Summary
Prolactin is often referred to as the “parental hormone” because there is a clear and well-established role for this hormone in maintaining parental behavior in many animals. Yet, there is a seasonal prolactin peak in avian obligate brood parasites, which are birds that leave their eggs in nests of different species rather than build their own nest, incubate their own eggs and feed their own newborns. Elevated prolactin in species that provide no help to their offspring indicates that circulating prolactin levels may be insufficient or misleading in assessing how levels of this hormone motiva
