UC Riverside

Being a mother is energetically costly and can entail trade-offs between reproduction and self-maintenance. In biparental species, fathers, as well as mothers, care for offspring and improve offspring survival. It is unknown if fathers in these species, like mothers, experience costs of parenting. It is also not clear whether the beneficial consequences of paternal care for offspring are mediated exclusively through direct effects on offspring or whether they can be mediated indirectly through beneficial effects on mothers. This dissertation investigates energetic costs as well as behavioral and affective changes associated with fatherhood, and morphological, physiological and affective conditions in single mothers rearing offspring without assistance from their mates in the monogamous, biparental California mouse (Peromyscus californicus). Results demonstrate that cohabitation with a female and/or fatherhood decreases blood glucose levels, alters lipid profiles, as well as protects body mass and fat mass from being affected by energetic challenge. Fathers also buffer their mates from potentially adverse consequences of motherhood. Mothers rearing pups without assistance from a mate can maintain pup survival and development as normal, but experience morphological and endocrine changes that might be harmful in the long term. These experiments provide important implications for the understanding of trade-offs between reproduction and self-maintenance in a biparental breeding system.