things I saw during my time in the Serengeti was the crossing of the Mara River by migrating wildebeest.
This migration is one of the most notable of all nature's spectacles. I thought when I visited the Serengeti that it was probably out of season to witness this, but not all years are the same and seasons can vary a little. The wildebeest migrate from the southern part of the national park, north towards the border with Kenya. The critical point of this migration is when the animals have to cross the Mara River in order to continue north. Predators, notably crocodiles, gather at crossing points and await the prey.
We were out on the plains just to the north of the river when we heard that the wildebeest had gathered in large numbers on the southern side of the river and there was a chance they may cross. We dashed to the northern bank in time to see the crossing which proved to be one of the most amazing things I've ever seen. On the far bank there were tens of thousands of wildebeest. They would make their way down the steep bank of the river and then throw themselves into the water and swim, battling against the current and then clamber over slippery rocks and boulders to get to the far bank. They were jumping in at a rate of at least one every second. The northern bank and the rocks were so congested with animals that they were frantically trying to climb over the top of each other. Some couldn't get a foot hold and ended up crawling on their knees over the rocks, some falling back into the water and having to try repeatedly to get up.
The activity was so chaotic and frantic, that at times the water churned like a washing machine with water spray going in every direction. All the time there were crocodiles lying at the water's edge. We didn't see the crocs attack anything, they didn't have to. At the point where we observed all this, there were 7 or 8 wildebeest carcasses floating in the water, drowned or trampled to death. Goodness only knows how many die this way. The carcasses we observed were floating in eddies, no doubt many more would have been carried away by the current.
We observed this activity for about 30 minutes when suddenly they stopped crossing. Why we'll never know, a change of wind direction? The sun went behind a cloud? Don't know but it was so abrupt that it was as though someone had thrown a switch. Those thousands of animals still on the southern side gradually moved back from the river, presumably to try again at a later time or at a different point on the river.
Thinking that the activity was over we then noticed that about 200 to 300 metres upstream the wildebeest had started crossing the river at that point. We moved our vehicles closer and watched in awe as the spectacle played out again for another 30 minutes at least. In all we must have seen 4 or 5 thousand animals cross.
It was only afterwards that I really appreciated just how lucky we'd been. One of our drivers has been doing these safaris full time for the last 30 years and only witnessed the river crossing 4 times. Another of our drivers is into his 10th year of safari driving and had only seen it once before and the previous sighting wasn't nearly as good as this.
This particular image was cropped from the full frame image taken on the Canon 5D with 500mm lens at F 5.6, shutter speed 1/2000 second at ISO 100. The high shutter speed was required to capture the splashing water. Further images from this event can be seen as part of the "Crossing the Mara" gallery.