Animal Cognition

, Volume 14, Issue 5, pp 683–693 | Cite as

Local traditions in gorilla manual skill: evidence for observational learning of behavioral organization

  • Richard W. ByrneEmail author
  • Catherine Hobaiter
  • Michelle Klailova
Original Paper


Elaborate manual skills of food processing are known in several species of great ape; but their manner of acquisition is controversial. Local, “cultural” traditions show the influence of social learning, but it is uncertain whether this includes the ability to imitate the organization of behavior. Dispute has centered on whether program-level imitation contributes to the acquisition of feeding techniques in gorillas. Here, we show that captive western gorillas at Port Lympne, Kent, have developed a group-wide habit of feeding on nettles, using two techniques. We compare their nettle processing behavior with that of wild mountain gorillas in Rwanda. Both populations are similar in their repertoires of action elements, and in developing multi-step techniques for food processing, with coordinated asymmetric actions of the hands and iteration of parts of a process as “subroutines”. Crucially, however, the two populations deal in different ways with the special challenges presented by nettle stings, with consistently different organizations of action elements. We conclude that, while an elaborate repertoire of manual actions and the ability to develop complex manual skills are natural characteristics of gorillas, the inter-site differences in nettle-eating technique are best explained as a consequence of social transmission. According to this explanation, gorillas can copy aspects of program organization from the behavior of others and they use this ability when learning how to eat nettles, resulting in consistent styles of processing by most individuals at each different site; like other great apes, gorillas have the precursor abilities for developing culture.


Great ape Gorilla gorilla Imitation Technique Feeding skill Animal culture 



The Port Lympne data were collected by CH, who would like to acknowledge the financial support of the European Commission Sixth Framework Program grant “Origins of Referential Communication” Contract 12787. MK acknowledges the support of the University of Stirling and Metro Toronto Zoo for her Ph.D. funding. We thank the Howletts Wild Animal Trust for permission to conduct the study at Port Lympne Wild Animal Park, and in particular we are grateful to Pippa Ducat, Mark Kingston Jones and Charlie Romer for their assistance in planning the project and gathering information. We thank all the staff members of the gorilla section for so generously sharing their invaluable knowledge and assistance. In particular head keeper Phil Ridges, along with fellow keepers Helen Roberts, Ingrid Naisby, Rachel Wood, Sharon Tremaine and Julia Betts. We thank Claudio Tennie for stimulating discussions, and for allowing us to use his video exemplars.

Supplementary material

ESM_1 Video of mountain gorilla processing nettle in group-typical way (MPG 4409 kb)

ESM_2 Video of captive gorilla processing nettle; file kindly provided by Dr. Claudio Tennie, who noted that this video was “typical” of the behavior analyses in Tennie et al. (2008) (MPG 4782 kb)

10071_2011_403_MOESM3_ESM.doc (48 kb)
ESM_3 Table giving full definitions of action elements identified during the current study (DOC 48 kb)
10071_2011_403_MOESM4_ESM.doc (243 kb)
ESM_4 Flowcharts of individual Port Lympne gorillas processing nettle (DOC 243 kb)
10071_2011_403_MOESM5_ESM.doc (28 kb)
ESM_5 Comparison of general features of nettle processing behavior, between Port Lympne and Karisoke (DOC 27 kb)
10071_2011_403_MOESM6_ESM.doc (25 kb)
ESM_6 Detailed description of the two nettle processing techniques used by Port Lympne gorillas (DOC 25 kb)

ESM_7 Video of Port Lympne gorilla Djala using the leaves-separate technique for processing nettles (MPG 6862 kb)

ESM_8 Video of Port Lympne gorilla Kishi using the leaves-separate technique for processing nettles (MPG 8080 kb)

ESM_9 Video of Port Lympne gorilla Jaja using the leaves-separate technique for processing nettles (MPG 15024 kb)

ESM_10 Video of Port Lympne gorilla Dishi using the leaves-separate technique for processing nettles (MPG 8034 kb)

ESM_11 Video of Port Lympne gorilla Kibi using the leaves-separate technique for processing nettles (MPG 8230 kb)

10071_2011_403_MOESM12_ESM.tif (2.6 mb)
ESM_12 Photo of Laportea alatipes, taken at Karisoke (TIFF 2612 kb)
10071_2011_403_MOESM13_ESM.jpg (223 kb)
ESM_13 Photo of European Urtica dioica (JPEG 222 kb)

ESM_14 Video of captive gorilla using the action described by Tennie et al. (2008) as “folding”; file kindly provided by Dr Claudio Tennie (MPG 724 kb)


