3 - Orangutan
The great apes are considered the smartest creatures after humans. Of course, humans are biased in this regard, but the intellectual capacity of the great apes is difficult to deny. Among them, orangutans stand out as being especially gifted in the brains department. They have a strong culture and system of communication, and many have been observed to use tools in the wild. Orangutans live in widely scattered communities and form strong social bonds, which may be the key to their advanced cognitive skills. Females remain with their young for many years, teaching them all they need to survive in the forest.