 New students, in this topic, we shall discuss the mating behaviors and systems. The mating behaviors of animals enhance the reproductive success of a species. The mating behaviors of animal species evolved through sexual selection, which is a form of natural selection. That is, mating behaviors are evolutionary features which evolved through sexual selection. The mating behaviors involve mate choice. Mate choice includes seeking or attracting mates, choosing among the potential mates and pitting for mates. Now we shall discuss the mating systems. Mating systems of different species vary. Overall, there are three types of mating systems. Monogamous mating system, Polygamus mating system and Promiscous mating system. The monogamous mating system involves an exclusive relationship of one male which mates with a single female during a breeding season. The monogamous mating system involves a single male and a single female during a mating season. Mates usually live together for longer periods, otherwise they live together in a monogamous mating system. Monogamy, however, is rare in most animal groups. It is typically found in only those groups which exhibit nesting behaviors and parental care. It is most frequent in birds because about 90% of the birds are monogamous. In few bird species, we see that pears are formed for whole life, for example swans and geese. And these members of the pair remain together throughout the year. In other words, seasonal monogamy is more common. In a polygamus mating system, an individual of one sex mates with several of the other. Polygamus relationships are of two types, Polygynous system and Polyandros system. In a polygynous system, there is an exclusive relationship of one male with several females which may be two or more. Polygynous species are generally dimorphic in which the males are often showier and larger than females. In polyandros systems, one female has exclusive relationship with two or more males. Polyandros species are also dimorphic, but here the females are generally more ornamented and larger than males. In promiscuous mating system, a member of one sex within a social group mates with any member of the opposite sex. There are no strong pair bonds or lasting relationships among the members of a promiscuous mating system. In promiscuous species, males and females are often morphologically alike. They may be difficult to distinguish based on external characters.