Thesis: Evolutionary consequences of female competition for access to mates in bushcrickets endemic to Western Australia
Much is known about the many ways in which male animals compete for access to females for mating, including the elaboration of costly male traits such as weapons (e.g. deer antlers) and ornaments (e.g. peacock tails) that arise due to sexual selection. However, because of long-standing historical biases in research questions, little attention has been paid to the same phenomenon in females.
Using the bushcricket Kawanaphila nartee (Orthoptera: Tettigoniidae), I will investigate the evolutionary consequences of female competition over access to mates. In K. nartee, males provide nutritive nuptial gifts during copulation, and when environmental food becomes unavailable, females grapple and scramble for access to calling males and their food gifts, using large body size and female-specific auditory organs to outcompete rivals. Meanwhile, males become highly selective when choosing mates, resulting in 'sex role reversal' (a reversal of the typical trend among animals, where males compete for access to choosy females).
I will investigate morphological aspects of successful females in this species, and compare populations of K. nartee from different habitats around Western Australia to determine if, when, and why such sex role reversals occurs, and what the evolutionary consequences are for females.
Why my research is important
Because the evolution of male reproductive traits tends to generate more conspicuous results, the vast majority of sexual selection research has focused on males. However, there is clear scope and abundant evidence for identical processes to shape female bodies and behaviours, occasionally to the same extent as in males but more often in cryptic, subtle, or reduced ways. Thus, my research is important in helping to correct an attention bias toward male biology.
Ultimately, understanding the similarities and differences between the sexes in the animal kingdom can inform our understanding of the evolutionary causes of differences in sex roles, helping to answer questions such as, 'Why do males and females tend to differ both morphologically and behaviourally across the animal kingdom?'