The mountain gorillas live on the slopes of some of the steepest volcanoes in Africa. The volcanic range is part of the immense Albertine Rift Valley. This is part of the Rift Valley system that cuts down across the continent of Africa. Due to the volcanic activity and sinking and rising of parts of the continental plate, some of the most diverse and dramatic landscapes have formed as a result.
The flanks of the mountains and volcanoes in East Africa are covered with distinctive bands of vegetation that change as you move higher up the slopes. At lower altitudes there is dense forest, with montane forest where the trees are covered with moss and ferns above this. From the montane forest if you keep climbing you enter a zone of giant bamboo.
The bamboo grows in dense stands with very little else growing in between. The tall, sombre culms rise from a thick leaf litter that is churned into rich mud where hooves have trampled it. Sunlight is filtered by the overarching tapestry of leaves, and the result is a diffuse, cathedral like quality that is mostly silent, save for the occasional creaking or hollow knock when the wind gently stirs some shoots.
The rich, thick leaf litter that forms beneath the bamboo is a perfect home for many different creatures that like damp and dark places. We found one of these as we climbed up the steep path. I heard Paula cry out “Oh – what’s that? It’s disgusting!” Of course, being a good biologist she then picked it up. It was part of a (baby) giant earthworm.
These are one of several giant earthworms that can be found in the high altitude vegetation of the Albertine Rift. They can grow up to a several feet long, and are more hard and rubbery than their smaller more familiar cousins.
In some particularly damp places the earthworms even live on trees that have thick layers of moss growing on them! We only found baby earthworms crawling on the surface of the leaf litter. Their much bigger parents were hidden deeper in the thick humus. These worms were also much faster moving than the more common smaller species. They wriggled like snakes using their powerful muscles to twist out of my hands as I tried to photograph them.
After watching the magnificent earthworms, we walked on and on along the steep path through the bamboo. At one point there the leaves above shook vigorously and some of the bamboo stems waved about. A loud cry “Niiaooow- chuck” echoed from the crashing leaves. This was a Golden Monkey, a species endemic to the area. I only managed a few glimpses of the monkeys as they were extremely shy.
We carried on to the steepest section. Here you had to use all your strength and limbs to keep moving up the path. The mud was slippery and luckily the bamboo made nice handholds. After what seemed like ages we stopped to rest in a small glade.
As I searched for insects on flowers I noticed a flash of light zipping down from the canopy. I moved closer. It dropped again, this time to about eye level. A gentle wind picked rustled through the glade and the creature calmly drifted to and fro. What could this be? Who can levitate so effortlessly?
The breeze died down, and the creature came to rest perfectly still in mid-air! Now I could see that it was suspended by the thinnest of threads. This was a caterpillar absailing down from the canopy. Perhaps it was startled by a hungry bird and using its silken ‘safety rope’ had bungee-jumped off the leaves high above. I guess if you’re about to be eaten it’s worth the risk!
We had to move on, as there was still a lot of ground to cover before we got to the gorillas…
More about meeting the gorillas and the other incredible ‘dudus’ living with them soon!