  1. Altmann J (1974) Observational study of behaviour: sampling methods. Behaviour 49:227–265PubMedCrossRefGoogle Scholar
  2. Bates LA, Byrne RW (2010) Imitation: what animal imitation tells us about animal cognition. Wiley Interdisciplinary Rev Cogn Sci doi: 10.1002/wcs.77
  3. Bauer PJ (1998) If it is inevitable, it need not be imitated. Behav Brain Sci 21:684–685CrossRefGoogle Scholar
  4. Boesch C (1996) The emergence of cultures among wild chimpanzees. In: Runciman WG, Maynard-Smith J, Dunbar RIM (eds) Evolution of social behaviour patterns in monkeys and man. The British Academy, London, pp 251–268Google Scholar
  5. Boesch C, Tomasello M (1998) Chimpanzee and human cultures. Curr Anthropol 39:591–614CrossRefGoogle Scholar
  6. Boesch C, Marchesi P, Marchesi N, Fruth B, Joulian F (1994) Is nut cracking in wild chimpanzees a cultural behaviour? J Hum Evol 26:325–338CrossRefGoogle Scholar
  7. Byrne RW (1999a) Cognition in great ape ecology. Skill-learning ability opens up foraging opportunities. Symp Zool Soc Lond 72:333–350Google Scholar
  8. Byrne RW (1999b) Object manipulation and skill organization in the complex food preparation of mountain gorillas. In: Parker ST, Mitchell RW, Miles HL (eds) The mentality of gorillas and orangutans. Cambridge University Press, Cambridge, pp 147–159CrossRefGoogle Scholar
  9. Byrne RW (2001) Clever hands: the food processing skills of mountain gorillas. In: Robbins MM, Sicotte P, Stewart KJ (eds) Mountain gorillas. Three decades of research at Karisoke. Cambridge University Press, CambridgeGoogle Scholar
  10. Byrne RW (2003) Imitation as behaviour parsing. Philos Trans R Soc Lond B 358:529–536CrossRefGoogle Scholar
  11. Byrne RW (2007) Culture in great apes: using intricate complexity in feeding skills to trace the evolutionary origin of human technical prowess. Philos Trans R Soc B 362:577–585CrossRefGoogle Scholar
  12. Byrne RW, Byrne JME (1991) Hand preferences in the skilled gathering tasks of mountain gorillas (Gorilla g. beringei). Cortex 27:521–546PubMedGoogle Scholar
  13. Byrne RW, Byrne JME (1993) Complex leaf-gathering skills of mountain gorillas (Gorilla g. beringei): variability and standardization. Am J Primatol 31:241–261CrossRefGoogle Scholar
  14. Byrne RW, Russon AE (1998) Learning by imitation: a hierarchical approach. Behav Brain Sci 21:667–721PubMedGoogle Scholar
  15. Byrne RW, Stokes EJ (2002) Effects of manual disability on feeding skills in gorillas and chimpanzees: a cognitive analysis. Int J Primatol 23:539–554CrossRefGoogle Scholar
  16. Byrne RW, Corp N, Byrne JME (2001a) Estimating the complexity of animal behaviour: how mountain gorillas eat thistles. Behaviour 138:525–557CrossRefGoogle Scholar
  17. Byrne RW, Corp N, Byrne JME (2001b) Manual dexterity in the gorilla: bimanual and digit role differentiation in a natural task. Anim Cogn 4:347–361CrossRefGoogle Scholar
  18. Byrne RW, Barnard PJ, Davidson I, Janik VM, McGrew WC, Miklósi Á, Wiessner P (2004) Understanding culture across species. Trends Cogn Sci 8:341–346PubMedCrossRefGoogle Scholar
  19. Caldwell CA, Millen AE (2009) Social learning mechanisms and cumulative cultural evolution: is imitation necessary? Psychol Sci 20:1478–1483PubMedCrossRefGoogle Scholar
  20. Connolly K, Elliott JM (1972) The evolution and ontogeny of hand function. In: Blurton-Jones N (ed) Ethological studies of child behaviour. Cambridge University Press, Cambridge, pp 329–383Google Scholar
  21. Corp N, Byrne RW (2002) The ontogeny of manual skill in wild chimpanzees: evidence from feeding on the fruit of Saba florida. Behaviour 139:137–168CrossRefGoogle Scholar
  22. Custance D, Whiten A, Fredman T (1999) Social learning of an artificial fruit task in capuchin monkeys (Cebus apella). J Comp Psychol 113:13–23CrossRefGoogle Scholar
  23. de Waal FBM (1998) No imitation without identification. Behav Brain Sci 21:689CrossRefGoogle Scholar
  24. Fox E, Sitompul A, Van Schaik CP (1999) Intelligent tool use in wild Sumatran orangutans. In: Parker ST, Miles HL, Mitchell RW (eds) The mentality of gorillas and orangutans. Cambridge University Press, Cambridge, pp 99–116CrossRefGoogle Scholar
  25. Galef BG (2003) “Traditional” foraging behaviours of brown and black rats (Rattus norwegicus and Rattus rattus). In: Fragaszy DM, Perry S (eds) The biology of traditions: models and evidence. Cambridge University Press, Cambridge, pp 159–186CrossRefGoogle Scholar
