ROCA (RObotics, Cognition, and Archaeology) is an ontology designed to describe behavioural processes in the context of robotics, archaeology, and primatilogy, with a focus on tool use and tool making.
It is inspired by the SOMA, DOLCE, and OpenCyc ontologies.
End product resulting from modification of a physical mass to fulfil a useful purpose
Parts change their relationship with one another when form is used
Target of the action is modified formally.
Form that controls the movement of prey or protects it to the users advantage.
Facility for which the physical presence of user is essential for functioning
Facility that functions in the absence of user
Hand-manipulated subsistant that customarily is used to impinge on passes incapable of significant motion and is relatively harmless to the user
Meta event do not describe specific events but things such as the start of an event, its end, pausing, and so on.
Natural form, used in place or withdrawn from a habitat, that is used without prior modification
Direct observation of an event.
Oswalt, Wendell H. 1976. An Anthropological Analysis of Food-Getting Technology. New York: John Wiley & Sons.
Retains some physical form before and during use
Extrasomatic form that is removed from a natural context or is manufactured and is applied directly to obtain food
Integrated, physically distinct, and unique structural configuration that contributes to the form of a finished artifact
Form that is handled when in use and is designed to kill or maim species capable of motion
Lawick-Goodall, Jane Van, H. Van Lawick, and C. Packer. 1973. “Tool-Use in Free-Living Baboons in the Gombe National Park, Tanzania.” Nature 241 (5386): 212–13. https://doi.org/10.1038/241212a0
Lawick-Goodall, Jane Van, H. Van Lawick, and C. Packer. 1973. “Tool-Use in Free-Living Baboons in the Gombe National Park, Tanzania.” Nature 241 (5386): 212–13. https://doi.org/10.1038/241212a2
van Lawick-Goodall, J., van Lawick, H. and Packer, C., 1973. Tool-use in free living baboons in the Gombe National Park, Tanzania. Nature 241, 212-213.
van Lawick-Goodall, J., van Lawick, H. and Packer, C., 1973. Tool-use in free living baboons in the Gombe National Park, Tanzania. Nature 241, 212-213.
Falótico, Tiago, and Eduardo B. Ottoni. “Sexual Bias in Probe Tool Manufacture and Use by Wild Bearded Capuchin Monkeys.” Behavioural Processes 108 (October 1, 2014): 117–22. https://doi.org/10.1016/j.beproc.2014.09.036
Boinski, S., 1988. Use of a club by a wild white-faced capuchin (Cebus capucinus) to attack a venomous snake (Bothrops asper). Am. J. Primatol. 14, 177-179.
Falótico, Tiago, and Eduardo B. Ottoni. “Sexual Bias in Probe Tool Manufacture and Use by Wild Bearded Capuchin Monkeys.” Behavioural Processes 108 (October 1, 2014): 117–22. https://doi.org/10.1016/j.beproc.2014.09.038
Proffitt, Tomos, Lydia V. Luncz, Tiago Falótico, Eduardo B. Ottoni, Ignacio de la Torre, and Michael Haslam. “Wild Monkeys Flake Stone Tools.” Nature 539, no. 7627 (November 2016): 85–88. https://doi.org/10.1038/nature20112
Falótico, Tiago, and Eduardo B. Ottoni. “Sexual Bias in Probe Tool Manufacture and Use by Wild Bearded Capuchin Monkeys.” Behavioural Processes 108 (October 1, 2014): 117–22. https://doi.org/10.1016/j.beproc.2014.09.037
Falótico, Tiago, and Eduardo B. Ottoni. “Sexual Bias in Probe Tool Manufacture and Use by Wild Bearded Capuchin Monkeys.” Behavioural Processes 108 (October 1, 2014): 117–22. https://doi.org/10.1016/j.beproc.2014.09.037
Techniques Used by Bearded Capuchin Monkeys ( Sapajus libidinosus ) to Access Water in a Semi-Arid Environment of North-Eastern Brazil
Techniques Used by Bearded Capuchin Monkeys ( Sapajus libidinosus ) to Access Water in a Semi-Arid Environment of North-Eastern Brazil
Nasal probe and toothpick tool use by a wild female bearded capuchin (Sapajus libidinosus)
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
“Boinski, S., Quatrone, R.P. and Swartz, H., 2000. Substrate and tool use by brown capuchins in Suriname: ecological contexts and cognitive bases. Am. Anthropol. 102, 741-761.”
“Boinski, S., Quatrone, R.P. and Swartz, H., 2000. Substrate and tool use by brown capuchins in Suriname: ecological contexts and cognitive bases. Am. Anthropol. 102, 741-761.”
“Boinski, S., Quatrone, R.P. and Swartz, H., 2000. Substrate and tool use by brown capuchins in Suriname: ecological contexts and cognitive bases. Am. Anthropol. 102, 741-761.”
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
Tool Use in Wild Capuchin Monkeys(Cebus albifrons trinitatis)
Fernandes, M.E., 1991. Tool use and predation of oysters (Crassostrea rhizophorae) by the tufted capuchin, Cebus apella apella, in brackish water mangrove swamps. Primates 32, 529-531.
Tool use in urban populations of capuchin monkeys Sapajus spp. (Primates: Cebidae)DOI: 10.1590/S1984-46702014000500012
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
“Boinski, S., Quatrone, R.P. and Swartz, H., 2000. Substrate and tool use by brown capuchins in Suriname: ecological contexts and cognitive bases. Am. Anthropol. 102, 741-761.”
Boinski, S., 1988. Use of a club by a wild white-faced capuchin (Cebus capucinus) to attack a venomous snake (Bothrops asper). Am. J. Primatol. 14, 177-179.
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
“Boinski, S., Quatrone, R.P. and Swartz, H., 2000. Substrate and tool use by brown capuchins in Suriname: ecological contexts and cognitive bases. Am. Anthropol. 102, 741-761.”
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
Izawa, K. and Mizuno, A., 1977. Palm-fruit cracking behaviour of wild black-capped capuchin (Cebus apella). Primates 18, 773-792.
Tool use in urban populations of capuchin monkeys Sapajus spp. (Primates: Cebidae)DOI: 10.1590/S1984-46702014000500012
The enhanced tool-kit of two groups of wild bearded capuchin monkeys in the Caatinga: tool making, associative use, and secondary tools
Critically endangered blonde capuchins fish for termites and use new techniques to accomplish the task doi:10.1098/rsbl.2011.0034
Techniques Used by Bearded Capuchin Monkeys ( Sapajus libidinosus ) to Access Water in a Semi-Arid Environment of North-Eastern Brazil
Wild Capuchin Monkeys (Cebus libidinosus) Use Anvils and Stone Pounding Tools
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chevalier-Skolnikoff, S., 1990. Tool use by wild cebus monkeys at Santa Rosa National Park, Costa Rica. Primates 31, 375-383.
Chimpanzee tool use for honey and termite extraction in Central Africa J. Michael Fay, Richard W. Carroll
Aspects of transmission of tool-use in wild chimpanzees
Chimpanzees plan their tool use
Chimpanzees plan their tool use
Chimpanzees plan their tool use
Boesch, Christophe, Josephine Head, and Martha M. Robbins. 2009. “Complex Tool Sets for Honey Extraction among Chimpanzees in Loango National Park, Gabon.” Journal of Human Evolution 56 (6): 560–69.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Use of tool sets by chimpanzees for multiple purposes in Moukalaba-Doudou National Park, Gabon
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
The leaf-clipping Display: A newly-discovered Expressive Gesture in wild chimpanzees
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Boesch, Christophe, Josephine Head, and Martha M. Robbins. 2009. “Complex Tool Sets for Honey Extraction among Chimpanzees in Loango National Park, Gabon.” Journal of Human Evolution 56 (6): 560–69.
Boesch, Christophe, Josephine Head, and Martha M. Robbins. 2009. “Complex Tool Sets for Honey Extraction among Chimpanzees in Loango National Park, Gabon.” Journal of Human Evolution 56 (6): 560–69.
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
Brewer, S. M., and W. C. McGrew. 1990. “Chimpanzee Use of a Tool-Set to Get Honey.” Folia Primatologica; International Journal of Primatology 54 (1–2): 100–104
Boesch, Christophe, Josephine Head, and Martha M. Robbins. 2009. “Complex Tool Sets for Honey Extraction among Chimpanzees in Loango National Park, Gabon.” Journal of Human Evolution 56 (6): 560–69.
Boesch, Christophe, Josephine Head, and Martha M. Robbins. 2009. “Complex Tool Sets for Honey Extraction among Chimpanzees in Loango National Park, Gabon.” Journal of Human Evolution 56 (6): 560–69.
Supplementary Material for "First evidence of chimpanzee extractive tool use in Cantanhez, Guinea-Bissau: cross-community variation in honey dipping”, Bessa Joana, Hockings Kimberley, Biro Dora, 2021
Supplementary Material for "First evidence of chimpanzee extractive tool use in Cantanhez, Guinea-Bissau: cross-community variation in honey dipping”, Bessa Joana, Hockings Kimberley, Biro Dora, 2022
Supplementary Material for "First evidence of chimpanzee extractive tool use in Cantanhez, Guinea-Bissau: cross-community variation in honey dipping”, Bessa Joana, Hockings Kimberley, Biro Dora, 2023
Supplementary Material for "First evidence of chimpanzee extractive tool use in Cantanhez, Guinea-Bissau: cross-community variation in honey dipping”, Bessa Joana, Hockings Kimberley, Biro Dora, 2024
Supplementary Material for "First evidence of chimpanzee extractive tool use in Cantanhez, Guinea-Bissau: cross-community variation in honey dipping”, Bessa Joana, Hockings Kimberley, Biro Dora, 2025
Bermejo, M. and Illera, G., 1999. Tool-set for termite-fishing and honey extraction by wild chimpanzees in the Lossi Forest, Congo. Primates 40, 619-627.
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Bermejo, M. and Illera, G., 1999. Tool-set for termite-fishing and honey extraction by wild chimpanzees in the Lossi Forest, Congo. Primates 40, 619-627.
Bermejo, M. and Illera, G., 1999. Tool-set for termite-fishing and honey extraction by wild chimpanzees in the Lossi Forest, Congo. Primates 40, 619-627.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Boesch, Christophe, Josephine Head, and Martha M. Robbins. 2009. “Complex Tool Sets for Honey Extraction among Chimpanzees in Loango National Park, Gabon.” Journal of Human Evolution 56 (6): 560–69.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Invention and modification of a new tool use behaviour: ant-fishing in trees by a wild chimpanzee (Pan troglodytes verus) at Bossou, Guniea.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
“Beatty, H., 1951. A note on the behaviour of the chimpanzee. J. Mammal 32(1), 118.”
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Chimpanzee Tool Use to Clear a Blocked Nasal Passage
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Chimpanzee tool technology in the Goualougo Triangle, Republic of Congo
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Sex differences in the use of natural hammers by wild chimpanzees
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
Tool-using and -making behavior in wild chimpanzees at Bossou, Guinea
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Tool-using and -making behavior in wild chimpanzees at Bossou, Guinea
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Chimpanzee tool technology in the Goualougo Triangle, Republic of Congo
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Chimpanzee Tool Use to Clear a Blocked Nasal Passage
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Use of tool sets by chimpanzees for multiple purposes in Moukalaba-Doudou National Park, Gabon
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Use of tool sets by chimpanzees for multiple purposes in Moukalaba-Doudou National Park, Gabon
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Tool-using and -making behavior in wild chimpanzees at Bossou, Guinea
Pestle-pounding behaviour of wild chimpanzees at Bossou, Guinea: a newly observed tool-using behaviour
Tool-using and -making behavior in wild chimpanzees at Bossou, Guinea
Tool-use by chimpanzees (Pan troglodytes troglodytes) in the Lopé Reserve, Gabon
Tool-use by chimpanzees (Pan troglodytes troglodytes) in the Lopé Reserve, Gabon
Chimpanzee tool technology in the Goualougo Triangle, Republic of Congo
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Leaf-folding behaviour for drinking water by wild chimpanzees (Pan troglodytes verus) at Bossou, Guinea
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
Pruetz, J.D., and Bertolani, P., 2007. Savanna Chimpanzees, Pan troglodytes verus, hunt with Tools. Current Biology 17(5), 412–417.
Tool-use for drinking water by immature chimpanzees of Mahale: prevalence of an unessential behavior
Supplementary Material for "First evidence of chimpanzee extractive tool use in Cantanhez, Guinea-Bissau: cross-community variation in honey dipping”, Bessa Joana, Hockings Kimberley, Biro Dora, 2021
Fay, J.M. and Carroll, R.W., 1994. Chimpanzee tool use for honey and termite extraction in Central Africa. Am. J. Primatol. 34: 309-317.
Alp, R., 1997. “Stepping-sticks” and “seat-sticks”: new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. Am. J. Primatol (41) 45-52. https://pubmed.ncbi.nlm.nih.gov/9064197/
Hirata, S., Myowa, M. and Matsuzawa, T., 1998. Use of leaves as cushions to sit on wet ground by wild chimpanzees. Am. J. Primatol. 44, 215-220.
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Sex differences in the use of natural hammers by wild chimpanzees
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Seasonal Changes in the Techniques Employed by Wild Chimpanzees in the Mahale Mountains, Tanzania, to Feed on Termites (Pseudacanthotermes spiniger)
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Tool use by chimpanzees at Ngogo, Kibale National Park, Uganda
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Goodall, J., 1964. Tool-using and aimed throwing in a community of free-living chimpanzees. Nature 201, 1264–1266.
Chimpanzee tool technology in the Goualougo Triangle, Republic of Congo
Invention and modification of a new tool use behaviour: ant-fishing in trees by a wild chimpanzee (Pan troglodytes verus) at Bossou, Guniea.
Tool use by wild chimpanzees in feeding upon driver ants.
Tool-using and -making behavior in wild chimpanzees at Bossou, Guinea
TOOL-USING AND AIMED THROWING IN A COMMUNITY OF FREE-LIVING CHIMPANZEES
Tool use during display behaviour in wild Cross River gorillas
Tool use during display behaviour in wild Cross River gorillas
Van Lawick-Goodall, Jane. 1971. “Tool-Using in Primates and Other Vertebrates.” In Advances in the Study of Behavior, edited by Daniel S. Lehrman, Robert A. Hinde, and Evelyn Shaw, 3:195–249. Academic Press. https://doi.org/10.1016/S0065-3454(08)60157-6.
Tool Use for Food Acquisition in a Wild Mountain Gorilla(Gorilla beringei beringei)
First observation of tool use in wild gorillas
Possible tool use in a mountain gorilla
Tool use during display behaviour in wild Cross River gorillas
First observation of tool use in wild gorillas
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Scheurer, J., and B. Thierry. 2006. “A Further Food-Washing Tradition in Japanese Macaques (Macaca Fuscata).” Primates.
Carpenter, Alfred. 1887. “Monkeys Opening Oysters.” Nature 36 (916): 53–53. https://doi.org/10.1038/036053d0.
Complex Tool Manufacture by a Wild Bonnet Macaque, Macaca radiata
Chiang, M., 1967. Use of tools by wild macaque monkeys in Singapore. Nature 214, 1258-1259.
Chiang, M., 1967. Use of tools by wild macaque monkeys in Singapore. Nature 214, 1258-1259.
Chiang, M., 1967. Use of tools by wild macaque monkeys in Singapore. Nature 214, 1258-1259.
Chiang, M., 1967. Use of tools by wild macaque monkeys in Singapore. Nature 214, 1258-1259.
Fox, E.A. and Bin’Muhammad, I., 2002. New tool use by wild Sumatran orangutans (Pongo pygmaeus abelii). Am. J. Phys. Anthropol. 119, 186-188.
Fox, E.A. and Bin’Muhammad, I., 2002. New tool use by wild Sumatran orangutans (Pongo pygmaeus abelii). Am. J. Phys. Anthropol. 119, 186-188.
Galdikas, B.M., 1982. Orang-utan tool-use at Tanjung Puting Reserve, Central Indonesian Borneo (Kalimantan Tengah). J. Human Evol. 10, 19-33.
An Unusual Instance of Tool-use Among Wild Orang-utans in Tanjung Puting Reserve, Indonesian Borneo
Object manipulation by wild red colobus monkeys living in the Abuko Nature Reserve, The Gambia
Object manipulation by wild red colobus monkeys living in the Abuko Nature Reserve, The Gambia
Object manipulation by wild red colobus monkeys living in the Abuko Nature Reserve, The Gambia
Object manipulation by wild red colobus monkeys living in the Abuko Nature Reserve, The Gambia
Tool Use by a Red Howler Monkey (Alouatta seniculus) Towards a Two-toed Sloth (Choloepus didactylus)
Tool use in wild spider monkeys (Ateles geoffroyi)
Tool use in wild spider monkeys (Ateles geoffroyi)
Tool use in wild spider monkeys (Ateles geoffroyi)
One three-year-old female, however, picked up a fairly large stone with which she repeatedly and forcefully rubbed at her muzzle in an attempt to remove the dried juice. Clover (3 yr old female baboon) using a stone to wipe her mouth after feeding.
