Eastern water dragons use alternative social tactics at different local densities

  • Kasha Strickland
  • Eric M Patterson
  • Céline H Frère
Original Article


Animals’ affiliative behaviour is, in many species, driven by population density. Although the causes of such an effect are probably varied, affiliative social behaviour can sometimes be used to minimise conflict and competition when conspecific density is high. However, individuals might instead use multiple different social tactics (e.g. social avoidance or social preference) in order to optimally minimise competition and social conflict at different local densities. Here, we investigated whether eastern water dragons (Intellegama lesueurii) use alternative social tactics at different local densities. Interestingly, we found that whilst the number of casual associations per individual increased linearly with density, as predicted by our null expectation, the relationship with density differed between social avoidance and social preference. In particular, individuals had more preferential associations at intermediate density but more avoidances at high density. This suggests that both male and female dragons use alternative social tactics according to the density of their social environment, possibly to optimally reduce social conflict.

Significance statement

This study investigated the relationship between local density and social tactics (e.g. social preference and social avoidance) in eastern water dragons. We demonstrate that dragons use different social tactics according to local density. We therefore present evidence that dragons may use alternative social tactics to optimally reduce competition and conflict in their local environment.


Density Social behaviour Eastern water dragons Social conflict Social tactics Competition 



We would like to thank all staff at Roma St Parkland for their ongoing support and cooperation with data collection. We also thank all students and volunteers who have helped to collect data. Thanks also to two anonymous reviewers, as well as Damien Farine for constructive feedback and discussion on a previous version of this manuscript. This work was supported by Dr. Celine Frere’s USC Research Fellowship from University of the Sunshine Coast. This research was conducted with the approval of the University of the Sunshine Coast’s animal ethics committee (approval number AN/A/14/87).

Data accessibility

Data generated and analysed during this study are included in this published article (and its supplementary information files). All R code used to generate null model can be found at (Strickland et al. 2017), and R code used to analyse and plot data is included in the supplementary material.

Author contributions

KS conceived the ideas with input from CF. KS and CF collected data. KS and EMP analysed data. KS wrote the manuscript, with input from all authors. All authors approved the final version of the manuscript for publication.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This work was supported by Dr. Celine Frere’s USC Research Fellowship from the University of the Sunshine Coast. Authors have no conflict of interest to declare. This research was conducted with the approval of the University of the Sunshine Coast’s animal ethics committee (approval number AN/A/14/87). All authors give consent for the publication of this article.

Supplementary material

265_2018_2563_MOESM1_ESM.pdf (502 kb)
ESM 1 (PDF 502 kb)
265_2018_2563_MOESM2_ESM.xlsx (21 kb)
ESM 2 (XLSX 21 kb)


