DISSERTATION RESEARCH: Female Multiple Mating

Oregon State University, Corvallis OR

Investigators

Abstract

Females of many species receive no tangible benefits from their mates, other than inseminations. Although a single mating usually is sufficient to fertilize all of a female's eggs, some females will mate many times, even when mating may be costly (e.g., increased risk of predation). Although earlier studies failed to identify particular benefits, this earlier work did not address events that may occur during a critical period. This period occurs after insemination but before the sperm is used to fertilize eggs. The proposed study will use a combination of laboratory and field investigations to examine why female multiple mating occurs in a terrestrial amphibian (a woodland salamander, Desmognathus ocoee). In this species, the physiological mechanisms that act just prior to fertilization include sperm precedence, sperm competition, and female sperm choice. These mechanisms are likely to mediate female benefits and therefore mating propensity. Mating strategies adopted by females can have important consequences for reproductive success, and therefore for conservation efforts. Although conservation research has largely focused on aquatic-breeding amphibians (especially frogs), terrestrial amphibians also are important study systems. The proposed investigations will provide a unique opportunity to gain insight into what may be common fundamental processes affecting female multiple mating.