Grant: Discovery Grants Program - Individual

I study the social, hormonal and environmental factors that affect the parental care decision of birds and mammals. Parents in biparental species (both parents provide care) must balance the needs of their offspring with their own and their partners' requirements for maintaining healthy condition. I focus on one mammalian system (humans) with highly variable paternal care and two seabird species (common murres and Atlantic puffins) with obligate biparental care. We showed that there are two testosterone (T) patterns in human fathers: some fathers have lower T and consistent high quality interactions with their young children. Other fathers have higher pre-test T levels that decline if they have a high quality interaction with their child, particularly if the mother was less involved in the interaction. In this grant period I will examine how oxytocin (OT), considered to be a bonding hormone, interacts with T to affect paternal responsiveness. For example, we predict that high OT levels prior to father-infant contact will cause the greatest decline in T, particularly in the less paternal, high T men. Understanding the links between paternal interactions and hormonal responses could help shape social policy that promotes increased father involvement throughout society. I study two seabird species that differ in mate assessment strategies. The open cliff-nesting common murres trade off parental duties with their mate (one mate is always with the chick) and thus birds knows their mate's parental quality. In contrast, in the burrow-nesting puffin, both mates can forage simultaneously and the chicks' begging behavior and condition are the parent's only cues about how hard their mate is working. We will continue to study mate and parent-young behavioral interactions in years with different levels of prey (capelin) availability to determine how environmental factors impact adult physiology (stress hormone levels, lipid metabolism) and affect parental decisions to feed self or the chick. Through my continuing collaborative studies with Environment Canada, my seabird research can also contribute to conservation and wildlife management decisions that will protect the marine environment.