A report published recently on the Public Library of Science website reveals fascinating evidence about the innovative use of tools and abstract thinking among gorillas – findings that reminds us not to underestimate our animal ancestors. Biologists have long distinguished humans from other primates in terms of their ability to design and utilize tools.

While it's been known for some time that chimpanzees use sticks to scoop termites from logs, and rocks to crack open nuts, a team led by Thomas Breuer of the Wildlife Conservation Society has provided the first photographic evidence of amazing tool-dexterity among wild gorillas in the Republic of Congo.

The team observed one gorilla using a tree limb to asses the depth of water before wading into it; another gorilla created a bridge to traverse a puddle – evidence of abstract reasoning among primates that hasn't been observed before. For more info on primate behavior, visit the website of renowned primatologist Jane Goodall.

Photo credit: pin.primate.wisc.edu