Behavioral Ecology and Sociobiology

, Volume 63, Issue 7, pp 1067–1077 | Cite as

The emergence of unshared consensus decisions in bottlenose dolphins

  • David Lusseau
  • Larissa Conradt
Original Paper


Unshared consensus decision-making processes, in which one or a small number of individuals make the decision for the rest of a group, are rarely documented. However, this mechanism can be beneficial for all group members when one individual has greater knowledge about the benefits of the decision than other group members. Such decisions are reached during certain activity shifts within the population of bottlenose dolphins residing in Doubtful Sound, New Zealand. Behavioral signals are performed by one individual and seem to precipitate shifts in the behavior of the entire group: males perform side flops and initiate traveling bouts while females perform upside-down lobtails and terminate traveling bouts. However, these signals are not observed at all activity shifts. We find that, while side flops were performed by males that have greater knowledge than other male group members, this was not the case for females performing upside-down lobtails. The reason for this could have been that a generally high knowledge about the optimal timing of travel terminations rendered it less important which individual female made the decision.


Behavioral ecology Decision-making process Bottlenose dolphin Group living 



DL was supported by a Killam Postdoctoral fellowship provided by the Killam Trusts. LC is supported by a Royal Society University Research fellowship. We would like to thank Hal Whitehead for numerous fruitful discussions and suggestions, Shane Gero for suggestions on earlier drafts, and three anonymous reviewers. Data collection and compilation was funded by the New Zealand Whale and Dolphin Trust, the New Zealand Department of Conservation, Real Journeys Ltd, and the University of Otago (Departments of Zoology and Marine Sciences and Bridging Grant scheme). We would also like to thank Susan M. Lusseau, Oliver J. Boisseau, Liz Slooten, and Steve Dawson for their numerous contributions to this research.


