Maternal Behavior in Otariids and the Walrus

The most energetically costly phases of female reproduction in placental mammals are gestation and lactation. For the young, the success of this relationship is based on obtaining as much maternal care as they can take in, even if this may result in a cost to future reproductive success of the mother. On the other hand, the mother should retain sufficient resources to be able to invest in future offspring, thus ensuring her own future reproductive success. These competing demands lead to a conflict between mothers and their young that eventually results in the weaning of the young, often initiated by the mother. In this review, we describe the main strategies of lactation and maternal care in fur seals, sea lions and walrus. The maternal care strategy in income-breeding pinnipeds with prolonged lactation periods, such as otariids and walrus, is influenced by group-living, and these two factors have been subject to strong selection. Maternal care in pinnipeds is influenced by both social and environmental constraints. This information plays a major role in our understanding of the social and exploratory behavior of the young, as well as into the interaction between maternal care and the development of offspring.