Orangutan At Indonesia Safari Park, Prigen-Indonesia Stock Photo

Orangutan hands have four long fingers but a dramatically shorter opposable thumb for a strong grip on branches as they travel high in the trees. The resting configuration of the fingers is curved, creating a suspensory hook grip. With the thumb out of the way, the fingers (and hands) can grip securely around objects with a small diameter by resting the tops of the fingers against the inside of the palm, thus creating a double-locked grip.[