Relationship between morphology, dispersal and habitat distribution in three species of Libellula (Odonata: Anisoptera)

Abstract

Morphology is an important determinant of flight performance and can shape species’ dispersal behaviour. This study contrasted the morphology of flight-related structures in dragonfly species with different dispersal behaviours to gain insights into the relationship between morphology and dispersal behaviour. Specifically, wing size, wing shape and thorax size were compared in three co-occurring species from different clades within the genus Libellula (Odonata: Anisoptera: Libellulidae) to assess how these morphological traits are related to differences in dispersal behaviour and to how broadly their larvae occur across a habitat gradient. Two species had broad larval habitat distributions as well as high rates and distances of dispersal. These two species had relatively larger wings and thoraces than the third species, which was found only in permanent lakes and had limited dispersal. The hind-wings of more dispersive species also had lower aspect ratios and a relatively wider basal portion of the wing than the less dispersive species. Broad hind-wings may facilitate the use of gliding flight and reduce the energetic costs of dispersal. Determining the morphological traits associated with alternative dispersal behaviours may be a useful tool to assess the differential dispersal capacities of species or populations.

Keywords:

• Odonata
• Libellula
• dispersal
• wing aspect ratio

Acknowledgements

I am grateful to E. Werner, D. Goldberg, B. Hazlett and E. Silverman, who all provided helpful advice in developing this project and insightful comments on an earlier version of this manuscript. This research was funded by NSF grants DEB-9727014 to E. Werner, D. Skelly, R. Relyea and K. Yurewicz and DEB-0089809 to E. Werner and S. Peacor and by grants from the University of Michigan including a Sokol grant to E. Werner and S. McCauley and grants from the Department of Ecology and Evolutionary Biology and the Museum of Zoology to S. McCauley. Funding from NSERC to L. Rowe and M-J. Fortin supported S. McCauley during the writing of this manuscript. I am grateful to S. Carroll, D. Dritz, P. Epanchin and S. Schneider for helpful feedback on this manuscript. S. Schneider created the image for Figure 1 and permitted its use here.