Some trees have a most peculiar effect on those that visit them. The web of life in forests are so complex that we still do not understand all that is going on. But there is one creature enlisted by the trees whose life is so closely entwined that many forest trees would disappear without its cooperation.

Through their role in seed dispersal, spider monkeys have a capacity to help regenerate rainforests. It is believed that some seeds, like dialium, rely on being passed through a spider monkey’s stomach in order to regenerate.

Hanging by long tails from a high branch it is easy to see the black spider shape that's prompted the forest Indians to give the monkey its name. Spider monkeys spend their whole lives high up in the rainforest canopy eating fruit but as with everything it is not that simple. Their prehensile tail is the longest in the world.