Parental Care and Investment

Abstract

Abstract Parental care is common throughout the animal kingdom, and much variation exists among species in how, and how much, parents care for their offspring. In most species, females care more; in others, males care more and in some, caring is more or less equally shared between the sexes. Several hypotheses have been proposed to explain patterns of parental care within and among species. These hypotheses invoke factors such as the relatedness (parentage certainty) of each parent to the brood; the sex ratio at maturation; the strength of sexual selection faced by each sex and the exact nature of any trade‐offs between caring and other activities. Work is still ongoing to develop an overarching hypothesis to explain the various patterns observed. Key Concepts Among species there is much variation in how, and how much, parents care for their offspring. Differences between the sexes in parental care can evolve if one sex has more to gain and/or less to lose by providing care. Coevolution between parental care and sexually selected traits may amplify small initial sex differences in caring over time. Individual decisions on the optimal parental investment can lead to conflict between parents, as well as between parents and offspring. In some species, care of the offspring is not the exclusive responsibility of the parents but is shared among members of a group, termed cooperative breeding. In other species, adults sometimes take care of unrelated offspring, either willingly (as in adoptions) or unwillingly (as in brood parasitism). Within species, parents sometimes adjust the amount of investment in offspring based on cues from their partner or from the offspring themselves.