  1. Albon SD, Staines HJ, Guinness FE, Clutton-Brock TH (1992) Density-dependent changes in the spacing behaviour of female kin in red deer. J Anim Ecol 61:131–137CrossRefGoogle Scholar
  2. Aplin L, Farine D, Morand-Ferron J, Cole E, Cockburn A, Sheldon B (2013) Individual personalities predict social behaviour in wild networks of great tits (Parus major). Ecol Lett 16:1365–1372CrossRefPubMedGoogle Scholar
  3. Aureli F, Schaffner CM, Boesch C, Bearder SK, Call J, Chapman CA, Connor R, Di Fiore A, Dunbar RIM, Henzi SP (2008) Fission-fusion dynamics. Curr Anthropol 49:627–654Google Scholar
  4. Aureli F, van Panthaleon van Eck CJ, Veenema HC (1995) Long-tailed macaques avoid conflicts during short-term crowding. Aggressive Behav 21:113–122CrossRefGoogle Scholar
  5. Baan C, Bergmüller R, Smith DW, Molnar B (2014) Conflict management in free-ranging wolves, Canis lupus. Anim Behav 90:327–334CrossRefGoogle Scholar
  6. Baird TA, Baird TD, Shine R (2012) Aggressive transition between alternative male social tactics in a long-lived Australian dragon (Physignathus lesueurii) living at high density. PLoS One 7:e41819CrossRefPubMedPubMedCentralGoogle Scholar
  7. Balshine S, Wong MYL, Reddon AR (2017) Social motivation and conflict resolution tactics as potential building blocks of sociality in cichlid fishes. Behav Process 141:152–160CrossRefGoogle Scholar
  8. Bates D, Maechler M, Bolker B, Walker S (2014) lme4: linear mixed-effects models using Eigen and S4. R package version 1,
  9. Best EC, Dwyer RG, Seddon JM, Goldizen AW (2014) Associations are more strongly correlated with space use than kinship in female eastern grey kangaroos. Anim Behav 89:1–10CrossRefGoogle Scholar
  10. Calenge C (2006) The package “adehabitat” for the R software: a tool for the analysis of space and habitat use by animals. Ecol Model 197:516–519CrossRefGoogle Scholar
  11. Cant MA, Johnstone RA (2009) How threats influence the evolutionary resolution of within-group conflict. Am Nat 173:759–771CrossRefPubMedGoogle Scholar
  12. Carr GM, Macdonald DW (1986) The sociality of solitary foragers: a model based on resource dispersion. Anim Behav 34:1540–1549CrossRefGoogle Scholar
  13. Carter A, Macdonald S, Thomson V, Goldizen A (2009) Structured association patterns and their energetic benefits in female eastern grey kangaroos, Macropus giganteus. Anim Behav 77:839–846CrossRefGoogle Scholar
  14. Carter KD, Seddon JM, Frère CH, Carter JK, Goldizen AW (2013) Fission–fusion dynamics in wild giraffes may be driven by kinship, spatial overlap and individual social preferences. Anim Behav 85:385–394CrossRefGoogle Scholar
  15. Clutton-Brock T (2009) Cooperation between non-kin in animal societies. Nature 462:51–57CrossRefPubMedGoogle Scholar
  16. Clutton-Brock T, Huchard E (2013a) Social competition and its consequences in female mammals. J Zool 289:151–171CrossRefGoogle Scholar
  17. Clutton-Brock TH, Huchard E (2013b) Social competition and selection in males and females. Phil Trans R Soc B 368:20130074CrossRefPubMedGoogle Scholar
  18. Connor RC, Wells R, Mann J, Read A (2000) The bottlenose dolphin: social relationships in a fission-fusion society. In: Mann J, Connor R, Tyack P, Whitehead H (eds) Cetacean societies: field studies of whales and dolphins. University of Chicago Press, London, pp 91–126Google Scholar
  19. Cote J, Clobert J (2007) Social personalities influence natal dispersal in a lizard. Proc R Soc Lond B 274:383–390CrossRefGoogle Scholar
  20. Dwyer R, Best E, Goldizen A (2013) Digiroo2: an application programming interface for generating null models of social contact based on individuals' space use. R package version 0.5,
  21. Elgar MA (1989) Predator vigilance and group size in mammals and birds: a critical review of the empirical evidence. Biol Rev 64:13–33CrossRefPubMedGoogle Scholar
  22. Emlen ST, Lewis WO (1977) Ecology, sexual selection, and the evolution of mating systems. Science 197:215–223CrossRefPubMedGoogle Scholar
  23. Farine DR (2015) Proximity as a proxy for interactions: issues of scale in social network analysis. Anim Behav 104:e1–e5CrossRefGoogle Scholar
  24. Frère C, Chandrasoma D, Whiting M (2015) Polyandry in dragon lizards: inbred paternal genotypes sire fewer offspring. Ecol Evol 5:1686–1692CrossRefPubMedPubMedCentralGoogle Scholar
