, Volume 154, Issue 3, pp 561–570

Overdispersion of body size in Australian desert lizard communities at local scales only: no evidence for the Narcissus effect

  • Daniel L. Rabosky
  • Julian Reid
  • Mark A. Cowan
  • Jeff Foulkes
Community Ecology

DOI: 10.1007/s00442-007-0849-1

Cite this article as:
Rabosky, D.L., Reid, J., Cowan, M.A. et al. Oecologia (2007) 154: 561. doi:10.1007/s00442-007-0849-1


Both local and regional processes may contribute to community diversity and structure at local scales. Although many studies have investigated patterns of local or regional community structure, few have addressed the extent to which local community structure influences patterns within regional species pools. Here we investigate the role of body size in community assembly at local and regional scales in Ctenotus lizards from arid Australia. Ctenotus has long been noted for its exceptional species diversity in the Australian arid-zone, and previous studies have attempted to elucidate the processes underlying species coexistence within communities of these lizards. However, no consensus has emerged on the role of interspecific competition in the assembly and maintenance of Ctenotus communities. We studied Ctenotus communities at several hundred sites in the arid interior of Australia to test the hypothesis that body sizes within local and regional Ctenotus assemblages should be overdispersed relative to null models of community assembly, and we explored the relationship between body size dispersion at local and regional scales. Results indicate a striking pattern of community-wide overdispersion of body size at local scales, as measured by the variance in size ratios among co-occurring species. However, we find no evidence for body size overdispersion within regional species pools, suggesting a lack of correspondence between processes influencing the distribution of species phenotypes at local and regional scales. We suggest that size ratio constancy in Ctenotus communities may have resulted from contemporary ecological interactions among species or ecological character displacement, and we discuss alternative explanations for the observed patterns.


Character displacement Community assembly Competition Null model Regional diversity 

Supplementary material

442_2007_849_MOESM1_ESM.doc (34 kb)
ESM1 (DOC 34 kb)
442_2007_849_MOESM2_ESM.xls (19 kb)
ESM2 (XLS 19 kb)
442_2007_849_MOESM3_ESM.xls (26 kb)
ESM3 (XLS 27 kb)

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Daniel L. Rabosky
    • 1
    • 2
  • Julian Reid
    • 3
    • 4
  • Mark A. Cowan
    • 5
  • Jeff Foulkes
    • 6
  1. 1.Department of Ecology and Evolutionary BiologyCornell UniversityIthacaUSA
  2. 2.Cornell Lab of OrnithologyIthacaUSA
  3. 3.Fenner School of Environment and SocietyAustralian National UniversityCanberraAustralia
  4. 4.CSIRO Sustainable EcosystemsCanberraAustralia
  5. 5.Department of Environment and ConservationWannerooAustralia
  6. 6.Department for Environment and HeritageAdelaideAustralia

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