First Observation of Tool Use in Wild Gorillas
For the first time, scientists have observed and photographed wild gorillas using tools, including the moment Leah – the nickname used by scientists – used a stick to test the depth of a pool before wading into it.
Female Leah first looked at the new elephant pool and the branch she later used as the walking stick, and entered the water without the tool (not shown). After re-entering the pool and taking the branch with her right hand, she walked bipedally 8-10m into the water, frequently testing water deepness.
All other species of great apes, including chimpanzees, bonobos and orang-utans, have been observed using tools in the wild, but never gorillas until now.
Original article (source of images above) is here: PLoS Biology.