  26. Hobaiter C, Byrne RW (2010) Able-bodied wild chimpanzees imitate a motor procedure used by a disabled individual to overcome handicap. PLoS One 5:e11959PubMedCrossRefGoogle Scholar
  27. Hoppitt WJE, Laland KN (2008) Social processes influencing learning in animals: a review of the evidence. Adv Study Behav 38:105–165CrossRefGoogle Scholar
  28. Humle T, Matsuzawa T (2002) Ant dipping among the chimpanzees of Bossou, Guinea, and some comparisons with other sites. Am J Phys Anthropol 58:133–148Google Scholar
  29. Laland KN, Janik V (2006) The animal cultures debate. Trends Evol Ecol 21:542–547CrossRefGoogle Scholar
  30. Langergraber KE, Boesch C, Inoue E, Inoue-Murayama M, Mitani JC, Nishida T, Pusey AE, Reynolds V, Schubert G, Wrangham RW, Wroblewski E, Vigilant L (2010) Genetic and ‘cultural’ similarity in wild chimpanzees. Proc R Soc B doi: 10.1098/rspb.2010.1112
  31. McGrew WC (1974) Tool use by wild chimpanzees feeding on driver ants. J Hum Evol 3:501–508CrossRefGoogle Scholar
  32. McGrew WC (1992) Chimpanzee material culture: implications for human evolution. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  33. McGrew WC, Ham RM, White L, Tutin CG, Fernandez M (1997) Why don’t chimpanzees in Gabon crack nuts? Int J Primatol 18:353–374CrossRefGoogle Scholar
  34. Mobius Y, Boesch C, Koops K, Matsuzawa T, Humle T (2008) Cultural differences in army ant predation by West African chimpanzees? A comparative study of microecological variables. Anim Behav 76:37–45CrossRefGoogle Scholar
  35. Sawyer SC, Robbins MM (2009) A novel food processing technique by a wild mountain gorilla (Gorilla beringei beringei). Folia Primatol 80:83–88PubMedCrossRefGoogle Scholar
  36. Stafford DK, Milliken GW, Ward JP (1993) Patterns of hand and mouth lateral biases in bamboo leaf shoot feeding and simple food reaching in the gentle lemur (Hapalemur griseus). Am J Primatol 29:195–207CrossRefGoogle Scholar
  37. Stoinski TS, Wrate JL, Ure N, Whiten A (2001) Imitative learning by captive western lowland gorillas (Gorilla gorilla gorilla) in a simulated food-processing task. J Comp Psychol 115:272–281PubMedCrossRefGoogle Scholar
  38. Stokes EJ, Quiatt D, Reynolds V (1999) Snare injuries to chimpanzees (Pan troglodytes) at 10 study sites in East and West Africa. Am J Primatol 49:104–105Google Scholar
  39. Tennie C, Hedwig D, Call J, Tomasello M (2008) An experimental study of nettle feeding in captive gorillas. Am J Primatol 70:584–593PubMedCrossRefGoogle Scholar
  40. Tennie C, Call J, Tomasello M (2009) Great ape traditions and zones of latent solutions. St Andrews, ScotlandGoogle Scholar
  41. Tomasello M (1998) Emulation learning and cultural learning. Behav Brain Sci 21:703–704CrossRefGoogle Scholar
  42. van Schaik CP, Ancrenaz M, Borgen G, Galdikas B, Knott CD, Singleton I, Suzuki A, Utami SS, Merrill M (2003) Orangutan cultures and the evolution of material culture. Science 299:102–105PubMedCrossRefGoogle Scholar
  43. Vereijken B, Whiting HTA (1998) Hoist by their own petard: the constraints of hierarchical models. Behav Brain Sci 21:705CrossRefGoogle Scholar
  44. Whiten A (2005) The second inheritance system of chimpanzees and humans. Nature 437:52–55PubMedCrossRefGoogle Scholar
  45. Whiten A, Goodall J, McGrew WC, Nishida T, Reynolds V, Sugiyama Y, Tutin CEG, Wrangham RW, Boesch C (1999) Cultures in chimpanzees. Nature 399:682–685PubMedCrossRefGoogle Scholar
  46. Whiten A, Goodall J, McGrew WC, Nishida T, Reynolds V, Sugiyama Y, Tutin CEG, Wrangham RW, Boesch C (2001) Charting cultural variation in chimpanzees. Behaviour 138:1481–1516CrossRefGoogle Scholar
  47. Whiten A, Horner V, de Waal FBM (2005) Conformity to cultural norms of tool use in chimpanzees. Nature 437:737–740PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Richard W. Byrne
    • 1
    Email author
  • Catherine Hobaiter
    • 1
  • Michelle Klailova
    • 2
  1. 1.Centre for Social Learning and Cognitive Evolution and Scottish Primate Research Group, School of PsychologyUniversity of St AndrewsSt AndrewsScotland, UK
  2. 2.Scottish Primate Research Group, Department of PsychologyUniversity of StirlingStirlingScotland, UK

Personalised recommendations