Meeting Abstract
Parental care, defined as any behavior that increases an offspring’s fitness, is a widespread phenomenon observed in many diverse taxa which has evolved independently numerous times resulting in species-specific parental behavior. While it is clear that species have converged on parental care in order to increase fitness, it is less clear whether the diversity in parental care behavior has resulted from species-specific mechanisms or whether species have co-opted similar mechanisms to promote parental behavior. The hormone prolactin (PRL) is a promising candidate mechanism of parental care that may have conserved roles in parental care across taxa. PRL has a well-established role in maternal care in mammals and ringdoves and has been suggested to be involved in parental care in other birds, including songbirds. Currently, there are no published studies looking at PRL’s involvement in the expression of songbird parental behavior. The zebra finch, a socially monogamous, biparental songbird, is an exceptionally useful animal model to study parental care and other close social relationships. Both sexes share parental care equally and show a marked improvement in breeding success with experience. We have found that plasma PRL significantly elevates from non-breeding baseline concentrations during late incubation and early post-hatch care and that this elevation is greater in reproductively experienced birds, compared to inexperienced birds. Plasma samples were assayed using an ELISA that we validated in zebra finches. In addition, plasma PRL concentrations are highly correlated with the amount of parental care behavior displayed during days 2 and 3 post-hatch, the number of chicks that successfully hatched, as well as chick survival to fledging. Findings from these studies will be used to inform hypotheses and predictions for future work involving experimental manipulations of PRL during parental care.