  1. Altmann J (1974) Observational study of behaviour: sampling methods. Behaviour 49:227–267PubMedCrossRefGoogle Scholar
  2. Ay N, Flack JC, Krakauer DC (2007) Robustness and complexity co-constructed in multimodal signalling networks. Philos Trans R Soc Lond B 362:441–447CrossRefGoogle Scholar
  3. Baird RW, Dill LM (1996) Ecological and social determinants of group size in transient killer whales. Behav Ecol 7:408–416CrossRefGoogle Scholar
  4. Barclay (1982) Interindividual use of echolocation calls: eavesdropping by bats. Behav Ecol Sociobiol 10:271–275CrossRefGoogle Scholar
  5. Blundell GM, Ben-David M, Bowyer RT (2002) Sociality in river otters: cooperative foraging or reproductive strategies? Behav Ecol 13:134–141CrossRefGoogle Scholar
  6. Boisseau OJ (2004) The acoustic behaviour of resident bottlenose dolphins in Fiordland, New Zealand. Department of Marine Sciences, University of Otago, Dunedin, p 320Google Scholar
  7. Boisseau OJ (2005) Quantifying the acoustic repertoire of a population: the vocalizations of free-ranging bottlenose dolphins in Fiordland, New Zealand. J Acoust Soc Am 117:2318–2329PubMedCrossRefGoogle Scholar
  8. Boyko AR, Gibson RM, Lucas JR (2004) How predation risk affects the temporal dynamics of avian leks: greater sage grouse versus golden eagles. Am Nat 163:154–165PubMedCrossRefGoogle Scholar
  9. Bradbury JW, Vehrencamp SL (2000) Economic models of animal communication. Anim Behav 59:259–268PubMedCrossRefGoogle Scholar
  10. Cairns JS, Schwager SJ (1987) A comparison of association indices. Anim Behav 35:1454–1469CrossRefGoogle Scholar
  11. Connor RC, Heithaus MR, Barre LM (2001) Complex social structure, alliance stability and mating access in a bottlenose dolphin ‘super-alliance’. Proc R Soc Lond B 268:263–267CrossRefGoogle Scholar
  12. Conradt L, Roper TJ (2000) Activity synchrony and social cohesion: a fission–fusion model. Proc R Soc Lond B-Biol Sci 267:2213–2218CrossRefGoogle Scholar
  13. Conradt L, Roper TJ (2003) Group decision-making in animals. Nature 421:155–158PubMedCrossRefGoogle Scholar
  14. Conradt L, Roper TJ (2005) Consensus decision making in animals. Trends Ecol Evol 20:449–456PubMedCrossRefGoogle Scholar
  15. Couzin ID, Krause J, Franks NR, Levin SA (2005) Effective leadership and decision-making in animal groups on the move. Nature 433:513–516PubMedCrossRefGoogle Scholar
  16. Currey RJC, Dawson SM, Slooten E (2007) New abundance estimates suggest Doubtful Sound bottlenose dolphins are declining. Pacific Conservation Biology 13:265–273Google Scholar
  17. Dawson SM (1991) Clicks and communication: the behavioural and social contexts of Hector's dolphin vocalizations. Ethology 88:265–276CrossRefGoogle Scholar
  18. Eguiluz VM, Zimmermann MG, Cela-Conde CJ, San Miguel M (2005) Cooperation and emergence of role differentiation in the dynamics of social networks. Am J Soc 110:977–1008CrossRefGoogle Scholar
  19. Flack JC, Girvan M, de Waal FBM, Krakauer DC (2006) Policing stabilizes construction of social niches in primates. Nature 439:426–429PubMedCrossRefGoogle Scholar
  20. Fritz H, de Garine Wichatitsky M (1996) Foraging in a social antelope: effects of group size on foraging choices and resource perception in impala. J Anim Ecol 65:736–742CrossRefGoogle Scholar
  21. Götz T, Verfuss UK, Schnitzler HU (2006) ‘Eavesdropping’ in wild rough-toothed dolphins (Steno bredanensis)? Biol Lett 2:5–7PubMedCrossRefGoogle Scholar
  22. Heard DC (1992) The effect of wolf predation and snow cover on musk-ox group-size. Am Nat 139:190–204CrossRefGoogle Scholar
  23. Jakob EM (2004) Individual decisions and group dynamics: why pholcid spiders join and leave groups. Anim Behav 68:9–20CrossRefGoogle Scholar
  24. Krause J, Lusseau D, James R (2009) Animal social networks: an introduction. Behav Ecol Sociobiol. doi: 10.1007/s00265-009-0747-0
  25. List C (2004) Democracy in animal groups: a political science perspective. Trends Ecol Evol 19:168–169PubMedCrossRefGoogle Scholar
  26. Lusseau D (2003) Male and female bottlenose dolphins Tursiops sp. have different strategies to avoid interactions with tour boats in Doubtful Sound, New Zealand. Mar Ecol-Prog Ser 257:267–274CrossRefGoogle Scholar
  27. Lusseau D (2006) Why do dolphins jump? Interpreting the behavioural repertoire of bottlenose dolphins (Tursiops sp.) in Doubtful Sound, New Zealand. Behav Processes 73:257–265PubMedCrossRefGoogle Scholar
  28. Lusseau D (2007a) Evidence for social role in a dolphin social network. Evol Ecol 21:351–366CrossRefGoogle Scholar
  29. Lusseau D (2007b) Why are male social relationships complex in the Doubtful Sound bottlenose dolphin population? PLoS ONE 2:e348PubMedCrossRefGoogle Scholar
  30. Lusseau D, Higham JES (2004) Managing the impacts of dolphin-based tourism through the definition of critical habitats: the case of bottlenose dolphins (Tursiops spp.) in Doubtful Sound, New Zealand. Tour Manage 25:657–667CrossRefGoogle Scholar
