polygynandry

Polygynandry is a mating system in which both males and females have multiple mating partners within a social group, and there are no exclusive long-term pair bonds between a single male and a single female. This pattern contrasts with polygyny (one male with several females) and polyandry (one female with several males), as well as with arrangements in which mating is largely promiscuous but bonds remain weak or absent.

In species that exhibit polygynandry, mating opportunities often arise from ecological or social conditions such as dispersed or fluctuating resources, high population density, or social tolerance that supports multiple concurrent partnerships. Paternity is frequently uncertain, which can influence parental investment and social organization. Both female choice and male competition can shape who mates with whom, as well as patterns of affiliation, aggression, and cooperation within the group.

Benefits of polygynandry may include greater genetic diversity in offspring and the potential for multiple caregivers or social bonds that support group living. Costs can include increased conflict over mating opportunities and reduced paternal certainty. The balance of advantages and drawbacks depends on ecological context and species-specific social structures.

Well-documented examples occur in certain primates, such as bonobos and chimpanzees, where females and males engage in multiple partnerships and mating is frequent within the group. The arrangement has also been observed in various other mammals, birds, and fish, though its prevalence and ecological drivers vary widely. In humans, forms of polygynandry have been discussed in anthropological contexts, reflecting cultural and historical variation in mating systems.