  25. Gardiner RZ, Doran E, Strickland K, Carpenter-Bundhoo L, Frère C (2014) A face in the crowd: a non-invasive and cost effective photo-identification methodology to understand the fine scale movement of eastern water dragons. PLoS One 9:e96992CrossRefPubMedPubMedCentralGoogle Scholar
  26. Hamilton WD (1964) The genetical evolution of social behaviour. I. J Theor Biol 7:1–16CrossRefPubMedGoogle Scholar
  27. Hofmann HA, Beery AK, Blumstein DT et al (2014) An evolutionary framework for studying mechanisms of social behavior. Trends Ecol Evol 29:581–589CrossRefPubMedGoogle Scholar
  28. Hubalek Z (1982) Coefficients of association and similarity, based on binary (presence-absence) data: an evaluation. Biol Rev 57:669–689CrossRefGoogle Scholar
  29. Huchard E, English S, Bell MB, Thavarajah N, Clutton-Brock T (2016) Competitive growth in a cooperative mammal. Nature 533:532–534CrossRefPubMedPubMedCentralGoogle Scholar
  30. Jannett FJ (1978) The density-dependent formation of extended maternal families of the montane vole, Microtus montanus nanus. Behav Ecol Sociobiol 3:245–263CrossRefGoogle Scholar
  31. Jirotkul M (1999) Population density influences male–male competition in guppies. Anim Behav 58:1169–1175CrossRefPubMedGoogle Scholar
  32. Judge PG, de Waal FBM (1993) Conflict avoidance among rhesus monkeys: coping with short-term crowding. Anim Behav 46:221–232CrossRefGoogle Scholar
  33. Komers PE (1997) Behavioural plasticity in variable environments. Can J Zool 75:161–169CrossRefGoogle Scholar
  34. Korb J, Foster KR (2010) Ecological competition favours cooperation in termite societies. Ecol Lett 13:754–760CrossRefPubMedGoogle Scholar
  35. Koski SE, Burkart JM (2015) Common marmosets show social plasticity and group-level similarity in personality. Sci Rep 5:8878CrossRefPubMedPubMedCentralGoogle Scholar
  36. Kutsukake N, Clutton-Brock TH (2008) Do meerkats engage in conflict management following aggression? Reconciliation, submission and avoidance. Anim Behav 75:1441–1453CrossRefGoogle Scholar
  37. Le Galliard JF, Paquet M, Mugabo M (2015) An experimental test of density-dependent selection on temperament traits of activity, boldness and sociability. J Evol Biol 28:1144–1155CrossRefPubMedGoogle Scholar
  38. Littleford-Colquhoun BL, Clemente C, Whiting MJ, Ortiz-Barrientos D, Frère CH (2017) Archipelagos of the Anthropocene: rapid and extensive differentiation of native terrestrial vertebrates in a single metropolis. Mol Ecol 26:2466–2481CrossRefPubMedGoogle Scholar
  39. Montiglio P-O, McGlothlin JW, Farine DR (2017) Social structure modulates the evolutionary consequences of social plasticity: a social network perspective on interacting phenotypes. Ecol Evol 8:1451–1464CrossRefPubMedPubMedCentralGoogle Scholar
  40. Myers K, Hale CS, Mykytowycz R, Hughes RL (1971) The effects of varying density and space on sociality and health in animals. In: Esser AH (ed) Behavior and environment: the use of space by animals and men. Springer US, Boston, MA, pp 148–187CrossRefGoogle Scholar
  41. Packer C, Pusey AE (1982) Cooperation and competition within coalitions of male lions: kin selection or game theory? Nature 296:740–742CrossRefGoogle Scholar
  42. Port M, Schülke O, Ostner J (2017) From individual to group territoriality: competitive environments promote the evolution of sociality. Am Nat 189:E46–E57CrossRefPubMedGoogle Scholar
  43. R Development Core Team (2010) R: a language and environment for statistical computing. In. R Foundation for Statistical Computing, Vienna, Austria,
  44. Riley JL, Noble DWA, Byrne RW, Whiting MJ (2017) Early social environment influences the behaviour of a family-living lizard. Roy Soc open sci 4:161082CrossRefGoogle Scholar
  45. Ruppert D (2002) Selecting the number of knots for penalized splines. J Comput Graph Stat 11:735–757CrossRefGoogle Scholar
  46. Schoepf I, Schradin C (2012) Better off alone! Reproductive competition and ecological constraints determine sociality in the African striped mouse (Rhabdomys pumilio). J Anim Ecol 81:649–656CrossRefPubMedGoogle Scholar