The second incident, observed about one month later, involved an adult male of a different (neighbouring) troop. He cut his lower lip during a fight, causing blood and saliva to run down his chin. When, presumably, the blood had begun to coagulate, the baboon looked around, reached out for an old piece of maize kernel (the troop was foraging around human habitation) and with this gently wiped away most of the blood from his lower lip.
“One three-year-old female, however, picked up a fairly large stone with which she repeatedly and forcefully rubbed at her muzzle in an attempt to remove the dried juice.”
“The second incident, observed about one month later, involved an adult male of a different (neighbouring) troop. He cut his lower lip during a fight, causing blood and saliva to run down his chin. When, presumably, the blood had begun to coagulate, the baboon looked around, reached out for an old piece of maize kernel (the troop was foraging around human habitation) and with this gently wiped away most of the blood from his lower lip.”
A typical probing episode starts with the monkey inspecting the possible nest/hiding place and then going to a near tree to take/make a probe. The monkey breaks apart a small branch from a tree and, while returning, the branch is trimmed. After reaching the target place, the monkey starts to probe with the stick, inserting it into the prey’s hiding place and moving it in and out. When successful, the prey comes out and the monkey may catch it (Supplementary movie 1). Or, in the case of honey, the monkey simply licks the dipped probe.
After threatening for another minute, the adult male came to the ground 2 m away from the spot that was arousing attention, jumped up and down repeatedly on all fours while barking, and then picked up a club-like dead branch (70 x 7 cm) from the ground. Between 11:38 and 11:54 h, the adult male struck the same patch of ground (approx. 1 m wide) at least 55 times. Blows were delivered with the branch gripped in the right hand 20-30 cm from the end while the animal stood bipedally or was supported by one forelimb and the hindlimbs. Usually the branch was raised from the ground to an upright position with a side arm stroke; the down stroke was overhand. The branch was often dropped following a blow.”
One stick tool was used by an adult male, without the removal of its terminal branches, to scatter and take down bees (Apis sp) from a honeycomb. The monkey ate some of the bees.
a capuchin place a newly fractured stone flake on top of another stone, and then strike it with a hammer in a manner resembling chimpanzee nut-cracking or human bipolar reduction
individuals using sticks to groom themselves (...) in another, an adult female used a stick to scratch/poke the individual she was grooming.
individuals using sticks to groom themselves. In one case an adult male scratched his own head (Supplementary movie 3) and in another, an adult female used a stick to scratch/poke the individual she was grooming.
“ Tool and Tail Use to Collect Rainwater Accumulated in a Tree Hole: These events (direct observation: n = 2) were carried out by 1 adult female, following the only rainy day during the month of October 2014 (rainfall = 70 mm). During the first event, the female anchored her body to a branch of an undetermined tree species using her tail and then used one of her hands to dip a branch with a leaf at one of its extremities into a hole (approx. 5 cm in diameter) in between the base of several branches of the tree. The female left the extremity of the branch with the leaf inside the hole for no more than 3 s then pulled it out very fast with both hands, bringing the leaf to her mouth and sucking it ( Fig. 2 a). Subsequently, the female left the tree, but we could not see whether she discarded the branch. Approximately 3 h afterwards, the female repositioned herself at the same tree and inserted her tail into the hole with accumulated rain water. After about 20 s, she extracted her wet tail and then licked the water which had adhered to her fur ( Fig. 2 b).”
“ Use of Liquid Endosperm of Unripe Palm Nuts: To retrieve the liquid endosperm from immature fruits of the Syagrus sp. palm, 1 adult male, anchored to a branch by his hind limbs, collected a single unripe nut with his hands and peeled it with his teeth and hands until he found the germ pore of the fruit. The monkey then opened up the hole with his teeth and drank the liquid endosperm. The animal consumed the liquid endosperm from 5 fruits over the course of this single foraging bout. The indirect observations consisted of unripe nuts with the same characteristics as the ones left after the male had drunk the liquid endosperm (indirect observation: n = 3; Fig. 2 d). The direct observation on the use of liquid endosperm was made in August ( n = 1), and the indirect observations in August, September, and November of 2014 (1/month).”
“ We recorded a total of 13 nasal probe insertions (Fig. 1b), ten of which were followed by one or two sneezes. The nasal probe insertion was done very carefully, and in each case insertion ceased if a sneeze was triggered. Aca´cia would then vigorously rub her nose with her hand and arm. Only a small volume of mucus, if any, was discharged with each triggered sneeze. Nasal probing produced an average of just over one sneeze per use, and the capuchin licked the tool afterwards on fewer than half of the 13 occasions (Table 1). Licking was more common during toothpick tool use, which never elicited a sneeze. Tooth picking (Fig. 1c) was performed with a quicker motion, but still with care taken to repeatedly place the tip of the probe at the same location inside the mouth. Aca´cia appeared to be working at, or rubbing the base of the teeth or her gums on the upper right side of her mouth, beneath her lip. Once the tool was in place, she worked the handheld end of the tool rapidly back and forth. We recorded seven instances of toothpick tool use, all of which involved two of the more robust stick probe tools (Tools B and D) rather than the flexible grass tool. Aca´cia used one of the probes (Tool B) to perform both the nasal probe and toothpick behaviours, interspersing one with the other. She regularly inspected and licked the tools during both types of tool use (Fig. 1d), although we were unable to determine whether this was to remove dislodged material from the tool’s tip or for some other purpose.”
“(...) a fruit of cumare against a guadua (...). Another capuchin tried striking another fruit twice and also abandoned it. Just after that, when three strokes were heard 200 to 300 m away, the two capuchins moved in that direction.”
“A capuchin struck a fruit of cumare against a guadua three times but abandoned it immediately. Another capuchin tried striking another fruit twice and also abandoned it. Just after that, when three strokes were heard 200 to 300 m away, the two capuchins moved in that direction.”
“A juvenile female C. apella, approximately two years of age, provides another representative instance of pyxidia processing in Suriname. She sat on a branch 25 cm in diameter, striking an unripe (green) Lecythis congestifolia fruit on the branch using a two-handed grip. Her prehensile tail curled about the branch behind her, apparently to provide stability. The observer watched the pyxidium strike the branch at least 65 times before breaking into two pieces. She then proceeded to eat the large seeds out of the section of capsule held in each hand as if she were eating from an ice cream cone. [...] The capuchin stopped every five to eight strokes, carefully inspected the damage produced, and occasionally gnawed at the small portions of seeds then exposed. As with the adult capuchins processing Brazil nuts, no inept or misdirected motion by the juvenile capuchin was detected. Every blow was calmly and deliberately delivered, as were the slow, smooth, and careful motions with which the pyxidium was rotated during the intervals of inspection.”
“An immature capuchin, for example, probably one to two years old, unsuccessfully attempted to harvest seeds from intact C. oblongifolia fruit by substrate use: breaking the fruit open against the ground. The technique employed was reminiscent of the usual two-handed blow employed by adults. The immature capuchin held the pyxidium in both hands and made the same downward motion with its arms that larger and more mature animals use. However, this juvenile was on the ground and while making the smashing motion would jump simultaneously in the air. At the end of its swing, the juvenile tossed the fruit in the air while throwing itself on the ground. Despite the intense effort of the juvenile, the pyxidium did not contact any hard substrate. The small capuchin repeated this procedure at least three times before apparently noticing how close the human observer was and scurrying up the nearest tree without the fruit.”
“Another illustration of an immature pairing correct motor skills with an inappropriate pounding substrate was an infant male, approximately 10-12 months old, who harvested an undehisced Phenakospermum guyannense capsule. The capsules are borne on a central fruiting stalk in this large (5-12 m high) herbaceous shrub. P. guyannense and the domesticated banana plant are both species in the family Musaceae. The former is strikingly reminiscent of a banana plant in form and structure, only two to three times larger in dimension than the domesticated taxon (van Roosmalen 1985). After harvesting the capsule, the infant male did not leave this nonwoody plant to seek a hard, sturdy substrate. Instead, he proceeded to strike the capsule repeatedly (10 blows) against the elongate (and extremely resilient) petiole at the base of the broad leaf blade as well as the broad leaf blade itself (Figure 5). The arm motions and body stances exhibited by the infant were indistinguishable in form and adroitness from those commonly employed by mature capuchins processing P. guyannense capsules (Figure 6). The infant, however, did not exclusively present the convex facet of the P. guyannense capsule to the substrate in his strikes. Suture edges and the two flat facets also received a minority of the strikes.”
“At that time, a big adult male was occupying a certain place of the guadua which was located nearest to a cluster of cumare. During the time he was trying to crack the fruit on the guadua, other male capuchins, who also intended to try to crack the fruit, kept away from him and either moved down two joints lower than the joint on which the male capuchin was sitting, or moved onto another guadua a little further away. A younger male among them, who had once approached the big male capuchin but had been chased back by him, could not pluck a fruit as long as the big male was trying to crack one on the guadua, so he waited 12 minutes near the tree. After the big male capuchin left, the next big male moved onto the same joint and began to crack the fruit. The younger male capuchin, who was thought to be ranked lowest, waited 15 minutes longer to get onto the same joint and crack the fruit for eating. Female capuchins, however, nonchalantly used a joint adjoining to that the largest male capuchin was using. These observations tell us three things: (1) There exists a most suitable place on the most suitable guadua for cracking the fruit of cumare. That is, the guadua should be near a cluster of the cumare, the degree of incline and the size of the guadua should be fit for use, and the manner in which a branch extends from the trunk should be suitable for sitting; (2) Such a place is definitely recognized by the group members of the capuchins; and (3) In connection with such a place, dominant relations among the members of the group especially among males, which are hardly noticeable in their daily life, are actualized.”
“During June 1997 I observed ahabituated troop of ten capuchins. One afternoon I observed two older juveniles (sexundetermined) engaged in a typical play bout. At one point they rested, and thelarger juvenile collected water from a tree cavity. This monkey cleaned debris out of the cavity and then proceeded to use one of the removed leaves as a cup from whichto collect and drink the water. The leaf was crumbled, so it likely was able to absorbwater more efficiently. The second juvenile also drank from the cavity but was notobserved to use a leaf in this manner; instead, it used the common pattern of usingits hands, feet, and/or tail. This combination of play and stopping to drink continuedfor 34 min. The first monkey retrieved water using a leaf three times during theobservation period. Each episode lasted between 2 and 5 min, and each episode wassimilar in the manner that it was performed. On two other occasions, a subadultfemale and another juvenile of the same troop were observed to use leaves to aid inretrieving water. Their pattern was similar in that they used one of the removedleaves to aid in the process. The duration of these bouts was between 1 and 5 min.Overall, this is an infrequent behavior pattern, with less than .001 events occurringper hour. Two other capuchin troops present in the wildlife sanctuary were observedperiodically; however, no individual in these troops was observed using leaves inthis manner”
“During survey work from a canoe on August 19, 1990, an adult male C. a. apella was observed feeding on oysters while seated on the roots of a red mangrove (Rhizophora mangle). Crassostrea rhizophorae is typically found fixed to the roots and lower branches of R. mangle, where it is exposed at low tide. The male capuchin was seen opening oyster shells fixed to the mangrove by hitting them rapidly and repeatedly with a hand-held object which appeared to be a piece of the oyster colony itself, from the subsequent observation that part of the colony had been extracted from the roots. Stones were absent from the mangrove and wood, the only alternative material available, would appear to be inappropriate for the activity observed. None of the remaining nine group members were observed engaging in oyster-cracking behaviour, and all moved away rapidly on perceiving the presence of the observer.”
“In Foz do Iguaçu, we observed the use of two different tools for dipping into tree trunk holes of the forest understory (approximately two meters above ground): 1) a small piece of bread provided by humans (January 7th, 14:45-14:51 h) and 2) a small branch with leaves picked up from the ground (September 6th, 16:21-16:22 h). During both events, the animal sucked the object repeatedly after multiple insertions into the cavities. During the first event, the capuchin ate the bread after dipping it and sucking from it five times. During the second event, the capuchin left the branch after drinking from it three times. It was not possible to identify the juveniles in Foz do Iguaçu, and therefore they may have been performed by the same individual or not.”
“On the other hand, when an adult male was repeating such behavior, an adult female, three juveniles, and one infant were nearby and watching him. At the moment when the adult male succeeded in cracking the fruit, the other five thronged around him, squealing and intercepting the pieces of the husk on which a little of the coco was left.”
“One large juvenile male capuchin, observed sitting on a sturdy horizontal tree branch about 7 m above the ground and occupied in penetrating the thick capsule protecting the seeds of a C. oblongifolia fruit, however, utilized a strategy to access the seeds that differed markedly from that of other troop members. This male held in his hands a baton-like branch segment, approximately 4-5 cm in diameter and 25 cm in length. Using a two-hand grip with his fingers wrapped over the superior surface of the branch, he repeatedly hit the branch against the fruit, which was resting immediately in front of him on the upper, flattened surface of the branch, which was at least 20 cm in diameter. The motion of the blow started with the branch raised in both hands to approximately shoulder height and then brought directly down on the fruit. After every hit, the fruit was carefully repositioned by the capuchin in what seemed to be a hollow or groove in the broad flat surface of the branch that prevented the fruit from rolling. The blows from the branch appeared to cause the fruit to move from this "tee" on the branch surface. After each blow, the capuchin would closely visually inspect the damage incurred by the fruit. After the extended scrutiny, the capuchin would move the fruit back to the more secure position, carefully wiggle the fruit about until solidly in place again (often a time-consuming procedure), and then deliver another blow to the fruit with the branch held in a two-handed grip. Throughout this episode his legs were bent at the knees and straddled the branch such that a foot rested on each side of the fruit. Repositioning of the fruit was usually accomplished with the feet, one foot grasping each end of the fruit. The hands were employed to reposition the fruit on at least several instances. [...]. During their observations, the capuchin struck the fruit with the branch at least 15 times. The minimum rate of blows (15 blows/10 mins.) was low, at least in part because the capuchin was deliberate and measured in its movements. [The observer] did not see the fruit capsule open or the capuchin bring the fruit to its mouth.”
“One subadult broke off a thin, 50-cm-long branch with numerous twigs bearing foliage. Using the same vigorous, downward movements as the adult male, the subadult male “struck” more than ten times at the snake, although the branch was too short to reach the snake (he was about 3 m above the snake).”
“Only once, on November 26, was it observed that, after peeling away the rind by striking the fruit against the guadua five times and then trying to peel its rind, a capuchin (thought to be under two years of age) gnawed the husk a little bit but then ignored it. Two to three-year old capuchins were observed three times feeding on the fruit of cumare, using Method I. But close examinations of the fruit left by them disclosed that they peeled the rind more than adult capuchins did.”
“Seated on top of a thick branch, the capuchin held the large, round, and heavy pyxidium (9-12 cm in diameter) in both hands, raised the fruit to about head height, and then hit the fruit forcefully (and loudly) on the branch for 4 to 8 blows in succession before stopping, carefully inspecting, and occasionally gnawing at the damaged spot, before resuming another bout of bashing the pyxidium against the branch and again scrutinizing the damage incurred.
“Sixteen capuchins who were gathered around a cumare tree included three adult males, two adult females, three adults of unknown sex, two young ones of two to four years of age and including one male, four juveniles of one to two years of age, and two infants less than one year old. Of these, all of the adult male capuchins cracked seven pieces of cumare fruit to eat. While two adult female capuchins never did crack the fruit, two of the adult capuchins whose sex was not ascertained cracked three of them. A young male capuchin of three to four years of age and a younger capuchin of two to three years of age tried to crack the fruit by peeling its rind almost completely and then striking it against the guadua. After repeating this effort 48 times and 124 times, respectively, they gave up.”
“The behavior in which the capuchin strikes the food against something with his hands in order to eat it was observed twice. One was with a snail, which a capuchin struck against a tree branch. The other was with larvae of termites or some kinds of worms in a dead branch, which a capuchin broke off the tree and smashed on the trunk to pick out the larvae.”
“The first event was recorded in Goiânia (September 7th, at 9:47 h): a male juvenile on the ground used a detached tree branch as a hammer and a buttress root as an anvil to pound an encapsulated seed of Terminalia L. (Fig. 1). One of us (E.C. Carneiro) became aware of this behavior when it was already being performed, and for this reason we did not record its duration. We were also unable to verify whether the use of this tool was successful because the animal abandoned the site carrying the seed. The second event (September 12th, 14:58-15:00 h), also in Goiânia, took place in the canopy, ten meters above ground: another male detached a small branch with leaves from a tree of an undetermined species and dipped it into a tree trunk hole (Fig. 2). The capuchin left the branch inside the hole for three seconds and then kneaded the leaves with two hands and sucked them. Subsequently, it moved one meter away and discarded the branch.”
