Linking body mass and group dynamics in an obligate cooperative breeder

Arpat Ozgul*, Andrew W. Bateman, Sinead English, Tim Coulson, Tim H. Clutton-Brock

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

22 Citations (Scopus)


Social and environmental factors influence key life-history processes and population dynamics by affecting fitness-related phenotypic traits such as body mass. The role of body mass is particularly pronounced in cooperative breeders due to variation in social status and consequent variation in access to resources. Investigating the mechanisms underlying variation in body mass and its demographic consequences can help elucidate how social and environmental factors affect the dynamics of cooperatively breeding populations. In this study, we present an analysis of the effect of individual variation in body mass on the temporal dynamics of group size and structure of a cooperatively breeding mongoose, the Kalahari meerkat, Suricata suricatta. First, we investigate how body mass interacts with social (dominance status and number of helpers) and environmental (rainfall and season) factors to influence key life-history processes (survival, growth, emigration and reproduction) in female meerkats. Next, using an individual-based population model, we show that the models explicitly including individual variation in body mass predict group dynamics better than those ignoring this morphological trait. Body mass influences group dynamics mainly through its effects on helper emigration and dominant reproduction. Rainfall has a trait-mediated, destabilizing effect on group dynamics, whereas the number of helpers has a direct and stabilizing effect. Counteracting effects of number of helpers on different demographic rates, despite generating temporal fluctuations, stabilizes group dynamics in the long term. Our study demonstrates that social and environmental factors interact to produce individual variation in body mass and accounting for this variation helps to explain group dynamics in this cooperatively breeding population.

Original languageEnglish
Pages (from-to)1357-1366
Number of pages10
JournalJournal of Animal Ecology
Issue number6
Publication statusPublished - 1 Nov 2014


  • Body mass
  • Individual-based model
  • Morphological trait
  • Obligate cooperative breeder
  • Overview, design concepts, details (ODD) protocol
  • Population dynamics
  • Slender-tailed meerkat
  • Social group dynamics
  • Suricata suricatta
  • Trait-based demography

Fingerprint Dive into the research topics of 'Linking body mass and group dynamics in an obligate cooperative breeder'. Together they form a unique fingerprint.

  • Cite this