Katarina Almeida-Warren1,2, Volker Sommer1, Alex K Piel3,4, Alejandra Pascual-Garrido5. 1. Department of Anthropology, University College London, London, WC1 E6BT, United Kingdom. 2. Institute of Cognitive and Evolutionary Anthropology, University of Oxford, Oxford, OX2 6PN, United Kingdom. 3. School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, L3 3AF, United Kingdom. 4. Ugalla Primate Project, PO Box 108, Uvinza, Tanzania. 5. RLAHA, School of Archaeology, Leverhulme Trust Early Career Fellow, University of Oxford, Oxford, OX1 3QY, United Kingdom.
Abstract
OBJECTIVES: Chimpanzee termite fishing has been studied for decades, yet the selective processes preceding the manufacture of fishing tools remain largely unexplored. We investigate raw material selection and potential evidence of forward planning in the chimpanzees of Issa valley, western Tanzania. MATERIALS AND METHODS: Using traditional archaeological methods, we surveyed the location of plants from where chimpanzees sourced raw material to manufacture termite fishing tools, relative to targeted mounds. We measured raw material abundance to test for availability and selection. Statistics included Chi-Squared, two-tailed Wilcoxon, and Kruskall-Wallace tests. RESULTS: Issa chimpanzees manufactured extraction tools only from bark, despite availability of other suitable materials (e.g., twigs), and selected particular plant species as raw material sources, which they often also exploit for food. Most plants were sourced 1-16 m away from the mound, with a maximum of 33 m. The line of sight from the targeted mound was obscured for a quarter of these plants. DISCUSSION: The exclusive use of bark tools despite availability of other suitable materials indicates a possible cultural preference. The fact that Issa chimpanzees select specific plant species and travel some distance to source them suggests some degree of selectivity and, potentially, forward planning. Our results have implications for the reconstruction of early hominin behaviors, particularly with regard to the use of perishable tools, which remain archaeologically invisible.
OBJECTIVES:Chimpanzee termite fishing has been studied for decades, yet the selective processes preceding the manufacture of fishing tools remain largely unexplored. We investigate raw material selection and potential evidence of forward planning in the chimpanzees of Issa valley, western Tanzania. MATERIALS AND METHODS: Using traditional archaeological methods, we surveyed the location of plants from where chimpanzees sourced raw material to manufacture termite fishing tools, relative to targeted mounds. We measured raw material abundance to test for availability and selection. Statistics included Chi-Squared, two-tailed Wilcoxon, and Kruskall-Wallace tests. RESULTS: Issa chimpanzees manufactured extraction tools only from bark, despite availability of other suitable materials (e.g., twigs), and selected particular plant species as raw material sources, which they often also exploit for food. Most plants were sourced 1-16 m away from the mound, with a maximum of 33 m. The line of sight from the targeted mound was obscured for a quarter of these plants. DISCUSSION: The exclusive use of bark tools despite availability of other suitable materials indicates a possible cultural preference. The fact that Issa chimpanzees select specific plant species and travel some distance to source them suggests some degree of selectivity and, potentially, forward planning. Our results have implications for the reconstruction of early hominin behaviors, particularly with regard to the use of perishable tools, which remain archaeologically invisible.
Authors: Antonio J Osuna-Mascaró; Camila Ortiz; Caroline Stolz; Stephanie Musgrave; Crickette M Sanz; David B Morgan; Dorothy M Fragaszy Journal: Am J Primatol Date: 2020-11-16 Impact factor: 2.371