We were booked on an afternoon trek so we sat around the lodge reading, writing the diary and watching red tailed and black and white colobus monkeys playing in the trees.
We then spend 5 fruitless hours wandering around the forest in the vain hope of spotting a chimp. All gone I'm afraid. So we begged to be allowed onto a morning trek the next day.
Jump forward a day......
Charles, our guide, took us off into the forest at first light, heading for one of the enormous fig trees that the chimps adore. This time we were lucky, and Charles spotted a group of chimps high in the canopy just getting out of their night-time nests.
We spent a few delightful minutes watching the chimps slowly wake up, have their morning pee (on our heads) eating a few figs and generally being cute and adorable.
Well to put it simply all hell broke loose.
Charles spotted the chimp group's alpha male (Mageze) high above us in the trees, and as we stood there he came down to the ground to check us out. After a couple of fake charges his attention was suddenly taken by something back up in the canopy.
A few seconds later he was up the tree and a smaller male chimp came flying out of it and landed with a crash at our feet. We initially thought "what a silly monkey, falling out a tree" before Charles started shouting "they are going to kill it, they are going to kill it"
As we watched with horror, the small chimp was then set upon by Mageze and his two lieutenants Ssebo and Flop. The next hour was simply an orgy of violence as the unfortunate chimp was dragged screaming through the forest, beaten with sticks, jumped on and at times eaten alive. Charles kept taking us in close, and it was clear the chimps were going to ignore us as they had a much more pressing engagement.
The three large males took it in turns to torture the younger male, as Charles tried to explain what was going on. We were constantly surrounded by other members of the group many of whom were screaming and crashing through the trees and undergrowth. He reckoned the youngster was from another chimp family and had simply been in the wrong place at the wrong time. And the excessive display of violence was as much a display of strength to others within their own group as it was an attack on others.
At times it was too hard to watch, the terrified cries of the youngster were piercing and heart rending. It was most difficult when the larger chimps started to bite lumps of flesh from the little one's arms and legs and then sit casually munching on the flesh.
In the beginning it was terrifying to be amongst the violence, but after only a few minutes we realised we were perfectly safe. Charles kept assuring us that even if a chimp charged at us we wouldn't be touched, no-one in Kibale has ever been hurt by a habituated chimp. It then became increasingly surreal, the sort of thing you might see on a nature documentary.
At times the beating stopped, as the big males drew breath and kept a watchful eye on the other chimps around them. Then it would start again, usually with the small chimp being dragged by an arm or leg through the undergrowth and being battered off trees and logs. The aggressors even used a small sapling dragging it down onto the smaller animal, much like a guilotine; over and over again. It got to the stage where we just hoped it would die and the punishment might end.
What did end, of course, was our allotted time with the group. And as we left the little chimp was still alive and screaming at the top of its lungs. We heard later that it eventually died in the traditional way that chimps are killed, the alpha male bites its testicles off and the poor creature bleeds to death.
Our trekking group was pretty sombre as we exited the forest and headed for our transport back to the visitor centre. Charles was highly excited - he'd only seen this behaviour twice before in his 18 years as a forest guide. He tried his best to calm us down and to lighten the mood by talking about his wife and children, but to be honest we were fairly traumatised.