Skip to main content
SpringerLink
Log in

Potentially infanticidal behavior in the Amazon river dolphin (Inia geoffrensis)

  • Short Communication
  • Published:
acta ethologica Aims and scope Submit manuscript

Abstract

Infanticide by males is a phenomenon common in species in which the reproductive output of large numbers of females can be monopolized by a small number of males. It is thought to increase a male’s fitness, at the expense of the fitness of the infant’s parents, by bringing females into season more quickly. Infanticide by males has been recorded in just three cetacean species. We report aggressive behavior suggestive of infanticide in a fourth, the Amazon river dolphin (Inia geoffrensis). We observed and photographed a series of attacks on a neonate Amazon river dolphin by a large male, with apparent protective behavior by the mother. Although infanticide was not confirmed, the forceful, aggressive behaviors were highly suggestive of infanticidal behavior and represent another important data point for comparative studies of infanticide in mammals. Amazon river dolphins may have a polygynous, polyandrous, or promiscuous mating system, the latter two of which are not the norm in species in which the reproductive output of large numbers of females are monopolized by a small number of males. However, sexual dimorphism, high rates of aggression by males, socio-sexual object-carrying displays by males, and a long interbirth interval suggest that successful male Amazon river dolphins may be able to monopolize a large proportion of mating opportunities, and it is plausible that male dolphins can improve their reproductive success by bringing females into estrous sooner by killing the offspring of other males.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

References

  • Best, R. C. & Da Silva, V. M. 1993. Inia geoffrensis. Mamm Species, 1–8

  • Bruno S, Politi E, Bearzi G (2004) Social organisation of a common dolphin community in the eastern Ionian Sea: evidence of a fluid fission-fusion society. Eur Res Cetac 15:49–51

    Google Scholar 

  • Díaz López B, López A, Methion S, Covelo P (2017) Infanticide attacks and associated epimeletic behaviour in free-ranging common bottlenose dolphins (Tursiops truncatus). J Mar Biol Assoc U K:1–9

  • Dunn DG, Barco SG, Pabst DA, Mclellan WA (2002) Evidence for infanticide in bottlenose dolphins of the Western North Atlantic. J Wildl Dis 38:505–510

    Article  PubMed  Google Scholar 

  • Gomez-Salazar C, Trujillo F, Whitehead H (2012) Ecological factors influencing group sizes of river dolphins (Inia geoffrensis and Sotalia fluviatilis). Mar Mamm Sci 28:E124–E142

    Article  Google Scholar 

  • Hrdy SB (1979) Infanticide among animals: a review, classification, and examination of the implications for the reproductive strategies of females. Ethol Sociobiol 1:13–40

    Article  Google Scholar 

  • Kaplan J, Lentell BJ, Lange W (2009) Possible evidence for infanticide among bottlenose dolphins (Tursiops truncatus) off St. Augustine, Florida. Mar Mamm Sci 25:970–975

    Article  Google Scholar 

  • Karczmarski L (1999) Group dynamics of humpback dolphins (Sousa chinensis) in the Algoa Bay region, South Africa. J Zool 249:283–293

    Article  Google Scholar 

  • Lukas D, Huchard E (2014) The evolution of infanticide by males in mammalian societies. Science 346:841–844

    Article  PubMed  CAS  Google Scholar 

  • Lunardi DG, Ferreira RG (2014) Fission-fusion dynamics of Guiana dolphin (Sotalia guianensis) groups at Pipa Bay, Rio Grande do Norte, Brazil. Mar Mamm Sci 30:1401–1416

    Article  Google Scholar 

  • Mann J, Connor RC, Barre LM, Heithaus MR (2000a) Female reproductive success in bottlenose dolphins (Tursiops sp.): life history, habitat, provisioning, and group-size effects. Behav Ecol 11:210–219

    Article  Google Scholar 

  • Mann, J., Connor, R. C., Tyack, P. & Whitehead, H. 2000b. The bottlenose dolphin: social relationships in a fission–fusion Q10 society. Cetac Soc: Field Stud Dolphins and Whales, 91–126

  • Mann J, Smuts B (1999) Behavioral development in wild bottlenose dolphin newborns (Tursiops sp.). Behaviour 136:529–566

    Article  Google Scholar 

  • Martin A, Da Silva V (2004) River dolphins and flooded forest: seasonal habitat use and sexual segregation of botos (Inia geoffrensis) in an extreme cetacean environment. J Zool 263:295–305

    Article  Google Scholar 

  • Martin A, Da Silva V (2006) Sexual dimorphism and body scarring in the boto (Amazon river dolphin) Inia geoffrensis. Mar Mamm Sci 22:25–33