  47. Schradin C (2013) Intraspecific variation in social organization by genetic variation, developmental plasticity, social flexibility or entirely extrinsic factors. Phil Trans R Soc B 368:20120346CrossRefPubMedGoogle Scholar
  48. Schradin C, König B, Pillay N (2010) Reproductive competition favours solitary living while ecological constraints impose group-living in African striped mice. J Anim Ecol 79:515–521CrossRefPubMedGoogle Scholar
  49. Schradin C, Pillay N (2005) Intraspecific variation in the spatial and social organization of the African striped mouse. J Mammal 86:99–107CrossRefGoogle Scholar
  50. Schülke O, Bhagavatula J, Vigilant L, Ostner J (2010) Social bonds enhance reproductive success in male macaques. Curr Biol 20:2207–2210CrossRefPubMedGoogle Scholar
  51. Snell-Rood EC (2013) An overview of the evolutionary causes and consequences of behavioural plasticity. Anim Behav 85:1004–1011CrossRefGoogle Scholar
  52. Sommer V, Denham A, Little K (2002) Postconflict behaviour of wild Indian langur monkeys: avoidance of opponents but rarely affinity. Anim Behav 63:637–648CrossRefGoogle Scholar
  53. Spiegel O, Leu ST, Sih A, Bull CM (2016) Socially interacting or indifferent neighbours? Randomization of movement paths to tease apart social preference and spatial constraints. Methods Ecol Evol 7:971–979CrossRefGoogle Scholar
  54. Stacey PB, Bock CE (1978) Social plasticity in the acorn woodpecker. Science 202:1298–1300CrossRefPubMedGoogle Scholar
  55. Strickland K, Frère CH (2017) Predictable males and unpredictable females: repeatability of sociability in eastern water dragons. Behav Ecol 29:236–243CrossRefGoogle Scholar
  56. Strickland K, Gardiner R, Schultz AJ, Frère CH (2014) The social life of eastern water dragons: sex differences, spatial overlap and genetic relatedness. Anim Behav 97:53–61CrossRefGoogle Scholar
  57. Strickland K, Levengood A, Foroughirad V, Mann J, Krzyszczyk E, Frère CH (2017) A framework for the identification of long-term social avoidance in longitudinal datasets. R Soc open sci 4:170641CrossRefPubMedPubMedCentralGoogle Scholar
  58. Symonds MRE, Moussalli A (2011) A brief guide to model selection, multimodel inference and model averaging in behavioural ecology using Akaike’s information criterion. Behav Ecol Sociobiol 65:13–21CrossRefGoogle Scholar
  59. Thompson M (1993) Estimate of the population structure of the eastern water dragon, Physignathus lesueurii (Reptilia: Agamidae), along riverside habitat. Wildlife Res 20:613–619CrossRefGoogle Scholar
  60. van Schaik CP (1999) The socioecology of fission-fusion sociality in orangutans. Primates 40:69–86CrossRefPubMedGoogle Scholar
  61. van Tienhoven AM, Den Hartog JE, Reijns RA, Peddemors VM (2007) A computer-aided program for pattern-matching of natural marks on the spotted raggedtooth shark Carcharias taurus. J Appl Ecol 44:273–280CrossRefGoogle Scholar
  62. Vander Wal E, Laforge MP, McLoughlin PD (2014) Density dependence in social behaviour: home range overlap and density interacts to affect conspecific encounter rates in a gregarious ungulate. Behav Ecol Sociobiol 68:383–390CrossRefGoogle Scholar
  63. Ward A, Webster M (2016) Sociality: the behaviour of group-living animals. Springer International Publishing, ChamCrossRefGoogle Scholar
  64. Whitehead H (2008) Analyzing animal societies: quantitative methods for vertebrate social analysis. University of Chicago Press, ChicagoCrossRefGoogle Scholar
  65. Wood S (2000) Modelling and smoothing parameter estimation with multiple quadratic penalties. J Roy Stat Soc 62:413–428CrossRefGoogle Scholar
  66. Wood S (2006) An introduction to generalized additive models with R. Chapman and Hall, Boca RatonCrossRefGoogle Scholar
  67. Zhang P, Li B-g, Qi X-g, MacIntosh AJJ, Watanabe K (2012) A proximity-based social network of a group of Sichuan snub-nosed monkeys (Rhinopithecus roxellana). Int J Primatol 33:1081–1095CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Genecology Research CentreUniversity of the Sunshine CoastMaroochydore DCAustralia
  2. 2.Department of Biology and PsychologyGeorgetown UniversityWashingtonUSA
  3. 3.Office of Protected Resources, National Marine Fisheries Service, National Oceanic and Atmospheric AdministrationSilver SpringUSA

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