“These bigger pebbles were sub-sequently used to pound a tree trunk or to pulverizeother embedded pebbles. In one of the quartz powderproduction events, an adult male lost his ‘‘hammer’’while licking the powder. He then tapped somenearby embedded pebbles with his fingers, and thenleft. After 2 min he came back carrying a stone (for10 m) and pounded it against a larger embeddedpebble. He removed the stone from the conglomeraterock, and then used it (after transporting it for 2 m)to strike another embedded pebble (but the ‘‘ham-mer’’ fell and the monkey left)”
“Three out of six study animals (all adult males) were observed eight times (in 8 of 72 days) (figure 1b) collecting termites (Nasutitermes sp.) from different nests in the canopy (5 –10 m above the ground). The behaviour consisted of three main steps: (i) the monkey approached the nest, reaching for and then tapping (firmly and quickly, as when capuchins tap hard surfaces) the nest exterior immediately in front of him using both palms (when in front of the nest, the body in a squatting position; semi-prehensile tail used to anchor the body on a stable horizontal branch (10 –15 cm in diameter); figure 2a,c –f ); (ii) the monkey tore off a branchlet (hereafter, stick) approximately 20 –30 cm long from the tree where the nest was located (to tear off the stick, the capuchin may temporarily adopt another body position; figure 2b), perforated the nest with it (approximately in the middle) and then inserted it into the nest (5 –10 cm deep). The monkey, always with the right hand, inserted the stick by rotating while pressing the basal portion of the stick against the nest at the opening where it was inserted. In all events, the animal continuously rotated the stick using the right-hand while perforating the nest. On two occasions, two individuals reduced the length of the stick by breaking part of its basal portion (which is free of leaves and thicker than the apices); and (iii) the monkey pulled the stick out of the nest, inspected the stick, and ate the termites attached to it (figure 2c–e). In six visits, the procedure of inserting the stick was repeated three or four times re-using the first perforation. In these subsequent repetitions, the monkeys rotated the stick in the same way. Between insertions, the monkey tapped the nest close to the perforation opening always with the palm of the left hand (the right hand holding the stick). In all cases, after finishing, sticks were discarded. Each episode of fishing for termites, from the arrival at the nest to the act of discarding the stick, lasted between 40 and 60 s (including repetitions).”
“Use of Orchid Water Storage Organ: This behaviour was recorded on 10 occasions on 5 days between August and December of 2014. Young ( n = 4) and adult ( n = 6) monkeys of both sexes used their hands to inspect the pseudobulbs of Catasetum sp. orchids (thickened stems that serve as water storage organs [Moraes and Almeida, 2004]) growing on palm (Syagrus sp.) tree trunks. They then collected the pseudobulbs, sometimes directly with their mouths ( n = 3), and sucked out the stored water. After that, the remains were discarded ( Fig. 2 c).”
“We observed monkeys using two forms of action to crack nuts, with similar frequencies. In the less-effortful form, the monkey sat or stood bipedally, held the stone in both hands, and raised and lowered the stone with arm and shoulder movements. In the more-effortful form, the monkey stood bipedally in front of the pounding stone, using its lower extremities as well as its arms and shoulders to lift the stone (see Fig. 1A). In the most extreme version of the standing form, the monkey rose quickly to a nearly vertical posture by explosively extending the joints of its lower extremities, generating high momentum, and raising the stone to shoulder height. When the monkey pounded while standing bipedally, it sometimes placed its tail in apparent compression against the upper surface of the anvil, or in tension against a lateral surfaceFpostures that may increase stability during strenuous action. In some cases, the monkey’s feet came off the ground when the animal was fully extended, as occurs also in humans who lift heavy weights while using leg extension [Bachle, 1994]. Whether the monkey stood or sat, each strike occurred as a discrete action. Strikes were punctuated by postural adjustment, and inspection and repositioning of the nut.”
“Of the aggressive incidents, 14 bouts and 21 acts occurred during aggressive displays toward me, the observer. These included seven acts in which the monkeys positioned themselves directly overhead and dropped branches, bark, and fruit that landed within about half a meter of me, one incident in which an animal positioned itself over me and urinated within centimeters of me, two incidents in which a monkey pushed 2- to 3-m tall snags (dead trees) over, aiming them in my direction--one landed within centimeters of me and the other caught on the branch of another tree--two incidents in which dropped branches (2 m x 6 cm and 2 m x 3 cm) landed precisely where I was standing and would have hit me if I had not jumped aside, and nine incidents in which small branches, bark, and leaves were dropped and actually hit me.”
“The bout of tool use during intragroup aggression occurred as the monkeys were moving into their sleeping trees one evening at the end of the dry season: An infant Cebus, about 1 year of age, approaches his mother who is in a low tree near the sleeping trees, climbs into her lap and tries to nurse. She pushes him off and he begins to scream. A juvenile male (probably an older sibling) climbs into the tree and onto the mother's back, and the two of them make threat expressions toward the infant. The juvenile reaches out and grabs the infant and pulls his tail. The infant climbs up onto a branch above the other two, directs threat expressions at them, breaks a half-meter tong branch off the tree, hits his mother with it, and drops the branch. The mother and the juvenile threaten the infant again, and the infant breaks a 20 cm long branch off the tree and strikes at his mother again, but misses her.”
“The first incident of interspecies aggression occurred in the dry season during a midmorning rest at the water hole: A coatimundi (Nasua narica) is in a small fruit tree next to the water hole. A juvenile male Cebus, who is much smaller than the coati, climbs into the tree, barks at the coati, and chases it down out of the tree. The juvenile is joined by another, and the two of them chase the coati along the ground, the juvenile picking up fallen branches and flailing them at the coati. They chase him onto a large rock and stand at its base barking at him for 5 rain and then leave.”
“The incident during interspecies play occurred late one afternoon in the middle of the dry season: A spider monkey (Ateles geoffroyi), weighing about three times as much as a cebus monkey, moves through a Bursera tree. approaches an adult female Cebus from behind and grabs her tail. The Cebus swings around and looks at the spider monkey and then moves up in the tree to a position above the spider monkey and breaks, tosses, and drops three of four branches down on the spider monkey. The spider monkey approaches the Cebus, and they wrestle playfully, grabbing and biting one another. The Cebus moves away and sits on a branch. The spider monkey follows, sits next to the Cebus, and presents its underarm for grooming. The Cebus ignores the invitation.”
“The only tool-use act that occurred in a feeding context was late one afternoon at the beginning of the dry season. The monkey, a subadult male Cebus, was foraging for insects in a low tree and had broken a small dead branch off the tree and examined it, presumably for insects: He slowly walks down a branch with the stick in his hand, evidently looking for insects as he walks along. He stops and looks into a small hole and pokes the stick into it, pulls it out (I do not see anything on it), and then puts it in his mouth and continues walking down the branch.”
“The second incident occurred in the late afternoon at the end of the dry season: A subadult male Cebus is sitting on the ground extracting seeds from a Luhea pod. Two collared peccaries (Tayassu tojacu) approach. The monkey dashes up to them, running along the ground. Still holding his Luhea pod in one hand, he picks up a fallen branch in the other and throws it horizontally at the peccaries. Two other monkeys join him, and another peccary joins the first two. The three monkeys make threat expressions, vocalizations, and gestures at the three peccaries, but the peccaries pay little attention and walk right through the group, passing within about a meter of the three monkeys.”
“The tool-use act performed during intragroup play occurred early one afternoon at the beginning of the dry season. Two Cebus youngsters estimated to be about 1 and 2 years were playing. The older of the two picked a dead branch off the tree they were in and poked the younger animal with it.”
"“On 12 May 1988 a regular booming sound was heard a few hundred meters to the south of the observer (J.M.F.). The sound was similar to a person chopping a tree with an ax but lacked the metallic ping. The sound persisted for 5-10 sec. Approximately 2 min later a second bout of the booming was heard. Upon searching for the source of the sound it became evident that it was emanating from a large (ca. 170 cm diam.) Autrunella congolensis tree 200 m from where the sound was initially heard. Upon approaching the tree a large female chimpanzee was observed ca. 20 m up the trunk in the crotch of a primary branch. The observer’s presence was not noticed by the chimpanzee that was manipulating and consuming contents from a large melipone (Trigona (Hypotrigona) gribodoi Mag.) [ex Bahuchet, 1985] hive attached to a very large primary branch of the tree. These hives, constructed with copious amounts of propolis, are often attached high on the main trunk or primary branches of several of the largest emergent species of trees in the study area (e.g., Entandrophragma utile, Ceiba pentandra, Autranella congolensis, Milicia excelsa). The chimpanzee was standing bipedally, grasping the tree with its right hand and manipulating and eating with its left hand. After some time it stepped back on the branch and picked up a large dead piece of branch 30-40 cm long and 10 cm diameter which was lying in the crotch of the large primary branch. It then proceeded, with both hands and the right hand only, to use the wood to batter the bee hive. The chimpanzee grasped the piece of wood in the middle and used the end for a pounding surface. After hitting the hive ca. 10 times, the pounding tool was placed back in the crotch of the branch and the same position was taken to extract and consume honey and probably bee larvae. The chimpanzee was observed inserting the left index finger into the hive and then into its mouth several times. It repeated this cycle several more times, each time beating the hive 6-10 times, intermittently swatting at bees around its eyes with a cusped fist and feeding. After several minutes the chimpanzee spotted the observer, issued distress screams and moved higher into the tree. At this point the observation was terminated. It was not established if the chimpanzee transported the dead branch up to the perch or if it was found in the tree.”
(see document)
9:07 Termite nest puncturing subroutineThe chimpanzee pushes a puncturing stick into the ground. After reaching the desired depth, the tool is removed by pulling upwards with both hands while the chimpanzee stands bipedally. The end of the tool or insertion point is then often smelled or visually inspected. (Humans can detect if a termite nest has been punctured by the smell of termite pheromones that are released when a nest is attacked.) If a nest has not been breached, the chimpanzee continues inserting the puncturing stick in nearby locations.
9:15 Termite Fishing subroutine. This involves brush straightening, insertion and extraction of the tool, and gathering the termites from the tool. With the brush-tip fishing probe, it is often necessary to straighten or arrange the brush fibers before each insertion into the tunnel. The probe is inserted into the termite nest, and then extracted with termites clinging to the brush fibers. Termites are gathered into the chimpanzee's mouth using either the pull-through or direct-mouthing technique.
9:27 Using a fishing probe to clear a nest tunnelAfter failing to insert the probe, the chimpanzee reverses the orientation of a brush-tip tool and uses the blunt end to clear loosened soil from the entrance of the fishing hole. The probe is then reoriented for fishing and the brush straightener before insertion.
A short while later, an adult female with two fabricated sticks approached the nest entrance and let her juvenile offspring lick the end of the first stick, while she used the second one to extract more honey.
Among wild chimpanzees, I have not observed exactly this type of poking and prodding, but sticks are used to smell unfamiliar objects. When a dead python was placed at the feeding area one 8-year-old female, who had been staring at it for some time, first sniffed the end of a long palm frond on which the snake had lain, and then pushed it, hand over hand, until its tip touched the python’s head (which was bloody). She then withdrew the implement and sniffed the end intently.
At 09.01 hrs, the adolescent male stopped eating, paused a moment, then twisted and pulled off a small branch at his side. He placed it in front of him on the prickly branch and carefully stepped onto it, gripping the tool between his greater and lesser toes, first with one, then the other foot and then he squatted down. He then leaned forward and pulled off a bunch of fruits and ate until at 09.05hrs, when he climbed higher in the canopy, letting the stepping-stick fall.
At 09.24 hrs, Magic J. broke off a small branch, approximately 30 cm long, with flowers and buds on the tip, and carried it in his left hand for about 3 m before he stopped, placed the tool under his left foot, gripping it between his greater and lesser toes, pulled down another branch from above with clusters of flowers and ate.
At 09.42 hrs, McGrew started to walk down the branch where he had been eating and with his right hand bent down a short, young branch and walked, first on the knuckles of his right hand, then with his right foot across it. As he made another step forward, he again bent down a young, smooth branch in front of him and gripping it with both feet, squatted and ate.
At 10:47 in the morning, EG and two assistants heard a series of pounding sound in the same study area. A total of fifteen pounding bouts, each consisting of 1–10 beats, were heard until we reached the site, where an adult male chimpanzee sat on the branch of Aucoumea klaineana (Burseraceae) tree. Unfortunately the chimpanzee detected our approach and descended from the tree before we could observe his tool-using behavior in detail. The tree was about 30 m and the beehive of Meliponula sp. was on a large branch at 25 m in height. Two sticks were left on the ground under the tree: One was 117 cm in length and 48 mm in diameter, another was 104 cm in length and 1.3 mm in diameter). The chimpanzees probably used the first stick to pound and cracked the entrance of beehive as observed in the previous day, because an end of the first stick was battered and brush shaped. It was dried out but smelled of honey, and removed from a branch of a Diospyros sp. tree neighboring (about 5 m away) to the tree of the beehive. The second stick seemed to be used as a collector, as it was inserted into the hole to extract honey. It remained still sticking out of the cavity. It was fresh and made from a vine (species unknown) nearby”
At 12.23 hrs, I saw the adult male break off a small branch, sit on it and continue eating. He continued to use the seat-stick for 9 more minutes before he moved off and (presumably), dropped the tool.”
At 15.29 hrs an adolescent male stopped eating, stood quadrupedally and started towards another branch. As he stepped forward, he paused and broke off a small, smooth, brittle branch and placed it Infront of him on the prickly branch. He carefully stepped on the branch with his left foot, gripping it between his greater and lesser toes, leaned forward and pulled another branch towards him. Holding the second branch in his mouth, with one hand he broke off a small twig from it, which he then placed under and gripped with his right foot in the same way he had the other tool. He adjusted the stepping-stick held by his left foot and squatted down, reached up and pulled off a bunch of fruits and ate. At 15.32 hrs, he stood up and took one of the step-ping-sticks from under one foot and placed it slightly further up the branch and stepped forward onto it, which enabled him to reach forward and pull off a fruit. Then he took the same stepping-stick from under his foot again, placed it back beside the other, and holding one tool in each foot, squatted down and ate. Again at 15.34 hrs, he stood bipedally, lifted one foot, still gripping the tool between his toes, reached for another bunch of fruits, then put his foot down and squatted again to eat. At 15.37 hrs, he stood again bipedally and stepped forward with one foot still gripping the tool onto another branch, leaned forward, picked a bunch of fruits, and stepped back to where he had been, still gripping the tool and ate. Finally at 15.42 hrs he dropped both tools and briefly entered a neighboring tree before returning to eat in the Ceiba pentandra tree.
A 2-year-old infant used leaves in the adult manner, but twice chose very tiny ones.
A 2-year-old infant used leaves in the adult manner, but twice chose very tiny ones. A three and a half-year-old infant, however, after first dipping his hand into the water then poked in a piece of dry grass, using movements similar to those observed during termite feeding. Each time he put it to his mouth, he chewed the end: eventually, therefore, the stem was a tiny crumpled mass-a minute “sponge” (Fig. 18). Soon he abandoned this and poked in, again with termiting movements, a long narrow dead leaf. When he withdrew this, he immediately crumpled it in his mouth to make a sponge. On subsequent occasions he once used a similar leaf, but abandoned it after 2 minutes; once he used a leaf mass left by another individual; and once the back of his fingers again. Three other infants were observed using sponges in apparently playful contexts: the same may be true for the infant just described
Example 1. June 22, 1975. 1019: An adolescent male (MS) shakes a branch with one hand in a tree, while facing to a young adult female (WH) in estrus below. MS violently shakes the branch with one foot, while standing bipedally. He picks a leaf which he rips to pieces by repetition of horizontal sweeping movements of one hand while holding the leaf between his teeth, causing a great crunching sound. WH approaches MS, who then slaps the tree trunk with one hand and moves toward the edge of a branch. WH follows suit. 1021: When MS stamps the branch with one foot, WH comes close to him and adopts the presentation posture. MS copulates with her. B. Male signal to estrous female, not accompanied by other courtship gestures
Example 10. August 22, 1977. 1128: Before provisioning, an assistant shows a long stick of sugar cane to 2*5-year old male (KB). KB picks a large dead leaf from the ground and begins to bite at it with a dry, crunching sound. He stands 50 cm in front of the assistant. KB then picks up a dead branch, which he clips off with his incisors.
Example 11. September 9, 1977. 1346 l/2 : The observer is sitting on a stick of sugar cane (to prevent it from being stolen by the chimpanzees). A 2.5-year old male (KB) uses an arboreal pathway and comes to the tree under which the observer sits. He shakes a vine with one foot and then bites off a large leaf.
Example 12. April 10, 1976. 1306: An adolescent female (MD) cannot obtain sugar cane, although all the others do. MD takes an arboreal pathway and comes close to the observer. When she finally arrives in the tree above the observer, she picks a leaf, bites at it, and lets pieces of the leaf-blade fall.
Example 13. July 20, 1977. 1139: Only one chimpanzee (past-prime adult female, WT) is met in the bush. After the observer supplies her with several pieces of sugar cane, we cease provisioning. 1147: WT sitting in the thicket, shows a nodding display with a half-open mouth to the observer (i.e. the sugar-cane holder). 1155: She grunts (Goo). 1210: She shakes a branch, emitting hooting sound (Hoo). 1214: She nods, while emitting hooting sound (Hoo). 1220: She grunts (Woo) and hoots (Hoo). 1238: WT picks off a large, dry, green leaf with her left hand and bites at it with a dry crunching sound, letting the pieces fall. 1239: She scratches herself. 1241: She emerges partly from the bush (showing not only her face, but also her shoulders, abdomen, arms and legs), seemingly to attract more attention from the observer, then retreats again. 1249: She again shows herself. 1252: She grooms herself. 1301: She shakes branches. 1302: She shakes branches.
