Sex and social status affect territorial defence in a cooperatively breeding cichlid fish, Neolamprologus savoryi
- 399 Downloads
Members of social groups must defend their shared territory against both predators and competitors. However, individuals differ widely in their contributions to territorial defence. Assessing the variation in response to territorial intrusions provides insight into both the benefits and costs of group living for different group members. In this study, we assessed the response of wild Neolamprologus savoryi to experimentally staged territorial intrusions. Neolamprologus savoryi is an understudied cooperatively breeding cichlid fish endemic to Lake Tanganyika, East Africa. We found that dominant male and dominant female N. savoryi were both highly aggressive towards heterospecific predators and towards same-sex conspecific rivals. Both dominant males and females were less aggressive towards opposite-sex conspecific opponents, with the relative reduction in aggression being most pronounced in males. Subordinates provided low levels of defence against all intruder types, which suggests that subordinate N. savoryi rely on larger group members for protection. Collectively, our results provide insight into the structure and function of N. savoryi social groups, and highlights key costs and benefits of cooperation for individual social group members.
KeywordsAggression Defence Cooperation Lake Tanganyika Neolamprologus pulcher
The authors wish to thank Danny Sinyinza, Dr. Cyprian Katongo, Dr. Harris Phiri, Peter Sekazway, Clement Sichamba, Augustine Mwewa, Celestine Mwewa, Fernandez Mwewa, Gegwin Kapembwe, Damius Kapembwe, and all of the wonderful staff of the Tanganyika Science Lodge for their logistical support of the field research. The research was supported by a Natural Sciences and Engineering Research Council of Canada Discovery (NSERC) grant and equipment grant to SB, as well as Ontario Innovation Trust and Canadian Foundation for Innovation awards to SB. Further funding for the field research was provided by a Journal of Experimental Biology Travelling Fellowship to CMO, and Canadian Society of Zoologists and McMaster School of Graduate Studies research grants to ARR. CMO was supported by the E.B. Eastburn Postdoctoral Fellowship from the Hamilton Community Foundation, and is currently supported by an NSERC Postdoctoral Fellowship. ARR was supported by the Margo Wilson and Martin Daly Ontario Graduate Scholarship, and is currently supported by the Richard H. Tomlinson Postdoctoral Fellowship, and an NSERC Postdoctoral Fellowship. IYL and JKH are supported by the Department of Evolution, Ecology, and Organismal Biology at The Ohio State University, The Ohio State University Fish Systematics Endowment, and the SciFund Challenge. JKH is supported by the American Academy of Underwater Sciences. SB is supported by the Canada Research Chair Program and the NSERC Discovery Program.
- Bates, D., M. Maechler, B. Bolker & S. Walker, 2013. lme4: Linear Mixed-Effects Models Using Eigen and S4. R package version 1.0-5. http://CRAN.R-project.org/package=lme4.
- Bolker, B. M., 2008. Ecological Models and Data in R. Princeton University Press, Princeton, NJ.Google Scholar
- Brichard, P., 1989. Cichlids and all the other fishes of Lake Tanganyika. THF Publications, Neptune City, NJ.Google Scholar
- De Rosario-Martinez, H., 2013. phia: Post-Hoc Interaction Analysis. R package version 0.1-5. http://CRAN.R-project.org/package=phia.
- Emlen, S. T., 1997. Predicting family dynamics in social vertebrates. In Krebs, J. R. & N. B. Davies (eds), Behavioural Ecology: An Evolutionary Approach. Wiley Publishers, Hoboken, NJ: 228–253.Google Scholar
- Godin, J.-G. J., 1997. Behavioural ecology of fishes: adaptations for survival and reproduction. In Godin, J.-G. J. (ed.), Behavioural Ecology of Teleost Fishes. Oxford University Press, Oxford, UK: 1–9.Google Scholar
- Kawanabe, H., M. Hori & M. Nagoshi, 1997. Fish Communities in Lake Tanganyika. Kyoto University Press, Kyoto, Japan.Google Scholar
- Kleiber, C. & A. Zeileis, 2008. AER: Applied Econometrics with R. R package version 1.2-2. http://CRAN.R-project.org/package=AER.
- Komdeur, J., 2006. Variation in individual investment strategies among social animals. Ethology 112: 729–747.Google Scholar
- Kondo, T., 1986. Feeding habits of Lamprologus savoryi (Teleostei: Cichlidae) with reference to its social behaviour. Physiology & Ecology Japan 23: 1–15.Google Scholar
- Konings, A., 1998. Tanganyika Cichlids in Their Natural Habitat. Cichlid Press, El Paso, TX.Google Scholar
- Konings, A., 2005. Back to Nature Guide to Tanganyika cichlids. Cichlid Press, El Paso, TX.Google Scholar
- Krause, J. & G. D. Ruxton, 2002. Living in Groups. Oxford University Press, Oxford, UK.Google Scholar
- McKaye, K. R. & B. A. Murry, 2008. Sex role differentiation in brood defense by a Nicaraguan cichlid fish, Amphilophus xiloanensis. Caribbean Journal of Science 44: 13–20.Google Scholar
- Nelson, J. S., 2006. Fishes of the World. Wiley Publishers, Hoboken, NJ.Google Scholar
- R Development Core Team, 2008. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org.
- Ripley, B., B. Venables, D. M. Bates, K. Hornik, A. Gebhardt & D. Firth, 2014. MASS: Support Functions and Datasets for Venables and Ripley’s MASS. R Package Version 7.3-31. http://CRAN.R-project.org/package=MASS.
- Sato, T. & M. M. Gashagaza, 1997. Shell-brooding cichlids of Lake Tanganyika: their habits and maing systems. In Kawanabe, H., M. Hori & M. Nagoshi (eds), Fish Communities in Lake Tanganyika. Kyoto University Press, Kyoto: 221–240.Google Scholar
- Sopinka, N. M., J. L. Fitzpatrick, J. K. Desjardins, K. A. Stiver, S. E. Marsh-Rollo & S. Balshine, 2009. Liver size reveals social status in the African cichlid Neolamprologus pulcher. Journal of Fish Biology 75: 1–16.Google Scholar
- Sturmbauer, C., W. Salzburger, N. Duftner, R. Schelly & S. Koblmüller, 2010. Evolutionary history of the Lake Tanganyika cichlid tribe Lamprologini (Teleostei: Perciformes) derived from mitochondrial and nuclear DNA data. Molecular Phylogenetics and Evolution 57: 266–284.CrossRefPubMedCentralPubMedGoogle Scholar
- Taborsky, M., 1987. Cooperative behaviour in fish: coalitions, kin groups and reciprocity. In Brown, J. L. & I. Kikkawa (eds), Animal Societies: Theories and Facts. Japan Scientific Society Press, Tokyo, Japan: 229–237.Google Scholar
- Trewavas, E. & M. Poll, 1952. Three new species and two new subspecies of the genus Lamprologus, cichlid fishes of Lake Tanganyika. Proceedings of the Royal Society of London B: Biological Sciences 116: 240–246.Google Scholar
- Zahavi, A. & A. Zahavi, 1997. The Handicap Principle: A Missing Piece of Darwin ‘s Puzzle. Oxford University Press, Oxford, UK.Google Scholar
- Zuur, A. F., J. M. Hilbe & E. N. Ieno, 2013. Beginner’s Guide to GLM and GLMM with R. Highland Statistics Ltd., Newburgh, UK.Google Scholar