Preprint version. Freshwater Biology, Volume 53, February 1, 2008, pages 253-263. This is the pre-peer reviewed version of the following article:Slow, Fast and In Between: Habitat Distribution and Behaviour of Larvae in Nine Species of Libellulid Dragonfly, Shannon J. McCauley, Freshwater Biology, 53:2, Copyright © 2008 Wiley-Blackwell., which has been published in final form at http://dx.doi.org/10.1111/j.1365-2427.2007.01889.x.
NOTE: At the time of publication, the author Shannon J. McCauley was not yet affiliated with Cal Poly.
1. Activity and microhabitat use are important factors determining species performance in habitats that differ in permanence and species composition of top predators. This study examined the relationship between the distribution across a gradient of habitat permanence and an associated transition in the composition of top predators and the behaviour of species of larval dragonflies. It also assessed the relationship between larval behaviour, body size and the duration of the larval stage. In laboratory mesocosms the mobility of the different species was measured, as was the extent to which they associated with artificial vegetation.
2. Species mobility was positively related to their natural occurrence in habitats in which invertebrates or small-bodied fish were the top predators, and negatively related with the frequency with which species co-existed with large-bodied fish, the permanence of the habitat and the length of the larval stage.
3. Rather than falling into strict low and high mobility categories, habitat generalists that occurred across the habitat gradient, co-existing with different top predators, had variable mobility levels. In these generalists, mobility was positively related to how frequently they were found in natural habitats in which invertebrates were the top predators.
4. The extent to which species utilized the artificial vegetation in mesocosms was associated with the length of the larval period but was not associated with mobility or species habitat distribution in the field.