Example 14. November 26, 1975. 1455: One-year old male (KB) plucked a leaf, bit it off and whimpered after his- mother moved away from him to be groomed by another adult female. There was another infant male, I-5-year old LK, nearby, whose mother also was being engaged in social grooming. He approached to KB, probably to play with him. But, an adult male (KS) lying on the ground reached out his hand and began to play with KB, by poking him at the belly with his finger tips. Then LK began to bite off a leaf.
Example 2. May 11, 1976. 0959: 4-year-old male (LL) bites off stiff leaves. An estrous female (GW) on the ground looks up at him and begins to ascend the tree. LL moves toward the edge of a branch while holding the leaf piece between his teeth. GW follows suit and adopts the presentation posture. LL copulates with her, making 30 thrusting movements of the pelvis.
Example 3. May 12, 1976: 1210: MS, in the tree, plucks plenty of leaves and begins to bite at them. When he makes a crunching sound for the third time, GW who has been lying 5 m under MS, looks up at him, hastily ascends the tree and assumes the presentation posture. MS copulates with her, making 10 thrusting movements. then returns to the place where she was lying and lies there while showing her buttocks to MS.
Example 4. May 7, 1976. 1132: MS sits in a tall tree. He picks a leaf and begins to bite at it. GW hastily comes close to him from the neighbouring tree. MS moves to the edge of a branch. GW bends a branch and lies on it in a fork of the tree. 1134: MS again plucks a leaf, holds it between his teeth, returns to the place 2 m away from her and begins to bite at it. 1135 : MS bites at the leaf again. 1135 l/2 : MS comes closer to GW and then goes to the edge of the branch. GW follows suit. MS copulates with her. After the copulation, GW crouches in the fork of the tree.
Example 5. May 8, 1976. 1259: MS holds a leaf with the right-hand and crunches the leaf-blade until only the mid-rib remains. MS briefly grooms an estrous female (WS). 1301: MS picks off another leaf and bites it off. WS grooms MS. He moves to a neighbouring tree, picks a stiff leaf and bites at it. He breaks off a twig and bites off the Ieaves one after another. WS comes close to him and assumes the presentation posture. 1302 l/2: MS copulates with WS, making a long series of thrusts. After the copulation, MS grooms WS. C. Estrous female signal to male, as sexual solicitation
Example 6. May 7, 1976. 1222 : GW, in estrus, sits in a tree. She holds a twig with 5 to 6 leaves in her right hand and begins to bite at them. MS immediately approaches GW, who also comes close to MS. MS makes a U-turn. GW follows suit. They move to the neighbouring tree. 1223: MS copulates with GW.
Example 7. May 8, 1976. 1440: A past-prime female (WW) from K-Group is in estrus. She is observed in a midst of a large subgroup of M-Group. She emerges from the bush and approaches an adolescent male (DE) of M-Group. 1444: WW picks off a leaf of a shrub and bites at it with a great crunching sound. 1448: DE sits with an erect penis but does not move. Instead, another adolescent male (LJ) comes close to her. 1451: LJ copulates with WW. D. Male signal to estrous female, in consort relationship
Example 8. February 29, 1976. 13 19 : The top-tanking male (KS) ascends a high tree. WL, in estrus, pant-screams. KS moves to the neighbouring tree and brandishes a branch, while he picks a large leaf, bites at it with his teeth with a great ripping sound, and lets it fall. He twice repeats the ripping sequences. WL, in the tree, slightly approaches KS. 1324: KS moves to another tree and bites off the leaf. 1326: KS descends the tree. WL follows suit. KS moves westward and WL follows him.
Example 9. September 9, 1977. 1503: An adult male (KM) copulates with a young estrous female (GM). 1518: KM sits in a tree 2 m above the ground. He shakes a vine, while looking up at GM, who sits very high in the tree. 1519: KM descends the tree. 152 1: KM drinks from a stream. KM picks a big leaf of a shrub and begins to bite at it with a great crunching sound. 1523: with an erect penis, he has clipped four leaves. 1528: KM lies supine on a rock, while looking at GM. 1531: GM touches her perineum with her fingers and sniff them. 1535 : KM begins to shake shrubs. 1536 : GM begins to descend the tree. 1539: KM begins to walk. GM follows him.
In addition to the above use of leaves, a female chimpanzee once used a twig apparently to pick her teeth, after first using her finger nail
In another instance, on the 23rd of July 2005, C.B. and an assistant were attracted to a site by a loud pounding sound, at which two adult males were seen to use tools to extract honey for 13 minutes from a big fallen branch. (...) The second male used a ready-made tool lying on the ground.
In another instance, on the 23rd of July 2005, C.B. and an assistant were attracted to a site by a loud pounding sound, at which two adult males were seen to use tools to extract honey for 13 minutes from a big fallen branch. The first chimpanzee used a large broken shrub with leaves and branches still intact, and tried to push it into the hole. He then broke the shrub, rejected the end with the leaves, and shoved the newly modified tool into the hole and performed sweeping semi-circular motions before removing it and putting it into his mouth. He then pulled the tool through his mouth to remove the honey, and reinserted it into the hole. The second male used a ready-made tool lying on the ground.
In the second case, a juvenile female also fished briefly from a hole in a fallen tree trunk, using a 20-cm herbaceous stem from which she first stripped the leaves. She apparently did not obtain any food. Tool use for hygiene was much more”
Katie is a wild-born, 1 1-year-old, far- western chimpanzee; she is an avid collector of both types of honey. She is a member of a free-ranging community numbering 1 1 individuals living on a 68-ha island in the Gam- bia River. This is one of three islands in The Gambia that are occupied by chimpanzees rehabilitated from captivity [7]. Except for being given supplementary food to enable monitoring, the apes lead self-sufficient lives with little contact with humans, although they can be observed in the same way as habituated wild chimpanzees. One day, while foraging in woodland, another chimpanzee found a stingless bees’ nest in a dead stump of a tree-bough. She picked away the waxy, trumpet-shaped structure at the entrance to a nest, but was then displaced at the site by Katie. Katie first broke off a green branch and made it into a ‘fishing’ probe, that is, a long, thin, flexible ‘dip stick’ about 35 cm long and 8 mm thick. This was inserted several times into the nest entrance, but collected no honey. (Apparently the reservoir of honey was too far down inside the stump or the passage-way was too winding to allow the end of the probe to reach the goal.) She then abandoned the tool and scrutin- ised the stump from many angles for about 3 min. In doing so, Katie found another po- tential entry to the nest through its outer layer of batumen. (Batumen is a mixture of wax, resin, mud, or vegetable matter made by the bees to seal fissures in the nest wall; it hardens to the consistency of cement [5].) After briefly scraping at the batumen with her fingernail, the chimpanzee tried to break off the stump. Neither pulling at the stump nor kicking at it with her heel had any effect. Katie then broke off a dead branch which produced a stout tool with a sharp end; it was about 35—40 cm long and 20 mm thick (fig. 1 a). This ‘chisel’ was held in an active palm (‘power’) grip and jabbed repeatedly with an overarm motion. The force of the blows caused the batumen to begin to crumble, and she abandoned the tool after l —2 min. Then the chimpanzee detached a second tool which was shorter and thinner (about 25 cm long and 15 mm in diameter). and sharper-pointed (fig. lb). She used this other chisel in both active and passive palm grips to widen the excavated hole by removing more batumen over the next 4—5 min. Sheinspected the hole, inserted her forefinger to its full length, and then withdrew it to sniff it. Katie then picked a green branch about 1 cm in diameter and trimmed it to about 30 cm length to make a third tool. This ‘bod- kin’ was inserted and first jabbed and then pushed with maximum force, though this could only be done with one hand as the other hand was needed for suspensory sup- port (fig. 1 c). She gripped the tool with her teeth as well as one hand, thus enlisting the power of neck muscles too, and this punc- tured the seal of the nest. After examining the stick, licking its end, and trying one trial insertion, it too was abandoned. Finally, Katie made a fourth tool, another fishing probe, from a green vine. This dip- stickmeasured about 75—80 cm by 8 mm. It and other similar probes were then used in a modified pencil (‘precision’) grip for about 10 min to extract copious amounts of drip- ping honey(fig. 1 d). Two other chimpanzees waited and watched Katie before succeeding her at the hole, while another two sat below the tree, collecting and sucking on the dis- carded tools.
Loïc Mackaga made a detailed observation of chimpanzee tool use at an arboreal honeybee nest in October 2008. (...) Two adult females, up to 5 m away from the hive, made tools and used them to enlarge the nest and remove pieces of honeycomb from its wall. Once successful, they let the tool fall down and removed the comb with their hands (Fig. 1d and e).
Loïc Mackaga made a detailed observation of chimpanzee tool use at an arboreal honeybee nest in October 2008. An adult male chimpanzee was observed to first break the entrance of the nest with a large pounder and then remove honeycombs with his hand. Two adult females, up to 5 m away from the hive, made tools and used them to enlarge the nest and remove pieces of honeycomb from its wall. Once successful, they let the tool fall down and removed the comb with their hands (Fig. 1d and e).
Observation 2 (06/08/2017, 13:47:59) Cambeque (secondary open forest). Juvenile individual (sex undetermined) approaches an abandoned BM hive with a small green stem, with some attached leaves, in his/her mouth. With the right hand, the individual removes the leaves and inserts the proximal tool end into the hive’s narrow entrance, moves it around in a circular motion, takes it out, smells the tool end, inserts it again now with greater force, pushes it as far as it will go, pulls it out, looks at it and leaves. See video S1.
Observation 3 (18/11/2017, 14:23:14) Madina (mangrove). Adolescent female approaches tree with MM hive, climbs up, breaks a twig with attached leaves, holds it in her mouth and climbs further until she is out of view (the camera trap has been knocked out of position and its view is no longer centred on the hive). The distal end of the tool (with leaves) is seen falling towards the ground.
Observation 4 (04/12/2017, 12:12:16) Madina (mangrove). Adult female with an infant climbs up tree, sits down, breaks a branch with her right hand, and climbs up carrying it towards the hive, out of view. Leaves are seen falling.
Observation 5 (04/04/2018, 10:01:32) Madina (mangrove). Young adult female is seen sitting next to hive, she stands up, breaks off a twig with no attachments with her right hand, quickly inserts the proximal end into the hive with back-and-forth and circular motions, takes the stick out, puts proximal end into her mouth and leaves.
Observation 6 (08/04/2018, 07:07:40) Madina (mangrove). Adult female is seen dangling from tree branches (approximately 4m from the ground), breaks twig with right hand while holding herself with left, inserts proximal end into hive entrance, brings it to mouth, discards tool, rapidly descends and runs away.
Observation 7 (18/06/2018, 16:44:42) Madina (mangrove). Juvenile female is seen in front of hive inserting a small stick into hive’s entrance, puts the whole stick in her mouth, breaks a larger twig with attached leaves, descends the tree carrying larger twig in her mouth. A second adolescent female approaches the same location carrying a broken twig with attached leaves, inserts the proximal end into the hive’s entrance with considerable force, pulls it out, inspects it and discards it.
On August 14, 1994, [...] a large female chimpanzee was observed ca 25 m in the crotch of a primary branch of the tree trunk. The observers' presence was not noticed by the chimpanzee who was manipulating a large dead piece of branch 70 cm long and 4 cm diameter. The chimpanzee grasped the piece of wood in the middle and used the end to pound the bee hive. Having started an indentation on the hive, she turned the wooden-pounding stick and inserted its opposite sharp-pointed end into the hole. This bodkin allowed her to puncture the nest wall and to alternate levering and pushing motions of the tool. She reached into the hive with her hand. The female left the piece of wood and climbed to the crown of the tree, 6 m above the hive, and broke off a small branch which she snapped in half, stripped them of leaves, and carried it in her mouth. She returned to the hive and pushed the new stick ca 60 cm long into the hole. After 2 min she changed her position sitting on a branch placed over the hive and from above she carefully inserted the longer and flexible stick using it to dip out the dripping honey.
On January 20, 1993, at 13.31 hrs, I found an adult female, Namaska, and her juvenile son, Hess, eating Ceiba pentandra fruits. It was not until 15.29 hrs that I saw her eating while squatting on a small stick, gripped between the greater and lesser toes of her right foot. I did not see her break off the tool, but she had not used it for longer than about a minute. She then stood quadrupedally and moved a couple of steps to the side with the stepping-stick still held in her foot to avoid the thorns, and reached forward to pluck three pods, then dropped the stepping-stick and climbed down to the main trunk of the tree.
On January 7, 1995, a juvenile chimpanzee was recorded pulling out a stick from a termite mound matrix and after that repeatedly pushing the stick into the hole of the mound. [...]. The individual turned the stick and inserted its opposite brush shaped end, into the hole several times to fish for termites. When the chimpanzee became aware of the observers' presence, tools were left laying on the ground nearby or in the small holes of the termite mounds. they had broken the sticks off three small trees growing around the termite mound.
On May 7, 1995, two chimpanzees, one adult female and one adult male, were observed ca 20 m up in a Ficus tree. [...]. Upon arrival the adult female was holding a piece of wood 40-50 cm long and ca 7 cm diameter in her right hand. She pounded the wood against the bee hive several times. Afterwards the chimpanzee turned the tool and introduced its bodkin end into the hole. She alternated strong levering and pushing motions of the bodkin tool. She left the tool on the branch and moved 15 m away to break off a small branch which she stripped of leaves and carried it in her mouth. She returned to sit behind the bee hive and spent 10 min extracting honey with the stick.
On another occasion a juvenile, when he was prevented by his mother from touching his newborn sibling, repeatedly touched her gently with a stick and then sniffed the end
Once a juvenile wiped sticky banana from the head of her infant sibling with leaves.
One adult male was observed to first remove the bark of a Garcinia sp. branch with its teeth and then put one end of the stick in its mouth and chew on it, as if to fray it before using it to extract honey.
One male chimpanzee at the Gombe National Park appeared to make deliberate use of abnormal objects to better his charging displays: this, in turn, probably led to his becoming the dominant male of the group. In 1964 he held a very low social status. In December that year he began to use empty 4-gallon parafin cans during his charging displays. Initially he used one can only, hitting it ahead of him with alternate hands o r occasionally kicking it as he ran. After a while he was able to keep three cans on the move at once without noticeably diminishing his speed. T h e effect of such performances on his conspecifics was dramatic; the noise of the cans was tremendous and, as he approached, the other chimpanzees hurried out of his way, including those who held a much higher status. Often he repeated the display three o r four times, running straight toward one or more of the other chimpanzees present. When he finally stopeed, the others usually approached and directed submissive gestures toward him. After 4 months we removed all cans, but by then he had acquired the number one position-which he still holds five years later. That his use of these cans was deliberate is suggested by the fact that, once the pattern was established, he would often walk calmly to the tent and select his cans. He dragged these quietly to a place from where he could, for instance, watch a group of conspecifics resting and then sat quite still for 5 minutes. Then he gradually started to rock, his hair slowly erected, he began a series of calls and then finally charged straight toward the peaceful group.
The most frequently observed tool-using behavior in the Gombe Stream area is the use of stems and small twigs during termite (Macrotermes bellicosus) feeding. After opening up a passage in a termite mound, a chimpanzee picks a grass stem or small twig and pushes it carefully down the hole. After a slight pause he withdraws the tool and picks off with his lips and teeth the insects clinging to it. The tool is held between the thumb and the side of the index finger (Fig. 15) with a precision grip (Napier, 1960).
Two years later, on January 4, 2005, S. Y. found JJ (7 years 2 months old at the time) fishing for carpenter ants nesting in a hollow in the trunk of a tree (Pseudospondias microcarpa) 8 m above the ground (Fig. 1B). His ant-fishing lasted approxi- mately 7 min, and three bouts for 3 min 57 sec were video-recorded. JJ succeeded in one of the three bouts in eating approximately three ants. S. Y. witnessed an additional successful bout before filming the behavior. During this observation, JJ was never bitten by the ants and held the wands between his thumb and the side of his index finger of his left hand. The tools used by JJ at age 7 for ant-fishing in the tree were significantly shorter than those he used for ant-fishing at age 5 (Table I). At age 5, JJ used wands of similar length for both ant-fishing in the tree and ant-dipping on the ground. In contrast, the wands used for ant-fishing at age 7 were significantly shorter than those he had used for ant-dipping during the same period. The wands used for antfishing at age 7 were also significantly shorter compared with the community average wand length of 50 cm recorded for ant-dipping [53.7 cm, Humle and Matsuzawa, 2002; 46.7 cm, Sugiyama, 1995]. The detailed analysis of the video-recorded ant-fishing at age 7 shows that JJ had shortened at least one of the three wands during us
Use of stick to knock food object to the ground. This occurred once at the Gombe Stream when a mature male was afraid to take a banana held out to him by hand. After staring at the fruit he shook a clump of grasses in mild threat. He then shook them more violently and one of the stems touched the banana. He stopped shaking, let go of the grasses, plucked a thin plant from the ground, dropped it immediately and broke off a thicker stick. He then hit the banana to the ground, picked it u p and ate it. When a second banana was held out he used the tool immediately. This observation is of interest since it was the only time when it was possible to observe what was probably an original solution to a completely new problem involving tool use in the wild.
