Etheostoma flabellare, breeding male. Photo: Brian O'Doherty
Background: “Sex roles” are defined as being either choosy or competitive, with females typically the choosy sex and males the competitive. Re-examination of these classic sex roles suggest that they may not be so rigid; rather, individuals may change their behavior in response to a changing environment.
Question: Is the degree to which individuals are choosy or competitive a plastic response to changes in the operational sex ratio (OSR)?
Methods: Individuals are subject to high (2:1 female:male) and low (1:1) OSR across three seasonal time points that vary naturally in adult sex ratio. Choosiness and competitive behaviors are documented to determine whether behavior varies predictably with OSR. Parentage assays determine whether relative fitness correlates with predicted behaviors.