摘要: Caring for one’s offspring is so widespread among birds and mammals that it the exceptions attract our attention. Among birds, megapodes are a special curiosity precisely because their precocial young unattended by elders, even though latter may have labored long maintaining an optimal temperature in solar-heated nests (Frith, 1962). Mammals, virtue of nursing relationship between mothers young, never quite distant from offspring, but some species contact generations ends abruptly with weaning while others persists after. Why parental care not universal uniform?