  31. Lusseau D, Newman MEJ (2004) Identifying the role that animals play in their social networks. Proc R Soc Lond B 271:S477–S481CrossRefGoogle Scholar
  32. Lusseau D, Schneider K, Boisseau OJ, Haase P, Slooten E, Dawson SM (2003) The bottlenose dolphin community of Doubtful Sound features a large proportion of long-lasting associations—can geographic isolation explain this unique trait? Behav Ecol Sociobiol 54:396–405CrossRefGoogle Scholar
  33. Lusseau D, Williams RJ, Wilson B, Grellier K, Barton TR, Hammond PS, Thompson PM (2004) Parallel influence of climate on the behaviour of Pacific killer whales and Atlantic bottlenose dolphins. Ecol Lett 7:1068–1076CrossRefGoogle Scholar
  34. Lusseau D, Whitehead H, Gero S (2008) Incorporating uncertainty into the study of animal social networks. Anim Behav 75:1809–1815CrossRefGoogle Scholar
  35. Lusseau SM, Wing SR (2006) Importance of local production versus pelagic subsidies in the diet of an isolated population of bottlenose dolphins Tursiops sp. Mar Ecol Prog Ser 321:283–293CrossRefGoogle Scholar
  36. Mann J (2000) Unraveling the dynamics of social life: long-term studies and observational methods. In: Mann J, Connor RC, Tyack PL, Whitehead H (eds) Cetacean societies. University of Chicago Press, London, pp 45–64Google Scholar
  37. Monni S, Li HZ (2008) Vertex clustering in random graphs via reversible jump Markov chain Monte Carlo. J Comput Graph Stat 17:388–409CrossRefGoogle Scholar
  38. Newman MEJ (2003) The structure and function of complex networks. SIAM Review 45:167–256CrossRefGoogle Scholar
  39. Newman MEJ (2004) Fast algorithm for detecting community structure in networks. Phys Rev E 69:066133CrossRefGoogle Scholar
  40. Newman MEJ (2006a) Finding community structure in networks using eigenvectors of matrices. Physics Review E 74 (2006), p. 036104Google Scholar
  41. Newman MEJ (2006a) Modularity and community structure in networks. Proc Nat Acad Sci USA 103:8577–8582PubMedCrossRefGoogle Scholar
  42. Newman MEJ, Girvan M (2004) Finding and evaluating community structure in networks. Phys Rev E 69:art026113Google Scholar
  43. Noe R, Bshary R (1997) The formation of red colobus-diana monkey associations under predation pressure from chimpanzees. Proc R Soc Lond B-Biol Sci 264:253–259CrossRefGoogle Scholar
  44. Norris KS (1994) The Hawaiian spinner dolphin. University of California Press, BerkeleyGoogle Scholar
  45. Quinn GP, Keough MJ (2002) Experimental design and data analysis for biologists. Cambridge University Press, Cambridge, UKGoogle Scholar
  46. Rodgers KL, Wing SR (2008) Spatial structure and movement of blue cod in Doubtful Sound, New Zealand, inferred from delta C-13 and delta N-15. Mar Ecol Prog Ser 359:239–248CrossRefGoogle Scholar
  47. Rosvall M, Bergstrom CT (2007) An information-theoretic framework for resolving community structure in complex networks. Proc Nat Acad Sci USA 104:7327–7331PubMedCrossRefGoogle Scholar
  48. Ruckstuhl KE (1999) To synchronise or not to synchronise: a dilemma for young bighorn males. Behaviour 136:805–818CrossRefGoogle Scholar
  49. Ruckstuhl KE, Neuhaus P (2002) Sexual segregation in ungulates: a comparative test of three hypotheses. Biol Rev Camb Philos Soc 77:77–96PubMedGoogle Scholar
  50. Schneider K (1999) Behaviour and ecology of bottlenose dolphins in Doubtful Sound, Fiordland, New Zealand. Marine Sciences, University of Otago, Dunedin, p 200Google Scholar
  51. Seppänen J-T, Forsman J-T, Mönkkönen M, Thomson RL (2007) Social information use is a process across time, space and ecology, reaching heterospecifics. Ecology 88:1622–1633PubMedCrossRefGoogle Scholar
  52. Templeton JJ, Giraldeau LA (1996) Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment. Behav Ecol Sociobiol 38:105–114CrossRefGoogle Scholar
  53. Whitehead H (2009) SOCPROG programs: analyzing animal social structures. Behav Ecol Sociobiol. doi: 10.1007/s00265-008-0697-y
  54. Whitehead H, Dufault S (1999) Techniques for analyzing vertebrate social structure using identified individuals: review and recommendations. Adv Study Behav 28:33–74CrossRefGoogle Scholar
  55. Williams JA, Dawson SM, Slooten E (1993) The abundance and distribution of bottle-nosed dolphins (Tursiops truncatus) in Doubtful Sound, New Zealand. Can J Zool 71:2080–2088CrossRefGoogle Scholar
  56. Würsig B, Würsig M (1977) The photographic determination of group size, composition, and stability of coastal porpoises (Tursiops truncatus). Science 198:755–756CrossRefGoogle Scholar
  57. Yamagiwa J, Kahekwa J, Basabose AK (2003) Intra-specific variation in social organization of gorillas: implications for their social evolution. Primates 44:359–369PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Institute of Biological and Environmental SciencesUniversity of AberdeenAberdeenUK
  2. 2.Department of Biology and Environmental ScienceUniversity of SussexBrightonUK

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