    Article  Google Scholar 

  • Martin A, Da Silva V, Rothery P (2008) Object carrying as socio-sexual display in an aquatic mammal. Biol Lett 4:243–245

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  • Mcguire TL, Aliaga-Rossel ER (2007) Seasonality of reproduction in Amazon River dolphins (Inia geoffrensis) in three major river basins of South America. Biotropica 39:129–135

    Article  Google Scholar 

  • Mintzer VJ, Lorenzen K, Frazer TK, Silva VM, Martin AR (2016) Seasonal movements of river dolphins (Inia geoffrensis) in a protected Amazonian floodplain. Mar Mamm Sci 32:664–681

    Article  Google Scholar 

  • Nery MF, Simao SM (2009) Sexual coercion and aggression towards a newborn calf of marine tucuxi dolphins (Sotalia guianensis). Mar Mamm Sci 25:450–454

    Article  Google Scholar 

  • Norris, K. S., Wursig, B., Wells, R. S. & Wursig, M. 1994. The Hawaiian spinner dolphin, Univ of California Press

  • Parra GJ, Corkeron PJ, Arnold P (2011) Grouping and fission–fusion dynamics in Australian snubfin and Indo-Pacific humpback dolphins. Anim Behav 82:1423–1433

    Article  Google Scholar 

  • Patterson I, Reid R, Wilson B, Grellier K, Ross H, Thompson P (1998) Evidence for infanticide in bottlenose dolphins: an explanation for violent interactions with harbour porpoises? Proc Royal Soc London B: Biol Sci 265:1167–1170

    Article  CAS  Google Scholar 

  • Pearson HC (2009) Influences on dusky dolphin (Lagenorhynchus obscurus) fission-fusion dynamics in Admiralty Bay, New Zealand. Behav Ecol Sociobiol 63:1437–1446

    Article  Google Scholar 

  • Perrtree RM, Sayigh LS, Williford A, Bocconcelli A, Curran MC, Cox TM (2016) First observed wild birth and acoustic record of a possible infanticide attempt on a common bottlenose dolphin (Tursiops truncatus). Mar Mamm Sci 32:376–385

    Article  Google Scholar 

  • Shirihai, H., Jarrett, B. & Kirwan, G. M. 2006. Whales, dolphins, and other marine mammals of the world, Princeton University Press

  • Slooten E (1994) Behavior of Hector’s dolphin: classifying behavior by sequence analysis. J Mammal 75:956–964

    Article  Google Scholar 

  • Van Schaik, C. P., Pradhan, G. R. & Van Noordwijk, M. A. 2004. Mating conflict in primates: infanticide, sexual harassment and female sexuality. Sexual selection in primates: new and comparative perspectives. Cambridge University Press, Cambridge, 131–150

  • Zheng R, Karczmarski L, Lin W, Chan SC, Chang W-L, WU Y (2016) Infanticide in the Indo-Pacific humpback dolphin (Sousa chinensis). J Ethol 34:299–307

    Article  Google Scholar 

Download references

Acknowledgements

We thank Pam Bucur and the staff of Amazon Explorama Lodges for their assistance with logistics during our observations. We thank the editors and two anonymous reviewers for their detailed and helpful comments on our manuscript.

Author information

Authors and Affiliations

  1. The School for Field Studies, 100 Cummings Center, Beverly, MA, USA

    Mark T. Bowler

  2. San Diego Zoo Global Institute for Conservation Research, Escondido, CA, USA

    Mark T. Bowler

  3. Environmental Science and Policy, George Mason University, Fairfax, VA, USA

    Brian M. Griffiths

  4. School of Integrative Studies, George Mason University, Fairfax, VA, USA

    Michael P. Gilmore & Andrew Wingfield

  5. Psychology, School of Natural Sciences, University of Stirling, Stirling, UK

    Maribel Recharte

Authors
  1. Mark T. Bowler
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Brian M. Griffiths
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Michael P. Gilmore
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Andrew Wingfield
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Maribel Recharte
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Mark T. Bowler.

Ethics declarations

All applicable international, national, and institutional guidelines for the care and use of animals were followed.

Conflict of interest

The authors declare that they have no conflict of interest.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bowler, M.T., Griffiths, B.M., Gilmore, M.P. et al. Potentially infanticidal behavior in the Amazon river dolphin (Inia geoffrensis). acta ethol 21, 141–145 (2018). https://doi.org/10.1007/s10211-018-0290-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10211-018-0290-y

Keywords

Search

Navigation