@article {310455,
	title = {Optimisation of Nut-Cracking with Natural Hammers by Wild Chimpanzees},
	volume = {83},
	year = {1982},
	month = {1982},
	pages = {265-286},
	abstract = {<p>The chimpanzees of the Tai National Park, Ivory Coast, use sticks and stones to open 5 different species of nuts. In spite of an unfavourable availability of the material in the forest, the animals choose their tools adaptively. For cracking harder nuts, they use harder and heavier tools and transport tools more often and from farther away. Some aspects of the evolution of tool-use in primates are discussed. /// Les chimpanz{\'e}s du Parc National de Tai, C{\^o}te d{\textquoteright}Ivoire, utilisent des b{\^a}tons et des cailloux pour ouvrir 5 diff{\'e}rentes esp{\`e}ces de noix. Malgr{\'e} une disponibilit{\'e} d{\'e}favorable des mat{\'e}riaux dans la for{\^e}t, les animaux choisissent leurs outils de fa{\c c}on adaptive. Pour ouvrir les noix les plus dures, ils utilisent des outils plus durs et plus lourds et transportent les outils plus souvent et sur de plus grandes distances. Certains aspects de l{\textquoteright}{\'e}volution de l{\textquoteright}utilisation d{\textquoteright}outils chez les primates sont discut{\'e}s.</p>
},
	isbn = {00057959},
	url = {http://www.jstor.org/stable/4534230},
	author = {Boesch, C. and Boesch, H.}
}
