our correspondent joins them in a mountain range of northern kenya. >> he knows this man range as well as any creature here. he has been coming here since he was a child, learning about the value of the forests to life itself. he is searching for a special treat, one with barkeep will boil -- a special tree, one with bark he will boil and give to a sick villager. this is the first comprehensive scientific survey of the mountains in northern kenya, and the researchers are digging deeper. this is what makes the matthews range so special. i am not just talking about the view. this is what scientists call us got island, tropical mountains surrounded by a red -- arid lowlands. scientists are only now starting to find out what is up here. >> with such a long time of seclusion, they expect to learn much about evolution in one of the last pristine patches of non force in east africa. today, they found a vampire bats, the furthest from because they have ever been seen. this shows how undisturbed because it really is. that does not mean it is safe. growing numbers of tribesmen are washing up on