In the Serena Valley of the Serengeti in Tanzania, we came upon these two Defassa Waterbucks at war. The sound was impressive, and the fight was brutal. The fight had started before we spotted their horns far off in the high grass. We parked on the road fairly far from them, and watched in awe as they came closer and closer to our vehicle. We watched the fight for a full 5 minutes as it crossed 2 roads and meandered across huge tracts of plains. The animal on the left, the darker one, eventually won out, and the lighter colored one took off as fast as he could run. We followed them for about 1/2 a mile before we lost them in a wooded area far from any roads. The sounds of their horns clashing and their heavy breathing and grunting will stay with me for a long time.