My current work concentrates on the evolution of female-choice preferences. There are any number of hypotheses to account for why females use certain cues and not others to select mates, and most are neither mutually exclusive nor testable. My approach has been to look at female preferences in species without female choice, to see if (when allowed to choose) females have biases in the absence of the opportunity to express them. I have concentrated on a family of live-bearing fish which includes mollies, guppies, mosquitofish, platys, and swordtails. I find that females in male-contest or male-scramble species nevertheless have strong preferences —preferences that correspond to the male dimorphisms that have evolved in more derived species in their genus. The biases appear to be associated with recognizing signs of health prior to making choices about which fish to school with. The male dimorphisms that have evolved later appear to be supernormal stimuli that exploit these biases.
More generally, I am interested in many aspects of animal communication, navigation, planning, learning, and innate recognition.