March 26, 2011: mating systems is who mates with whom, and under what conditions. The different ways in which animal societies are structured with respect to what individuals mate and pair bond with each other. If we look at the number of individuals someone mates with: 1 = monogamy. I t was hard for people to figure out what was really going on. It is based on the observed interactions between individuals. Because of differences in parental investment: why do we have systems that are not polygynous, male genetic monogamy is a puzzle, about 3% of mammals and 90% of birds are monogamous. Social monogamny is far more common in birds. www. notesolution. com. Females have a short period receptivity, and produce eggs. And males will only fertilize one female"s eggs: sea horses : similar to pipe fish. The females give eggs to only one male, and male accepts eggs from only one female.