As many friends, colleagues and clients know, I've done this for over a decade now, helping to raise thousands for the gorillas (see pictures, videos and other links at http://www.ozaru.net/bujinkan/ozaru-run.html).

All four types of gorillas are critically endangered. The Gorilla Organization helps protect them by working on the ground with local people, combining education programmes with support for the rangers who constantly battle poachers and other threats. You can learn more via http://gorillas.org/