[...] At 17.01 hrs, I found Namaska and Hess still eating in the same Ceiba pentandra tree. At 17.48 hrs, Namaska started climbing down from the top of the canopy. She paused and broke off a fruit and held it in her mouth. As she started to climb up another branch, she broke off a small branch and, first holding and using it with her hand, pulled herself up before she stepped on to the tool with one foot, and then let the tool fall as she climbed to a wide horizontal branch where she sat and ate. Namaska and Hess remained eating in the same tree until at 18.10 hrs, then both traveled further north into the valley
a moment later an adult male chimp came ambling around a bend, bearing an armful of dried palm nuts, supporting himself on his right knuckles. He reached the rock, sat down clumsily and proceeded to select a nut. He then picked up a chunk of rock and pounded the nut which had been placed on the flat surfaced rock.
an infant briefly used a twig to pick his nose.
In a similar manner the chimpanzees at the Gombe Stream began to use sticks to try to prize open the lids of boxes containing bananas (Fig. 14). Usually the chimpanzee, after breaking off a suitable stick, stripped off the leaves and often bit splinters off one end so that they formed a chisel-shaped edge.
On September 17, Nsaba, another adult male, was observed closely watching Kalunde engage in this behaviour.”
Once an infant picked up a hard clod of earth to which was attached a few long dry grasses. Holding the ends of the grasses in one hand he swung the clod beating his playmate with it time and again
one female constantly wiped her genital area with leaves during her menstrual periods
when a chimpanzee had diarrhea it often wiped itself clean with a very large handful of leaves.
– August 14, 2002: Adult male HA and adolescent GTZ watched adult male RU as he used a leaf sponge to extract water from a hole at the base of a tree buttress. Both approached the tree after RU left, looked at the hole, and inserted their fingers into it, but neither used the discarded leaf sponge or made another.
– August 15, 2004: Adult female CAR used a leaf sponge to extract water from a hole at the base of a tree buttress. Her juvenile daughter stood next to her and watched her closely, then picked up her mother’s discarded tool when CAR left and inserted it into the same hole. She repeated this 4 times and obtained a small amount of water.
– July 16, 2002: Four adult males found a beehive in a hole in a fallen tree trunk. A high-ranking male, EL, inserted his hands into the hole and extracted a large mass of honeycomb. α-male BT also extracted some honey with his hands, but EL apparently had obtained most within easy reach. When BT finished eating his honey, he inserted a stick about 30 cm long and 1.5 cm in diameter into the hole. He thrust it back and forth and from side to side vigorously, then withdrew it and ate a small amount of honey that adhered to it. He repeated this several times while EL ate his honeycomb, then discarded the tool and picked up a second stick of similar dimensions. He briefly chewed on the end of the stick, then inserted it into the hole and vigorously thrust and rotated it. EL finished most of his honey while BT was using his second tool, at which point he sat and watched BT. When BT moved aside slightly to eat some honeycomb that EL had dropped, EL picked up BT’s first tool, inserted it into the hole, and extracted a small amount of honey. He repeated this several times and also used BT’s second tool once before leaving the trunk. BT then made another tool from a third stick and resumed his efforts to extract honey. BS, a young, high-ranking adult male, and adolescent male BRA watched him closely. BT discarded his third tool and left the tree trunk 12 min after the honey extraction started. BS picked up BT’s third tool, inspected it, and sniffed the working end, but did not insert the tool into the hole in the tree. He then left the site. BRA left the site without inspecting any of the tools.
‘The termites bit on to tools pushed into these holes: the chimpanzees then withdrew the tools and picked off the insects with their lips”
“ After having located a suitable digging trench, the chimpanzee raked away the surface debris with one hand. The chimpanzee then pointed the end of the digging stick at the location that had been cleared of leaves and began to push the stick tool into the ground with both hands grasping the midsection of the tool. They often used one foot to grasp the base of the tool while their body weight was shifted over the tool to press it further into the ground. The chimpanzee then removed the tool and smelled the tip of the stick, which may have pierced a termite-nest cavity. If a termite nest was hit by the puncturing stick, then the chimpanzee began to fish by inserting a fishing probe into the canal that was created by the puncturing stick. If not, the puncturing process was repeated.”
“ Some individuals inspected several clumps of grass, etc., before selecting their tools, and sometimes picked several to carry back to the termite heap and then used them one at a time. Other individuals used more or less anything within reach, including tools left by others. Sometimes tools were carefully prepared: leaves were stripped from stems or twigs with the hand or lips, and long strips were sometimes pulled from a piece of grass which was too wide. No chimpanzee was seen to move farther than ten yards from the site to select a new tool, but individuals were observed to pick a tool for use on a heap which was out of sight and as far as one hundred yards away. Onc male twice carried a tool for more than half a mile while inspecting a series of”
“ The animal may choose to open the nuts directly in the tree, using a horizontal branch as an anvil. In this case, it must always anticipate its action by looking for a hammer before climbing into the tree. While carrying the hammer in a hand or a foot, the chimpanzee picks the nuts and stores them in its mouth and a hand. It then chooses a branch as an anvil for pounding the nuts. To us, the subsequent behaviour in the tree resembles the performance of an equilibrist. The animal cracks a nut with one or both hands while holding the rest in the mouth and one foot. To eat the nut, the mouth has to be freed by transferring the nuts to one hand while the hammer is held with one foot or left to balance on the branch. To continue the cracking, the hand has to be freed again by putting the nuts back to the mouth, and so on. Often, to prevent the pounded nut from falling from the anvil, the animal retains it on the branch with the thumb and the forefinger of one hand between hits. To collect more nuts, the hammer is carried or left balanced on the anvil. Obviously, cracking nuts in the tree implies better co-ordination of more movements than doing so on the ground. On the other hand, nuts can be reached within arm's-length or collected at a few meters from the anvil. This is an obvious advantage compared to the chimpanzee who has to climb at least 15 In up a tree and down again for each load of nuts to open them on the ground. “
“ likely that any nonpoisonous leaves would be used. From one to eight or more leaves (depending on their size) were stripped by hand or with the lips from a nearby twig and then chewed briefly so that the surface was crumpled and the water carrying capacity thereby increased. The leaf-mass, held between the index and second fingers, was then pushed into the bowl, withdrawn, and the water sucked out of it. The process was repeated until the bowl was empty or until the chimpanzee was no longer interested. “
“- July 13, 2000: High-ranking adult male MW used a leaf sponge to extract water from a hole in a tree buttress. Adolescent male DX watched from several meters away. When MW discarded his sponge after 3 min and left, DX retrieved it and sponged water from the same hole for 2 min. Adolescent female RUS also watched MW use his tool, but left before he finished.
“A chimpanzee who crouched in front of the platform stone chose a dry palm-seed, placed it in the cavity of the platform stone, gripped the handle side of the pebble tool, lifted it up to a height of 5-20 cm, and then struck the palm-seed. It took the chimpanzees 2.84 strikes on average (n = 18 crackings) to crack a palm-seed, although it took the unexperienced author 2.5 strikings on average. When a palm-seed was broken, the chimpanzee removed the white ovule with his fingers and ate it in about 1 min. Then, he attempted to crack another palm-seed. After the chimpanzees had left the authors examined the broken shells and found little remaining ovule in them. However, in the author's broken shells there was sometimes much remaining ovule which could not be separated from the shell.”
“A male stripped a handful of leaves to wipe mud from her foot.
“After a dead branch had fallen down, termites sometimes began to make a nest in the hollow of the tree. The chimpanzees would then take a small twig of 5-15 cm in length, remove the side branches and leaves, and so make a small stick. Next, they would beat and pound the bottom of the hole several times. On pulling the stick out a few termites would be attached to it, mostly broken and adherent. The chimpanzees would lick them off and again try to pound the bottom of the hollow. Two adult males (Tua, Aiwa) attempted this for 30 rain each on a Canarium schweinfurthii tree but succeeded in retrieving only a few termites. For obtaining resin the chimpanzees took a somewhat longer twig than that used for termite digging, that is, 10-20 cm in length. Removing the side branches and leaves with their teeth quickly, they repeatedly pounded and mixed by stirring the bottom of the hollow of a tree (always Carapaprocera). On pulling the stick up, a brown-colored resin was seen to be conglutinated stickily on it. The chimpanzees licked this off and repeated the same procedure for more than a quarter of an hour. This kind of activity was observed only in adolescents (Non, Kure) and juveniles (Fino, Vu, Jima)”
“After handling bananas which had been smeared with honey in a feeding experiment, two individuals used leaves to wipe themselves: an infant pulled leaves towards her and rubbed her sticky lips with them, and an adolescent stripped off a handful of leaves with which to rub her other hand.”
“After taking a stem from the herb stand, the chimpanzee removed the leaf from the distal end of the stem with his/her mouth. An end of the tool was then pulled horizontally through partially clenched teeth several times to fray the end of the herb into a brush tip. There was a specific technique for inserting the brush-tip tool into the termite nestdthe brush tip was wetted with saliva and then quickly pulled through the hands or mouth to straighten the fibers. This brush straightening was performed almost every time that the tool was inserted into the nest. The probe was withdrawn from the nest in one swift motion, sometimes with the tool stalk resting on the opposite arm for support. Termites were gathered into the chimpanzee’s mouth using either the pull-through or direct-mouthing technique.”
“An adolescent picked leaves to wipe off drops of urine which had splashed on to him from a juvenile sitting above.”
“An adult male, Kalunde, aged approximately 29 years, displayed the above flu-like symptoms between September 14 and October 3. During this period, he was observed on 4 occasions (once when he was the focal animal for sampling and 3 times during the focal sampling of other males) using a toothpicklike tool 10-18 cm long. On one additional occasion, he was also seen to make a tool, apparently without using it. He inserted the tool deeply into one of his nostrils, which often immediately stimulated him to sneeze. When he sneezed, a large amount of nasal mucus was discharged onto his upper lip. The mucus was then picked off and quickly ingested. On one occasion, he recovered a dry twig from the ground and removed the leaves from it. He tried to elicit sneezing by pushing the modified stem into one nostril, but in the course of 29 s he failed to do so. He then discarded the tool, picked up a large dry leaf, removed the leaf-blade with his teeth and pushed the modified mid-rib into one nostril. Within 5 s, he sneezed and his nasal passage was successfully cleared. On another occasion, he elicited sneezing only after stimulating both nostrils one after the other. Kalunde was one of several chimpanzees which, because of a badly blocked nasal passage, were breathing with difficulty only through the mouth, because the normal air passage was blocked. The stimulus afforded by the use of this tool forced the accumulated nasal mucus out of his nose. Kalunde ceased to display this type of behaviour after October 3, and by Ocotber 9 he had recovered. The tools were modified from grass stems, mid-ribs of leaves and tiny slender twigs, most of which were recovered from the ground. Although the materials were similar in origin to those used for ant-fishing, except that none was taken from the bark of woody vines [2], they were more slender and much shorter. No other chimpanzees were observed to display this type of tool-using behaviour, despite the fact that most of them were similarly affected by this illness. They all had ample opportunities to observe Kalunde’s technique. On September 17, Nsaba, another adult male, was observed closely watching Kalunde engage in this behaviour.”
“Another individual broke off a stick and pushed it three times into a hole in a tree without, apparently, eating anything: “
“Another juvenile, after carrying sticky bananas, pulled leaves towards him, rubbed his chest with them, then broke off a leaf spray and rubbed again.
“At 07:30, a mixed party of eight chimpanzees (three adult males, two adult females, two subadults, and an infant) was seen feeding on fruits in two neighboring trees in the primary forest. EG and two assistants approached and observed the party, which then split into two parties. One of them consisting of two adult males and an adult female chased a mixed group of monkeys (Cercocebus albigena and Cercocebus torquatus). Afterward, the observers heard a series of pounding sounds that occurred in six bouts, each consisting of 3–4 beats and with a pause of one min between bouts. EG and assistants approached and observed an adult female using wooden tools to extract honey from a cavity containing a beehive of stingless bees (Meliponula sp.) on the large branch of a Daniellia klainei (Ceasalpiniaceae) tree, which was about 25 m in height and 1.8 m in diameter. The height of the spot on which the female extracted honey was about 10 m from the ground. The female held three sticks in one hand and had a leg on the branch. She pounded the entrance of the beehive to widen it with the first stick (later measured 37.5 cm in length and 46 mm in diameter). She then inserted her right hand into the beehive to extract honey and subsequently licked honey from her fingers. The beehive was probably that of a sweat bee, but the species was not identified due to the difficulty of obtaining voucher specimens. After a few minutes, she inserted vertically the second stick (47 cm in length and 3 mm in diameter) to extract honey. Then she used the third stick (112 cm in length and 38 mm in diameter) to enlarge the entrance. The splinters scattered on the ground. After a minute, she inserted the second stick to extract honey. Total observation time was 35 min, at which time the female chimpanzee descended from the tree and moved away from the location at 10:45. All of the raw materials to manufacture the stick tools were taken from the same tree (Ebenaceae, Diospyros sp.), which was located less than 5 m away from the tree containing the beehive. The ends of the first and the third sticks were blunted from impact with the beehive entrance, and the second stick tool smelled of honey.”
“At 09.32 hrs, I saw the unidentified adult male stop eating and bend down a young shoot which he then stepped onto and gripped with both feet, squatted and continued to eat.
“At 09.48 hrs, the unidentified adult male left the tool he had been standing on for 16 minutes and started climbing down the central trunk. McGrew then dropped the tool he had held for 6 minutes and followed. Magic J. was higher in the canopy still eating, but I did not see him drop his stepping-stick, although he had held it with his left foot for over 24 minutes.
“At 10:35 in the morning, EG and two assistants heard a series of pounding sounds about 100 m away from them in the primary forest. While approaching the chimpanzees, the observers heard five bouts of pounding that each consisted of 5–10 beats with a minute pause between bouts. First, we observed an adult male pounding a log with a stick on the ground, but he noticed our presence and immediately stopped it to watch us, then moved slowly away from us. We found another adult male near the end of a log, who also moved away slowly. The log Afrostyrax lepidophyllus (Huaceae) was 10.5 m in length and 146 cm in diameter, with a crack (36 cm in length and 3 cm in width) running lengthwise across the top of the log. The log was hollow inside connecting with the crack and opening at both ends. Two sticks were left beside the log. The first stick Afrostyrax lepidophyllus was dry and hard, 67 cm in length and 4 cm in diameter. This tool was probably used by the chimpanzees to enlarge the crack, due to the battered shape of its one end. The second stick Afrostyrax lepidophyllus was fresh, 97 cm in length and 30 mm in diameter. It was probably inserted into the crack, judging from scratches on its surface. We searched inside the crack and hole and found no food for chimpanzees, but noted that the tree hollow smelled strongly of a particular animal species. No feces or hairs remained, but we estimated the animal to be a mongoose (species unknown) from its odor. Although our observations do not allow robust interpretation of their behavior at present, we speculate that the first male probably pounded and enlarged the crack with the first stick, and drove a mongoose out of the log hole. The second male probably waited at the end open of the log to capture it. On 12 August (EG and two assistants) and 17 September (EG, JY, and two assistants), we revisited the three sites, confirming the evidence of tool use by chimpanzees. On 12 August, we did not find any evidence of tool-use by chimpanzees at the first and the third sites, but found five sticks at the second site. Four sticks were 126, 95, 92, and 74.5 cm in length, and 32, 29, 11, and 16 mm in diameter, respectively. They were left on the ground under the tree in which we had observed tool-use by chimpanzees, and were taken from different tree species (unidentified) 5 m away from the tree of beehive. The one ends of these sticks were battered with brush shape, probably for enlarging the entrance of beehive. The fifth stick remained in the hole and looked thin. These observations suggest that chimpanzees used two kinds of tools as observed before. On the 17th September, we found no evidence of tool use at the second and third sites, but found six sticks at the first site. Judging from the sign of use on the sticks, chimpanzees visited the site at least twice, making and using new sticks. The sticks were divided into three categories. Three sticks (Burseraceae, Aucoumea klaineana) were probably used as pounders (73, 54, and 52 cm in length, and 44, 80, and 45 mm in diameter, respectively). Two sticks (Ebenaceae, Diospyros sp.) were probably used as an enlarger to insert into the beehive to widen the hole (48 and 59 cm in length, and 17 and 37 mm in diameter). One end of each of these two sticks was frayed, probably due to rubbing the wall inside the hole. The sixth stick was made by cutting into strips for use of a sharp-edged tool to slice (21 cm in length and 31 mm in diameter). It still smelled of honey, which would have been a result of chimpanzees inserting the tool into the beehive to extract honey”
“At 13.43 hrs, Nye-muna broke off a short branch from above with his left hand and placed it under his left foot. Holding it between his large and smaller toes, he stepped forward, squatted down and ate.”
