Research
Sex-structured population dynamics
Mating pair of C. maculatus (credit: Fleur de Crespigny)
Most theory for population dynamics considers only a single sex (typically female). One-sex approaches are often appropriate for hermaphroditic organisms, including most plants. They may also be appropriate for dioecious organisms, including most animals, if the sex ratio of individuals available for mating (operational sex ratio) is constant, in which case no information is gained by explicitly accounting for both sexes. However, in nature operational sex ratios can be highly variable. I am examining the consequences of sex ratio variation in a number of ecological contexts, including biological invasions (where females and males
Female (left) and male (right) inflorescences of Poa arachnifera, a dioecious grass. (credit: Bob Harms)
may differ in their dispersal ability), host-symbiont interactions (where symbionts can skew primary sex ratios), and populations subject to human harvesting (which is often non-random with respect to sex). This work involves a combination of mathematical models and laboratory experiments with bean beetles. We are also developing work with dioecious plants to study two-sex population dynamics in nature. (Related papers: Miller et al. 2011 Am Nat, Miller and Inouye (in press)
Ecology)
