Dissertation Research: Examining the Effects of Large Scale Migration on Local Population and Community Dynamics in Larval Odonates

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

Large scale movement patterns can influence the spatio-temporal occurrence of size-structure within and between populations but few studies explicitly address how these patterns affect interactions such as cannibalism and intraguild predation (IGP). The dragonfly Anax junius is a species that migrates and often assumes the role of top- predator in fishless ponds. These attributes make A. junius an ideal species for addressing the influence of migration on population size structure and local population/community dynamics. We outline experiments with A. junius and other co- occurring odonate larvae evaluating these effects. Section I tests: a) the effects of size variation on cannibalism in paired A. junius larvae and the likelihood of cannibalism within and between cohorts of A. junius; and b) the effects of size-structure and temperature, two seasonally variable factors, on cannibalism in populations of A. junius larvae. Section II tests the effects of population size-structure in a top predator (A. junius) on: a) the survival of intermediate predators and shared prey in a three species IGP system; and b) the relative contributions of density mediated interactions and trait mediated interactions on risk reduction in a three species IGP system.