“At 16:45 the chimpanzees arrived from the elephant grass (Pennisetum purpurium) plateau on the southern side of Gban and climbed up the kapok tree (Ceiba pentandra) which had large branches extending beneath those of the fig tree. The first individual, Bafu (the dominant male), sat on the base of the branch while the second individual, Aiwa (the third ranking male), proceeded to its mid-point from where he could look up at the fig branch just above him about 170 cm from his branch. (1) Standing bipedally he stretched his right arm up to the fig branch above but it was too high for him to reach. (2) Then he broke a small branch off the kapok tree and removed the thorn bark and side branches with his teeth. Taking the 50 cm straight stick in his left hand, he beat the fig branch but it would not fall nearer. (3) At 16:52 he dropped the first stick and broke a new branch. After repeating the same process of manufacture he prepared a hook-type stick (Fig. 6). He then gripped the point A which was nearer to the base, stood bipedally and tried to pull the fig branch which was caught in the side branch of the hook-type stick, but the fig branch slipped away as it approached his hand. (4) After discarding the second stick he took another branch of about 120 cm in length, prepared a hook-type stick again and gripped the point C but the distance B-C was too short. The side branch of the hook-type stick for capturing the fig branch was unable to reach its destination and he again failed. (5) To make a fourth stick of about 120 cm in length, Aiwa bit away the thorn bark but sufficiently only so that it remained hanging to the stick. When he stretched and pulled the stick, the hanging bark became entangled around the fig branch which came half way towards him. All the chimpanzees who were waiting on the kapok tree gave an exciting high pitched call but unfortunately the branch slipped away again. (6) He broke this stick in two, dropped one piece and took the other. The stick was not long enough to reach the fig branch. (7) He then stopped making tools. Gripping his standing branch with both arms and legs, he swung with all his power and when the swinging branch reached its highest point he suddenly stood bipedally and stretched out his left hand. The top of his fingers touched a fig leaf but he failed to grip it. The waiting chimpanzees again called and barked synchronously. (8) He next broke off a big curved branch of 250cmin length and using a similar process of manufacture to the above, prepared a long curved stick but it was too heavy for him to control its use. (The stick weighed more than 1,000 g.) (9) Dividing the long stick into two he prepared a shorter hook-type stick of length 120 cm and weight 800 g but discarded the curved part. He gripped the point C, stretched and caught the fig branch, but on its way to his hand the branch again slipped away. If he had remained sufficiently patient to try three or four times he probably could have succeeded in capturing the fig branch but he dropped the stick. (10) Incorrigibly persistent he prepared another stick of the hook type, gripped the point A and stretched, but again failed to catch the fig branch. At 17:22, Bafu was unable to wait any longer and came to the same vantage point with a stick of about 80 cm in length in his mouth. Aiwa retreated and Bafu looked up at the fig branch. However, without trying to stretch the stick upwards, he dejectedly returned to his own position. (11) Aiwa moved back to the vantage point and broke off most of the nearby branches. He did not prepare any sticks but dropped the branches without hesitation. The main branch on which he was sitting became lighter and rose slightly. He swung on it with all his power as before, stood up and stretched out his left hand. He slightly touched a fig leaf, but it slipped away. (12) Aiwa repeated the same process and at last, at 17:36, he succeeded in catching a fig twig. It was then 51 min since he had begun his endeavors. All the waiting chimpanzees made a hooting and booming noise with tree shaking. Aiwa climbed onto the fig tree and uttering high pitched calls ran throughout the tree for 2 rain without eating the fig fruit which he had sought to reach for so long. At 17:37, Bafu came to the vantage point, prepared a stick and stretched it upwards. The stick beat the fig branch but he was unable to pull it towards him. At 17:50 Bafu returned to his place and Tua (the second ranking male) approached the vantage point. (1') Tua swung the main branch, stretched his hand up like Aiwa and touched a fig leaf but failed to catch it. (2') He broke off a long slender branch and prepared a stick of length 174 cm and weight 1,000 g (Fig. 7). He then beat the fig branch. The stick caught in the fig branch but the latter slipped away. (3') He raised the long stick as high as possible and placed its upper part on the fig branch keeping the other end in his left hand. The fig branch hung down under the weight of the stick which he gripped standing bipedally and stretched up his right hand. The waiting chimpanzees made a hooting and booming noise. Tua, with the long stick in his hand, climbed up the fig branch. Immediately Tua was on the branch, Bafu ran to the vantage point and captured the fig branch which was hanging down under the weight of Tua. Bafu was then able to climb up too. Nina (a mother) with a baby (Nyu), Parna (a young adult female), Non (an adolescent male), and all the waiting chimpanzees captured the fig branch before he had left the hanging fig branch. All the chimpanzees became strongly excited and made a booming noise. Non tightly embraced his mother, Nina, face to face giving an exaggerated excited gesture with grins and uttering a high pitched vocalization. It had taken Tua 5 min to capture the fig branch. “
“At the site where the young shoots had been pulled out, a vertical hole was left at the heart of the crown. Picking up a removed leaf, the chimpanzees used its petiole as a pestle to repeatedly pound and deepen the hole (PO: Fig. lc, Fig. 3). Both hands were used for pounding except for a few one-handed cases. They continually pounded an average of 10.0 times (n=38, S.D.=5.31) per PO component. Then they put the tool aside, inserted their arm into the hole to extract and eat the juicy fibrous products (EX: Fig. ld) which were produced in the hole as a result of the pounding behavior. The hole was deepened to such an extent that they sometimes thrust their arm inward up to the shoulder. After pounding, they drew out the pestle tool to which the edible juicy products still adhered. They often licked its end and their drenched hand (LI). By chewing a mass of fiber, three chimpanzees were observed in 1990-1991 to make a sponge which they used for obtaining juice by repeatedly dipping it into the hole and then sucking”
“Attacking throws by the dominant male (Bafu) and the third male (Aiwa) were as follows. They broke off the biggest dead branch which was immediately available, carried it in their hand, ran along a branch which stretched above the authors making exaggerated attacking gestures and threatening vocalizations, stopped just above the enemy (one of the authors), swung the dead branch in their hands, and then threw it under-arm. The length and weight of the branches which were thrown by the adult males were 100-190 cm and 1,000-3,5(30 g, respectively (Fig. 2). However, the branches thrown by adolescents and juveniles were smaller, usually 40-100 cm and less than 1,000 g. The throwing was well controlled, especially that by adult males, and on a few occasions the branches hit one of the authors and his research apparatus which was kept nearby. These actually represented severe attacks for the authors when standing or sitting on a steep hill with no means of quick escape. However, the throwing by females and juveniles was not well controlled since they did not come just above the enemy. Most throwing was performed by the under-arm method but two cases by the third adult male (Aiwa) were side-armed and six by an adolescent female (Kure), juvenile males (Vu, Jima), and an infant-3 male (Yiri) were over-armed. After swinging the arm vigorously, the branch was released: Its speed was greater than in under-arm throwing but the throwing was not well controlled except in the case of Aiwa.”
“Case 1. In July 1984, an adult female and her presumed daughter (aged about 5 yrs) were watched at an Apis hive for 55 min. A second adult female and her juvenile daughter were also present but were not seen to use tools. The mother was at the hive 16 m up in a large tree when observation began and worked intently, with the same stout stick tool, for 33 rain. She alternated strong levering and pushing motions of the tool in the hive with longer bouts of licking and sucking the end of the tool. Lumps of honey comb were also extracted by hand. After 10 min, the juvenile approached and sat beside her mother and obtained a lump of honey comb from her. Seventeen min later, the juvenile climbed to the crown of the tree, 4 m above the hive, and broke off a small branch which she stripped of leaves but then discarded. She immediately broke a second branch, stripped it of leaves and carried it in her mouth as she returned to sit beside her mother. When the adult female dropped her tool and left the hive, her daughter immediately took her place and spent 22 min extracting honey with her tool, ignoring the second juvenile who attempted to start play by slapping her back. The juvenile left the hive when the two adult females descended to the ground and moved away. “
“Case 2. In April 1994, a group of chimpanzees were encountered and three were close together in a tree when seen. Two (an adult female and juvenile) descended to the ground and left when the observers were detected but the third, an adult female remained. Despite showing distress (hoo vocalizations and screams) at the proximity of observers, she moved to a tree closer to the observers and 20 rain later made a tool and carried it to the original tree which she reached by walking along a liane. She lay along a thick dead branch and used the tool for 12 rain, inserting it repeatedly into a Meliponula hive. “
“Chimpanzees used a perforating twig to open the exit holes on the surface of a nest and then inserted a fishing probe to extract termites. Often after unsuccessfully attempting to open termite exit holes manually, chimpanzees manufactured a perforating tool to open these holes. Tools were held between the thumb and lateral side of the index finger, or between the index and middle fingers. The tip of the tool was pressed into the surface of the nest and sometimes moved in a circular motion until the exit hole had been cleared. The chimpanzee then inserted a fishing probe into the cavities of the nest to extract termites. The form of these tools varied from small, straight twig segments only a few centimeters long to large, unwieldy branches with several leafy twigs attached. Some chimpanzees premodified the tool by clipping the length and removing leafy material, while others left the tool unmodified. The ends of these tools were often slightly frayed (up to 2 cm) from the motions of pressing the stick into the exit hole and removing soil from the canal. We also observed chimpanzees intentionally sharpening the end of the tool by removing a part of the tool tip. In contrast to termite-nest-puncturing sticks, perforating twigs were made from any suitable materials that were in close proximity to the termite nest, regardless of species.”
“During the final six months, at the artificial feeding area, three adolescents, independently, used sticks to try to open boxes containing bananas. After pulling and pushing at the boxes for up to 5 min, each one broke off a stick and stripped it of leaves. Two individuals then tried to push their sticks under the box lids. The third pushed his into the bananas through a hole in the bottom of the box. None of the three had seen either of the others trying to solve the problem in this way.”
“Figure 1 (see also electronic supplementary material, ESM, S1) shows a typical sequence of drinking behavior by an adult chimpanzee named Tua. This episode occurred on the 13th day from the beginning of this study. Tua came around the tree alone and stopped and looked at the video camera for a second. Then he went to the tree, saw the water in the hollow and changed his posture to a bipedal one (Fig. 1a). He looked around, walked to a stem of H. braunianum, located 1 m away from the hollow, and tore two leaves from the plant with his right hand. Then he turned back to the tree with the leaves. He stuffed the leaves into his mouth without chewing them (Fig. 1b), and took them out again with the right hand. Using these leaves he started drinking water by soaking them in the hollow (Fig. 1c), picking them up, and sucking water from them (Fig. 1d) without moving his jaws. Again, he took the leaves out of his mouth, repeating these drinking actions three times. Suddenly he reached out again to H. braunianum, tore off a leaf, and added the leaf, without dropping it, to the first ones. He repeated drinking actions 19 more times, and then removed the leaves from his mouth and left the tree. The total duration of this episode was approximately 2 min”
“I saw club use for the first time in 2006. One young adolescent male and 1 juvenile male both used sticks ca. 60 cm long and 1.5 cm in diameter to hit an adult female (the same individual, but on different days) on the back while she rested. The same juvenile male later hit an adult male with a stick during play and was responsible for both cases of branch-throwing. α-male BT hit an estrous female repeatedly with a 1.5-m stem of Aframomum sp. during a melée in which she and many males were targets of displays and other aggression. Club use involved direct overhand motions”
“In 1977, an adult female chimpanzee of group K (CH) and her male infant (KB) were seen to ingest P. militaris living in a stick of sugar-cane which was bought as bait for the chimpanzees. On June 23 when they happened to notice some workers and soldiers of P. militaris inside pieces of sugar-cane, they stripped off the outer lignified part with their incisors and immediately licked up the insects directly from the sugar-cane. “
“In all observed cases, chimpanzees used one hand in a ‘‘power grip’’ to jab the tool downward multiple times into the cavity. In the single instance in which a chimpanzee was observed to extract a bushbaby, it was unknown whether the prey was alive or dead after the use of the tool, but it made no attempts to escape, nor did it utter any vocalization. In that case, the chimpanzee ultimately broke off the terminal end of the hollow branch by moving several meters up the large (>10 cm diameter) branch and jumping on the branch until it broke off. She then climbed down, reached into the cavity, and pulled out the bushbaby.”
“In some cases, several leaves were used simultaneously as a ‘‘leaf sponge.’’ A 6-year-old male (MC) dipped a fruit of Ficus thonningii in a water puddle, sucked it once, and discarded it [cf. a similar behavioral pattern, wadgedipping, was reported in Taı¨ chimpanzees (Boesch 1991)]. In addition, use of a ‘‘tool-set’’ (sensu Sugiyama 1997) was observed twice: a 5-year-old female (JD) and a 6-year-old male (MC) used a stick (or a leafstalk) to pick a leaf sponge out of a tree hole.”
“Observation 1 (18/07/2017, 14:10:44) Cambeque (secondary open forest). Adolescent male inspects a BM hive, inserts his finger into the small opening, pulls it out and smells it, looks around, with his right hand breaks a twig with many attached leaves, puts the proximal end in his mouth, inserts the same end into the hive, brings the tool back to his mouth, smells it, inserts it again, this time deeper, inspects it again, discards tool, tries to widen the hive’s entrance with his middle finger, extracts some of the wax, smells finger and leaves.”
“On 15 February 1989, two chimpanzees, one adult female and one immature, were observed ca. 30 m up in a Manilkara sp. (Sapotaceae) tree. The observer (R.W.C.) was drawn to the tree by the booming sound of pounding on hollow wood. Upon arrival the adult female was using a blunt stick to open a honey bee hive in a broken, ca. 30 cm diameter primary branch. It pounded several times with the stick in the right hand while holding on to the top of the stump with a fully extended left hand. After several blows with the stick the chimpanzee propped it up against the stump and reached into the hive to the full length of the right arm. It then licked honey from her hand, retrieved the pounding stick and inserted into the hole and slowly extracted it. The female ate the honey off the stick while the immature chimpanzee approached. The immature was presented the end of the stick still held by the adult. The immature accepted honey off the stick then replaced the adult female at the branch stump and reached into the hole with its hand. At this point the chimpanzees became aware of the observer and moved higher into the tree without vocalizing.”
“On February 5, 1994, at 07.26 hrs, I came within 18 m of Namaska, with her new infant, Keekeh, clinging ventrally, and Hess eating Ceiba pentandra fruits. Namaska was eating fruits while sitting on a short branch that was still attached but bent down beneath her. Namaska did not move until 07.53 hrs when Hess started climbing down the tree, as if he was leaving. Namaska immediately left the seat-stick behind, placed the fruit she had been eating in her mouth and followed.”
“On January 18, 1997, at 08.08, M.M., S.H., and P.G. (a local assistant) encountered a 16-year-old male named Foaf around the top of Mt. Gban, in the core area of the chimpanzees’ home range. The humidity at about 08.00in those days was nearly 100% according to a hygrometer placed on a tree in the forest. Mt. Gban was covered in mist, especially near the top, leaving the ground evidently wet. Foaf was in the sitting position at the time of the encounter, resting on a path about 15 m ahead of the three observers. The presence of three other chimpanzees was noted on nearby trees, where they normally stay when the ground is wet from the early morning mist. The path ran straight between Foaf and the observers, so visibility was very good. However, he was sitting behind the but-tress root of a Triplochiton scleroxylon tree, which hid his waist and legs from view. After he left, we proceeded to investigate the site more closely, and found five leaves of the carapa tree (Carapa procera) at the exact location where Foaf had been sitting (Fig. 2). The five leaves were arranged side by side on the ground. Four of the five lay face up, and the remaining leaf was folded in two. The tips of all the leaves were oriented in the same direction. Chimpanzee hair was found on the ground about 2 cm from the end of the leaves. The leaves had wrinkles, dents, and folds, indicating that they had been pressed down. They showed no signs of having been broken off. We thus saw Foaf sitting on the spot but did not see him handle the leaves or arrange them side by side. However, it would appear unlikely that he had just happened to sit on leaves that had naturally fallen in such a configuration. We can say with certainty that the leaf arrangement was not a human construction, as Mt. Gban is considered sacred, and no one except for researchers and only two local assistants strolls its forests. We therefore suspect that Foaf had collected the fallen leaves and arranged them on the ground by himself. Carapa trees were abundant nearby, and there were several other fallen carapa leaves lying in close range, but none of those were arranged in a pattern similar to the surmised leaf cushion. The carapa tree is a predominant species at Bossou.”
