Parental care in birds.

Parental care, a usefully imprecise catch-all term for behaviors performed by breeding adults that benefit their offspring, is a popular research area among behavioral ecologists. Across Class Aves, it takes many forms, ranging from warming the eggs during incubation - such that the embryo develops within and eventually escapes from its protective shell - to extensive post-hatching assistance, especially by providing food but also by protecting young from weather and predators (Figure 1). In this primer, I will address the evolutionary forces likely to have shaped the peculiar avian habit of involving both parents in substantial post-fertilization investments, rather than just one. For this, I will focus on the costs, benefits, and complex social dynamics associated with elaborate parental care to show that what we may regard as the simple nuclear family (mom, dad, and a few kids) is anything but simple.