Early naturalists observed conspicuous and exaggerated traits in male animals across taxa and recognized that—because these traits were unlikely to enhance survival—they required specific explanation in order to be reconciled with the theory of natural selection. Since that time, the research on sexual selection has produced a great and detailed body of knowledge about the processes of reproductive competition in males and how those processes give rise to observed patterns of diversity (from molecular to organismal) in the natural world. In recent decades, examples have accumulated of traits that appear to be secondary sexual characters in female animals across taxa (e.g. insects, crustaceans, birds, lizards, mammals). These traits tend to have salience in the context of mating or courtship but often are observed in species where females are not mate-limited; therefore, they are not explained simply by the mirror-image process of sexual selection in males. Instead, they are increasingly recognized as indications that other types of selection at work in the lives of female animals, forces fundamental to the biology of females that remain poorly understood. This symposium highlights current research focused on female ornamentation and reproductive competition in females when they are not mate-limited, showcasing a compendium of possible mechanisms.