“On June 24, 1978 (at the beginning of the dry season), 2 adult female chimpanzees (WD and WL; WD with a dependent infant male, MA) of group K were observed to insert probes into a mound of P. spiniger (fig. 2), but they did not obtain any termites (observer: Ramadhani Nyundo)”
“On November 23, an adult male (SB) tore off a thin shoot (approximately 17 cm in length) from a small liana, and pointed it down to the surface of the ground while holding one end of it with his right hand so that the other end touched termites moving in a line on the ground. After several seconds he noticed a termite climbing up (or biting at) the shoot and ate it. However, he did not repeat the action. ”
“On November 24, 1977, after giving two sticks of sugar-cane to group K. chimpanzees in the bush, the author followed a subgroup of 8 individuals consisting of 1 old female (WT), 3 adult females (CH, WA and WD), 1 adolescent female (GM), 1 juvenile male (LL), and 2 infant males (KB and MA) until they arrived at a mound of P. spiniger in the gallery forest on the right bank of upper Hasala Valley (fig. 2). WT prepared a fishing probe at the place where she was given some bait and, holding it between her lips, took it to the termite mound. Other individuals made tools near the mound, and all except MA (who was only 2 months old) fished or tried to fish for termites at least once. Another adult female (GW) appeared on the scene after 23 min and joined the termite-fishing session”
“On October 27, an old male (KM) was observed to take a dead twig 10-20 cm in length and to put the tip of it onto the exposed surface of the ground where several termites were seen, but he soon ceased this activity (observers: Almasi Kasulamemba and Moyo Uehara). It was not confirmed whether or not he actually ingested some termites”
“On one occasion the infant, after using one small leaf as a [drinking] tool, tucked this into her groin and then picked and used another leaf of the same size. On another occasion she picked and crumpled two leaves, pushed them into the bowl, which was dry, and left them there.”
“On the ground, the chimpanzee first collects about 12 to 15 nuts by picking them in the tree or, later in the season, by collecting them on the ground, and carries them to an anvil, i.e. a surface root close to the nut tree or a nearby flat rock. Most of the rootanvils show a depression or a hole produced by previous nut-cracking. In 75 ~/o of the 748 recorded Coula-cracking places on the ground, a hammer, most frequently a wooden club, lay on or beside the anvil. When no hammer was near, the chimpanzees were seen to look for an appropriate one and carry it to the anvil in one hand. They would then sit down and start to pound the nut, holding the hammer with one or both hands. Each nut is immediately eaten after opening and thehammermeanwhile rests on the ground. Before beginning to work on the next nut, the shells are brushed from the anvil with one hand. Nuts are usuallycollected several times during one feeding session. “
“On three occasions male chimpanzees threw stones at baboons which approached too closely. One male threw overarm three times in succession, first a handful of leaves and then two small stones, none of which hit their objectives.”
“On two different occasions a mature male threw rocks towards the expedition photographer whose presence was making the chimpanzee afraid to approach a box of bananas. One rock weighed 6-8 lb. and the other was twice as heavy. Both were thrown underarm (the second with two hands) and travelled about three yards in a direct line with their objective, falling short by 1 ft. and 3 ft. respectively. The third incident" occurred when the presence of the photographer prevented an adolescent male from approaching to investigate a toy chimpanzee tied to a tent pole. He picked up a small stone and threw it underarm in a direct line with the photographer. It went 5 yards, but fell short by 4 ft.”
“On two occasions I saw an infant approximately 18-22 months old 'fishing' for termites. Every 10 min or so she broke off to play around for a few minutes, or to watch other individuals, before returning to work. This was unlike older individuals, who frequently worked for more than 1 h with intense concentration. This infant showed the complete adult pattern, but her technique was not fully developed. Her tools were too short to be completely effective (the longest I measured was only 2 in.) and after pushing one into a hole she pulled it out immediately, usually jerking off any termite which had caught hold. Twice she picked up small pieces of dried stems which were lying beside her for use, and twice she made tools by stripping the paired leaflets off side-stems which another individual had stripped from a main stem to make a tool. Once she reached up to try to take the grass tool from the mouth of her adolescent sibling.
“On two occasions the chimpanzees used sticks to feed on different species of ants. One observation involved the underground nest of Dolaris sp. and the other an arboreal nest of Crematogaster (Atopogyne) sp., but in both cases the method used was similar: the chimpanzees (groups of four and five respectively) pushed their sticks into the nests, which had been opened up before my arrival, waited for a moment, withdrew them, and removed the ant-mass on the end with their lips. Most of the sticks used in this way were estimated as between 1 ft. 6 in. and 2 ft. 6 in. long (although I measured one which was 3 ft. 6 in.), and they were either broken from nearby branches or picked up from the ground.”
“On two other occasions sticks were used as tools in connexion with the eating of ants. Once an infant pushed a stick into some loose soil where Dolaris were present: her behaviour was the same as that of an adult, but her tool did not penetrate the nest. Another individual broke off a stick and pushed it three times into a hole in a tree without, apparently, eating anything: through binoculars I saw reddish ants moving around the entrance.”
“Once a female stripped a handful of leaves to wipe mud from her foot. An adolescent picked leaves to wipe off drops of urine which had splashed on to him from a juvenile sitting above. Another juvenile, after carrying sticky bananas, pulled leaves towards him, rubbed his chest with them, then broke off a leaf spray and rubbed again. Mter handling bananas which had been smeared with honey in a feeding experiment, two individuals used leaves to wipe themselves: an infant pulled leaves towards her and rubbed her sticky lips with them, and an adolescent stripped off a handful of leaves with which to rub her other hand. “
“Once, when the water-bowl was nearly empty, the three-year-old animal let go of the leaf mass with which she had been drinking and apparently had difficulty in reaching it again. After a few moments she picked a nearby twig, stripped off the leaves, poked it into the bowl and then licked the end. She next stripped and then picked a second twig and repeated the process. Finally, she tried to drink with her lips and then moved away. “
“One chimpanzee (GW) who joined the session late, for example, appeared on the scene holding a tool between her lips, waited beside another individual who had already been engaged in fishing or looked for other new termite tunnels for 17 min, and then was occupied at two different tunnel mouths for 20 min only to get a few soldiers.”
“One male threw overarm three times in succession, first a handful of leaves and then two small stones, none of which hit their objectives. Two other chimpanzees threw underarm: one individual threw a large stone which travelled about half-way towards a baboon some 10 yards away, and the other threw two small stones, the second of which hit a baboon which was only about 5 ft. away. “
“One of the B type probes was prepared by an old female (WT) and carried for about 500 m before her arrival at the termite mound. Another probe of this type was brought to the mound by an adult female (GW) who held it between her lips. The other 14 were made near the termite mound, within about 5 m in radius”
“One such instance [of throwing towards an objective with definite aim] occurred when an adolescent broke off a stick, took careful aim, and threw it overarm at another chimpanzee below; on this occasion the action was apparently playful.”
“The 2 cases of fishing resemble that described by Sherrow (2005). Both occurred at fallen tree trunks and the identity of the extracted food was uncertain. In the first case (June 5, 2005), 1 adult male, 1 adolescent male, 4 adult females (2 with young infants), 3 adolescent females, and 2 juveniles gathered along a large fallen tree trunk. Much of it was hollowed out, and the chimpanzees clustered in several spots to bite rotting wood from inside the hollows, apparently to extract termites. (Ngogo chimpanzees fed similarly at the same tree trunk on other occasions.) The total feeding session lasted 45 min. PE, a young adult female, fed briefly from the trunk via her teeth at the start of the session, but hesitated to approach a large hollow that appeared to be the best feeding spot, where 2 other older, larger females were feeding with adult male GA. She then moved into vegetation ca. 5 m to the side of the trunk and broke off a flexible herbaceous stem ca. 50 cm long. She stripped several leaves from the stem, carried it to the tree, climbed onto the trunk, and inserted the stem into a small hole directly above a large hollow area. She extracted the stem after a few seconds, inspected it, and reinserted it, repeating the behavior 10 times; several times she brought the stem to her mouth, and once she chewed briefly on its end to modify its form. She obtained little, if any, food; after several minutes, she discarded the tool, climbed down to the base of the trunk, and resumed biting at the inside of a hollow with her teeth.
“Twice she picked up small pieces of dried stems which were lying beside her for use, and twice shc made tools by stripping thc paired leaflets off side-stem'3 which another individual had stripped from a main stem to make a tool. Once she reached up to try to take the grass tool from the mouth of her adolescent sibling. “
“Two other chimpanzees threw underarm: one individual threw a large stone which travelled about half-way towards a baboon some 10 yards away, and the other threw two small stones, the second of which hit a baboon which was only about 5 ft. away.”
“We observed chimpanzees use lever-open tools to widen hive entrances to access honey. They inserted the end of the stick into the beehive and rapidly moved it side to side to widen the nest entrance. After the entrance was widened, the chimpanzee either reached into the hive with their hand or used a dip stick to extract the honey. Lever-open tools were medium-sized twig tools, often with secondary vegetation removed. This tool was often made after the entrance of a hive had been cracked or broken from pounding (see beehive pounding). The chimpanzee stopped pounding, traveled into the adjacent canopy, gathered a small stick, removed the side and end twigs, and then inserted it into the hive entrance. The action associated with this tool use was a powerful back-and-forth motion, using the side of the tool to widen the entrance into the hive. “
“We observed two cases of a chimpanzee’s (JJ) ant-fishing behavior in trees at Bossou, one in 2003 and the second in 2005, while following the chim- panzees in the forest. The target ant species was arboreal carpenter ants (Camponotus brutus). The first observation was as follows: on March 6, 2003, G. Y. found JJ (5 years 4 months old at the time) fishing carpenter ants nesting in a hollow in a tree trunk (Carapa procera) 3 m above the ground (Fig. 1A). This tool use session lasted for 12 min 59 sec. In this case, 14 bouts were observed. JJ successfully captured and consumed ants in 3 of the 14 bouts. In each successful bout, JJ held the wand with one hand, swept the wand directly with his lips, and ate approximately three ants. JJ held the wand with his right hand in 13 out of the 14 bouts. In 11 bouts, the wands were held between JJ’s thumb and the side of his index finger, and in the other 3 bouts, they were held in his palm and fingers. JJ was observed shaking some ants off the wand once and sweeping them off twice. JJ was bitten by ants three times. When bitten, it seemed painful and JJ dropped the wand each time.
“With tool in hand or mouth, the chimpanzee approaches the ant nest and inserts the more slender end of the tool into the hole (Plates 4 and 5). The tool is often held with a precision grip in the favoured hand between ball or thumb and side of forefinger. The chimpanzee may release the tool and leave it inserted or move it in a slight swirling motion. In either case it watches carefully until the ants have streamed approximately 2 of the way up the tool, then withdraws it (Plate 6). Most of the ants move up the tool without biting it, giving the appearance of being able to differentiate the inanimate object from the predator. The hand holding the tool shifts it vertical such that its distal end is just below the mouth. Simultaneously the opposite hand (which may have been idle or supporting in a tripedal stance) grasps in a loose power grip the proximal tool end just above the other hand. Immediately the upper hand slides up the length of the tool in a rapid unbroken motion (the ‘pull-through’) (Plate 7). This momentarily catches the ants in a mass which accumulates on the sides of the flexed thumb and forefinger and lateral surface of the moving hand. The mass is about the size of a hen’s egg and contains an estimated 300 ants. As the hand moves up the tool, the mouth opens wide with lips partly retracted. As the hand leaves the wand it goes directly to the mouth, transferring the ant mass into it (Plate 8). Presumably the mass of ants is so jumbled that few can bite the predator before being consumed. The chimpanzee’s mouth closes and the jaws gnash frantically and exaggeratedly, audibly crushing the ants between the teeth. The ants are then normally chewed and swallowed. The whole sequence from withdrawal to ingestion takes 2-3 sec. With longer tools the wand may be transferred to and held in the foot (usually the one opposite to the withdrawing hand) while the hand makes the normal pull-through (Plate 9). This occurs in about half of cases (12 of 23) and appears to make the length of longer tools less awkward, and either way the operation seems equally efficient. When a chimpanzee dips directly from a stream of ants moving on the ground, the tool’s distal end is placed into their midst, with the tool held diagonally. Chimpanzees may also eat occasional driver ants directly from vegetation with the lips or pick them up between thumb and forefinger and transfer them to the mouth. ”
“the authors once observed an adolescent female (Kure) who inserted a hard leaf of Aningueria robusta into a water hole in a tree which had been left after a dead branch had fallen down from the tree. She pulled it up and licked as well as sucked the water without crumpling the leaf. This occurred on May 17 after there had been some rains but no drinking water could be found in the forest except in such hollows in trees. She repeatedly tried to drink water for 5 min”
“the chimpanzees (groups of four and five respectively) pushed their sticks into the nests, which had been opened up before my arrival, waited for a moment, withdrew them, and removed the ant-mass on the end with their lips. ”
(ii) The second observation occurred in April 2005. As the research team returned to base camp, gorillas were encountered resting and feeding on the main path at a distance of between 8 and 15 m. The silverbacks display consisted of charging, tree shaking and vocalizing at the research team. However, the group as a whole did not appear particularly concerned by the presence of humans nor did the silverback withdraw. One individual, estimated to be sub-adult male, was sitting approximately 8 m from the researchers, chewing on a mouthful of food. This individual picked up a detached dead branch measuring 1.1 m in length and with a diameter of about 15 cm at the thickest point, which was lying in front of him. He threw the branch half-heartedly using one arm and throwing in an underarm fashion sideways at a 45-degree angle, in the direction of the observers. The branch was only thrown about 1.5 m and did not come close to the researchers who were 8 m away. This individual then looked sideways and continued feeding for several seconds before he departed slowly. The silverback male continued to bluff charge and very slowly the group started to retreat. The entire encounter lasted for 33 min.
(iii) On a third occasion, in July 2005, the focal group was observed resting on some rocks situated along a human path in a grassland area. July is the peak of the rainy season but on this particular day it was sunny and we assume the gorillas were basking. The pathway is the main route from one of the local settlements surrounding the base of the Kagwene Mountains. A man from one of the local communities (who is known to the research team) walking uphill from the village approached the gorilla group. The gorillas looked down toward the intruder from about 20 m away. The man is deaf, so would not have heard if the gorillas had vocalized. Upon seeing the gorillas the man stood waiting for them to withdraw, but they appeared not to feel threatened by his presence and stood their ground, occasionally barking. In an attempt to frighten the gorillas away the man began making loud noises by banging his machete on the ground. This resulted only in the gorillas moving closer together and closer to, the man, who began picking up and throwing various stones and small rocks at the gorillas. They did not visibly react at first, but after several minutes some individuals started to tear up grass, bite into it and throw it in the man’s direction, again in an underarm fashion. From the research team’s location, they were unable to see if the gorillas chewed the grass bundles they bit into, but from the rapidity of the action it was assumed, unlikely. In response to the gorillas’ reaction, the man cut some grass with his machete and threw it in their direction. This whole encounter lasted for over an hour, ending with the gorillas calmly moving away from the area. The research team observed this interaction from another hilltop, and could not identify the stones thrown, but estimated they were approximately 10–15 cm in diameter. After the encounter the research team questioned the man, and through gestures he explained that he always avoided the gorillas and had never thrown anything at them before. We cannot be certain that this is true but during this encounter, the man did attempt other methods to frighten the gorillas away before he began throwing items”
One young male gorilla, holding a long stick in his hand, charged at a trapper. Before reaching his objective, however, he stopped, dropped the stick, and retreated (Kortlandt and Kooij, 1963)
“During the 2 hr monitoring visit, Kigoma, the second ranking silverback, was observed to use his left hand to collect driver ants (Dorylus sp.) from ahole in the ground. When he first inserted his hand into the hole, he quickly withdrew it and ran from thehole while shaking his left arm, presumably to remove the biting ants. Lisanga, a juvenile female,was approximately 6 m away from Kigoma at this time and observed him eating the ants and running away. She then approached the hole and watched the ants entering and exiting the hole for approximately2 min. She proceeded to insert her left hand into thehole, but quickly withdrew her hand covered in ants,shaking her arm vigorously, again presumably due to painful ant bites. She was then observed to select a piece of wood off the ground that was approximately20 cm long and 2 cm wide at one end, 1 cm wide at the other. The piece of wood was a freshly broken branch,thought to be from a tree found 2 m from the ant hole.She inserted the stick into the hole and then withdrew the stick, licking the ants off of the stick.After licking the ants off the stick, Lisanga ran away shaking her left hand to remove the still biting ants.No other gorillas appeared to have witnessed Lisanga using the stick nor were any other gorillas observed trying to eat ants during this observation period.”
“On 9 October 2004, we observed George’s group (monitored since 1995) near the edge of the clearing 180 m from the observation platform. This group had not been observed to use this area for more than 6 mo, and meanwhile elephants had created a new pool to feed on soil. Adult female Leah was seen at the pool edge near where a branch was sticking out of the surface, looking intently at the water in front of her for 1 min before she entering the water (Figure 1, top left). She began to cross the pool walking bipedally, but after her first steps the water quickly became waist deep and she returned to the pool edge. Leah then re-entered again bipedally and grabbed the straight branch in front of her with her right hand (Figure 1, top center). Relative to Leah’s body size we estimated the leafless branch as being approximately 1 m long and 2 cm thick. Leah then detached the stick and, stretching forward with it in her right hand, seemed to use it to test the water depth or substrate stability: she grasped the stick firmly and repeatedly prodded the water in front of her with the end of the stick (Figure 1, top right). She then moved further into the pool, holding the detached branch in her right hand and using it as a walking stick for postural support (Figure 1, bottom three images). She advanced a further 8–10 m from the pool edge (not shown), repeating the actions shown in Figure 1, and then, leaving the stick in the pond, returned to her entry point, where her offspring was crying. She did not re-enter the water, but instead moved around the pool to feed on aquatic herbs.”
