Possible tool use in a mountain gorilla.

Here we report a description of putative tool use in wild mountain gorillas. At the Dian Fossey Gorilla Fund's Karisoke Research Center in Volcanoes National Park (Rwanda), an adult female was observed using a bamboo culm as a ladder for her offspring. This is one of only a few documented cases of possible tool use in wild gorillas, although tool use behavior is commonly observed in captive gorillas. Although the behavior observed may have been incidental, the present report in combination with previous evidence (Breuer et al., 2005) suggests that tool use in gorillas occurs outside the context of food acquisition and may be directed at overcoming physical obstacles in complex rugged microhabitats such as bamboo forest and swamps.