 Dear students, in this topic we shall discuss parental care. Parental care is to fulfill or cater the needs of the newborn and young ones of a species by the parents. It is more evolved in those animals in which the newborns and young ones cannot care for themselves. This behavioral need has been an important factor in the evolution of mating systems of various species. First we shall discuss parental care in birds. Birds show maximum parental care. Because mostly the newly hatched birds cannot care for themselves and they require large and continuous food supply. Young birds have so many food requirements that it is impossible to fulfill them for a single parent. The reason is that most birds form monogamous pairs to enhance the viability of the survival. In which males stay with females and help her till the offspring are able to fulfill their own needs. In mammals, the nourishment of youngs is carried out because of production of milk by the female. She provides most of the required care. Males usually do not play any role in raising the young. However, in some species, for example, lions, males provide protection to the females and young. In such species, a single male or a group of males take care of many females at once in a harem. Here students, if parental care is not required, then polygyny prevails in such species. Males in many mammals and birds do not stay with their partners if young ones can feed and care for themselves after hatching. Males of these species actually maximize their reproductive potential and reproductive success by seeking other mates. So polygyny is more common in such species. Males' parental care is associated with another factor, that is the certainty of paternity. The mating behavior and parental care of males is often present in only those species when males are certain of their paternity of some offspring. The certainty of paternity actually is very low in species. Even monogamous relationships, maybe parents or male parent cannot believe or cannot trust about the paternity because that is why the male parental care is found in very few species in birds and mammals. In those species in which male parental care is present, males engage in behaviors that increase the certainty of paternity. Such behaviors include, first, guarding the females, number two, removing any sperms from the female reproductive tract before copulation and introducing large quantities of sperms to displace the sperms of any other males.