“On November 30, 2010, Group Pablo was in the bamboo zone at an altitude of ca 2800 m. Nutrient-rich bamboo shoots are available twiceper year, at whichtime the bamboo zone constitutes the gorillas’ preferred foraging grounds. The vegetation in the bamboo zone is characterized by dense thickets of Yushania alpina interspersed with some open herbaceous fields. At 09:09, adult female Tamu was sitting ca 2–2.5 m above the ground on a thicket of bamboo and herbaceous plants where she was feeding. At 09:10, her infant Imbuto (age 12 months) was seen walking on the ground in the direction of his mother and was uttering distress vocalizations. Immediately after the vocalizations, Tamu became alert and stopped feeding. The infant met its mother’s gaze when he was ca. 4 m from the bamboo thicket. He moved to the base of the bamboo thicket and attempted to climb up by grasping herbaceous/shrubby vegetation, which repeatedly became dislodged from the pile by the infant’s weight. The only item providing reasonably firm support was a hard bamboo shoot that Tamu had detached a few minutes before. At 09:11, Tamu was in a sitting position and holding one end of the bamboo pole, which hung vertically to nearly the bottom of the vegetation pile. The infant grasped the pole, at which time the mother repositioned herself by turning ca 45 degrees in the direction of the infant, bending over the edge and looking at the infant. She then held the pole firmly with one hand (without adjusting the angle or position of the pole), which permitted the infant to climb up as one would do on a ladder (Fig. 1). She carefully observed the infant during the climbing process. After the infant had reached the top of the pile and was reunited with his mother, the mother did not resume her feeding activities, but started resting instead.”
“On three separate occasions we recorded behaviors that satisfy Beck [1980]definition of tool use. (i) The first observation was recorded in December 2004 during a gorilla–human encounter in a grassland area. In this instance, the silverback chargedto within 5 m of the research team who were located lower down the steep slope ofa hill. Seven adult gorillas were standing behind the silverback at a distance ofbetween 7 and 10 m. Four of them retreated, whilst three others remained near the silverback, who continued to bluff charge the research team. These three non-silverback individuals began tearing up fistfuls of grass with roots and mud attached, and throwing them in the direction of the researchers. This continued for over 3 min during which time the three gorillas threw grass several times using an underarm motion. All attempts were clearly aimed at the human observers but none of the projectiles actually hit their target, all falling less than 2 m short of the team.
“The second observation involved female Efi from Zulu group (monitored since 2000), who entered the clearing on 21 November 2004, 150 m from the observation platform. While close to the forest edge Efi detached a 1.3-m-long and 5-cm thick leafless trunk of a dead shrub with both hands. She forcefully pushed it into the ground with both hands (Figure 2, middle) and held the tool for support with her left hand over her head for 2 min while dredging food with the other hand (Figure 2, bottom). Efi then took the trunk with both hands and placed it on the swampy ground in front of her, crossed bipedally on this self-made bridge, and walked quadrupedally towards the middle of the clearing (not shown). We could not see if the bridge was long enough to cross the swampy ground, but it certainly gave the female more stability underfoot and supported her weight for at least part of the distance”
I n S e p t e m b e r 1981, the female Cro (...) bringing her f o o d t o wash it a t a watering s p o u t several meters a w a y f r o m the f o o d source. (...) a n d few d a y s later the m a l e R o l did likewise.
I n S e p t e m b e r 1981, the female Cro (...) bringing her f o o d t o wash it a t a watering s p o u t several meters a w a y f r o m the f o o d source. T w o d a y s later, the males R o m a n d M a u were seen b e h a v i n g in the s a m e way, a n d few d a y s later the m a l e R o l did likewise.
I n S e p t e m b e r 1981, the female Cro (...) bringing her f o o d t o wash it a t a watering s p o u t several meters a w a y f r o m the f o o d source. T w o d a y s later, the males R o m a n d M a u were seen b e h a v i n g in the s a m e way, a n d few d a y s later the m a l e R o l did likewise.
I n S e p t e m b e r 1981, (...) bringing her f o o d t o wash it a t a watering s p o u t several meters a w a y f r o m the f o o d source. T w o d a y s later, the males R o m a n d M a u were seen b e h a v i n g in the s a m e way
In July and September 1985, respectively, the individuals Bee and M a d were observed using the watering spouts to wash their food.
In July and September 1985, respectively, the individuals Bee and M a d were observed using the watering spouts to wash their food.
T h e second uses only one h a n d : the same h a n d holds the piece o f f o o d a n d simultaneously presses the spout (with the side o f the hand), the water flowing over the f o o d (Fig. 2b). In August 1983, this b e h a v i o u r appeared in the males M a t a n d Coe
The first involves the use o f b o t h hands: holding the piece o f food, one h a n d touches the spout to eject the water, and the other makes the washing movements (Fig. 2a). T h e second uses only one h a n d : the same h a n d holds the piece o f f o o d a n d simultaneously presses the spout (with the side o f the hand), the water flowing over the f o o d (Fig. 2b). In August 1983, this b e h a v i o u r appeared in the males M a t a n d Coe
The low-water rocks of the islands of the Mergui Archipelago are covered with oysters, large and small. A monkey, probably Macacus cynomolgus, which infests these islands, prowls about the shore when the tide is low, opening the rock-oysters with a stone by striking the base of the upper valve until it dislocates and breaks up. He then extracts the oyster with his finger and thumb, occasionally putting his mouth straight to the broken shell.
“A unique case of tool manufacture and use by a free-living female bonnet macaque (Macaca radiata) is reported here. This elderly female, approximately 12-15 years of age, was a member of a large troop of 19-22 adults, inhabiting semi-arid scrublands on the outskirts of the city of Bangalore, southern India. She was often observed to insert a short twig, dry stick, stiff leaf or grass blade, or a leaf-midrib into her vagina and scratch vigorously, possibly in response to some irritation that appeared to bother her persistently, whether or not she was sexually cycling, and even during pregnancy. She was found to scratch her genitalia on 18 occasions between March 1993 and September 1994, during which time she was observed for 21 h. Her dependence on object use is shown by the fact that on 15 of these occasions she used a tool for a total of 34 times, while on .3 occasions she used her forefingers alone. What was more remarkable, however, was that on 8 out of the 15 occasions on which she used objects, she actively manufactured or modified her tools in the following ways: (1) Dry Eucalyptus globosus leaves were stripped of their lamina with the fingers or teeth, the midrib was broken into several pieces, and only a single short piece, 1-2 cm long, was used. (2) Dry Acacia auriculiformis leaves were longitudinally slit into halves, and a single half utilised. (3) Short sticks were detached from branched twigs and then used. (4) Dry sticks were broken into several pieces, and only a short piece was used. (5) Twigs or sticks were sometimes rubbed vigorously with the fingers or between the palms prior to use. (It may be added here that bonnet macaques often rub food between their palms prior to ingestion.) “
“In the ease of the snail shell, a very young juvenile was involved. After putting one end of the shell into its mouth for about 2 sec, the monkey "leaf-washed" it between its palms, and then between its palms and the ground, using one foot in the process. It carried the shell in one hand, walking on the other three feet when it. moved. After about 5 min, the shell was discarded.
“In the second case, only the latter part of the activity was seen. The sub-adult male monkey had already wrapped a large yellow leaf around the rubber band and had placed the bundle in its mouth. It pulled a portion of the band protruding out of its mouth about ten inches and released it so that it contracted and struck the teeth and upper lip. In this case too, the rubber band was slowly chewed and consumed. The first rubber band was green, the second white.”
“The first of the two rubber bands mentioned above was sniffed and placed on a large dried leaf, which was partially wrapped around it; it was then rubbed until the leaf disintegrated. After being sniffed again, it was carried in the mouth to a spot a few yards away where it was eaten with slow and irregular chewing movements.”
“The sequence involving the toad began when a subadult male found the toad under a tree. Four sub-adult monkeys examined it in turn, holding it by a hind leg, but did nothing else. An adult male then took the toad and examined it visually and by sniffing. After this, two sub-adult males "leaf-washed" it in turn. Although the toad was sniffed many times, no attempt was made to eat it, and in handling it only the hind limbs were touched.”
“A subadult (unflanged) male was observed feeding on the leaves of a cluster of three trees (Erythrina sp.) in the primarily undisturbed forest portion of the study area. The trunk and branches of Erythrina trees are covered in short, stout, woody thorns. Due to a natural landslide, this cluster of trees was isolated from all but one tree by 10–30 m. The male gathered several (5–10) Erythrina leaves and, by stacking, fashioned them into a pad. Placing the pad on the palm of the hand that supported the bulk of his weight, the orangutan subsequently moved among the thorny branches to feed. When the male transferred his body weight to his foot by grasping the trunk, he preceded this action by transferring the pad to the sole of the supporting foot. Such transfer of the pad between hands and feet occurred several times during the feeding bout. After several minutes, the male replaced the used pad by making another in the same fashion.”
“An adult (flanged) male was observed feeding in a large (30 m) fig tree within the disturbed, semi-cleared forest on the southern border of the monitoring station. Following the feeding bout, the male moved to a smaller tree and nested for approximately 25 min. The male then began traveling arboreally, employing quadrumanous scrambling, toward the primarily undisturbed forest. Before reaching it, the male attempted to transfer between two trees, first by reaching manually for the destination tree, and second by combining reaching with “tree swaying” to bring his tree closer to the destination tree. After both attempts failed, the male moved to a different location in the tree, broke off one of its live branches approximately 2–3 cm in diameter and 1 m long, and returned to his previous position. The branch was relatively straight, with several small leafy branches bent toward its apex. Holding onto the tree with the left hand and the broken-off branch with the right hand, he reached for the destination tree and attempted to “hook” it with the broken-off branch. However, the distance between the terminal branches of the two trees, at 3–4 m, was greater than the length of the branch hook. After two attempts, the male dropped the branch. He then broke off a second branch similar in physical characteristics to the first branch, but more than twice as long (approximately 2.5 m). Using this second branch, the male successfully hooked the destination tree by tree swaying while reaching with the hook. Using the hook, the male then drew the destination tree’s terminal branches to within reaching distance of his foot, and he transferred to the destination
“In eight and a half years only once was an instance of tool-use observed in a context other than agonistic display and/or nesting/covering. An adult male sitting 10-12 m up in an ironwood (Eusideroxylon zwageri) pole tree, broke off the end from a dead branch and, with the left hand, reached under his left thigh and for 30-35 s scratched himself rhythmically with the stick in the vicinity of his anus. Then he put the same stick to his lips and mouthed it for another 10 s before biting a piece off. After slowly lowering his left arm and casually letting the stick drop, he moved away through the trees
“On September 12, 1976 a middle-aged adult male, sitting 10 to 12 na up in an ironwood tree, broke off the end of a dead branch and, with the left hand, reached under his left thigh and for 30 to 35 sec rhythmically scratched himself with the stick in the vicinity of his anus”
“On 33 occasions an adult male sat down, broke offa large stick (70-180 cm in length) with his hands, held the detached stick, and stared at another male. The challenged male either ignored the challenge (11 times) and the stick was dropped after a few seconds, or grabbed the stick and the two males then engaged in a tug-of-war (22 times). This was clearly an adult male activity. The only female who ever took part was a mother who tried to grab the challenging stick away from her low-ranking son before a higher-ranking male engaged in a tugof-war with him. These stick intimidation displays and tug-of-war contests were considered to be dominance interactions amongst males of the same troop and were a way to settle hierarchical differences without resorting to physical contact. These contests appeared to be final settlements since they never led to fights; rather, one male always moved off”
“One young male was first seen brandishing sticks when he was 28.5 months old. Before incorporating sticks into his displays, he went through a brief period (from 24 to 28.5 months of age) of holding the base of his own tail as he ran squealing through a tree. The first time he was observed using a stick, he held the stick next to the base of his tail and only waved it slightly. In subsequent observations, he held the branch in a position so that it was more noticeable and the brandishing became more vigorous. As he got older (and hence larger and presumably stronger and more proficient), the size of his chosen stick increased from approximately 30 cm to 90 cm over a 7-month period. “
“The transition from tail brandishing to stick brandishing was observed in one other young male. In this case, an 1 l-month-old ran squealing through a tree with his left hand on top of, but not actually holding, the base of his own tail. For the next two months he frequently ran through trees squealing and clutching the base of his tail with his right hand. At 15.5 months he began squeal/leaping through trees, holding the base of his tail, biting off pieces of loose bark, and spitting them out. At the age of 20 months, just before he was exiled from his natal troop, he was seen squeal/leaping through a tree, clutching a 30 cm long live Anthocleista procera leaf. “
“Three different types of social object games were observed and are described below: (1) In one instance a 21.5-month-old female broke off a 35 cm long dead branch, banged it against the tree, and sat with a play face looking back and forth from the branch she held to a 33-month-old female sitting 2.5-3 m off (again, it appeared that the branch was used as a form of play invitation). The 33-month-old scampered up, grabbed for the branch, and missed it as the 21.5-month-old pulled it away. This game continued for 40 sec and ended when the 21.5-month-old fell and released her grip on the branch. The apparent purpose of this game was for the initiator of the game to maintain her solid grip on the branch and fol the other to try and take it away. (2) In one instance six female and three male juveniles played with three loose pieces of orange-sized termite mound. Three possessers laid down on top of a piece while six non-possessers pounced on them, wrestled and mouthed them, and tried to get them off the pieces of mound and take possession for themselves. When art individual gained possession of a mound piece, they hit, rolled, jumped on, and laid down on top of it. This game lasted for at least 5 rain, involved many changes in winner-loser positions, and finally ended when a group of tourists arrived and all the participants ran off. It seemed that the purpose of this game was to secure and maintain possession of one of the pieces of mound and to keep others from taking it away. (3) On 24 occasions juvenile and subadult members of the study troop and on two occasions members of neighboring troops played with Anthocleista procera leaves. The players (anywhere from four to ten individuals took part; mean ---- six players) climbed up a Anthocleistaprocera tree to a leaf cluster, detached a 35-85 cm long leaf, waved it about, hit each other with it, and dropped it. The players who had not made it up to the leaf cluster tried to topple the leaf-battlers from the leaf cluster. The leaf-battlers tried to prevent the others from getting to the leaf cluster by swatting, banging, and hitting them with the leaves. It would have been very easy for any of the non-possessers to either pick up one of the dropped leaves or move to another leaf cluster, detach a new leaf, and jump on top of the leaf-battlers. None of the players were ever seen to do this. They appeared to be concerned only with procuring a leaf from the actual leaf-battling arena. This game seemed to have two goals. The first goal was to reach and then maintain a place at the leaf cluster where the play objects were detached. The second goal was to detach a play weapon from the leaf cluster and prevent others from doing the same by using the leaf as a deterent. This game was played for 2-10 rain and it was not clear why it ended.”
“At 11 : 55 on June 23, 1995, after the group had been resting for more than an hour at the top of a 30 m high tree, the adult male suddenly descended the trunk. When it had reached a large clump of epiphytes located approximately 15 m above the ground, a large adult two-toed sloth emerged from the epiphytes (probably Philodendron insigne or P. linnaei) and moved about 1.5 m away from the trunk along a perpendicular branch. The howler stayed grasping the trunk. It then started gently striking the branch the sloth was hanging on to with a short unramified stick (part of a branch or thick liana). The monkey struck 1-2 blows, had a look at the observer and struck 2-3 more blows, always softly and slowly. Its arm was fully stretched, and the held stick hit the branch and the toes and claws of the sloth (Fig. 1). The observer (N.B.) did not see whether the stick was already detached or if the monkey had had to break it off. The sloth was not aggressive and did not show any visible reaction. At 12 : 05, the male howler dropped the stick and quickly left the tree, followed by the rest of the troop. The sloth then rapidly returned and hid in the epiphytic clump. “
Case 1 On 4 June 2005 at 11:27 hours, SML observed an adult female of the Ceiba community holding a small, leafy branch in her hand, which she used to scratch her thoracic and abdominal regions. The subject was part of a mixedsex subgroup of at least eight individuals.
Case 2 Later that day, SML encountered a mixed-sex subgroup of at least six individuals within the Ceiba community. At 15:56 hours, an adult female used a stick, lacking side branches and leaves, to scratch her left axilla region. She chewed the tool tip between scratching bouts. It could not be determined whether this female was the same individual from the first case.
Case 3 On 21 June 2006, MAR observed a party of at least four individuals of the Pilo´n community. At 15:59 hours, a juvenile female used a stick to scratch her anogenital region and the underside of her tail. Before using the tool, she chewed the distal tip and applied this end to her body