Polygyny in animals

Polygyny (pəˈlɪdʒɪniː; from Neo-Greek πολυγυνία, from πολύ- poly-, "many", and γυνή gyne, "woman" or "wife") is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another. Polygyny is typical of one-male, multi-female groups and can be found in many species including: elephant seal, spotted hyena, gorilla, red-winged prinia, house wren, hamadryas baboon, common pheasant, red deer, Bengal tiger, Xylocopa sonorina, Anthidium manicatum and elk. Often in polygynous systems, females will provide the majority of parental care. When two animals mate, they both share an interest in the success of the offspring, though often to different extremes. Unless the male and female are perfectly monogamous, meaning that they mate for life and take no other partners, even after the original mate's death, the amount of parental care will vary. Instead, it is much more common for polygynous mating to happen. Polygynous structures (excluding leks) are estimated to occur in up to 90% of mammals. Polygyny in birds occurs infrequently when compared to mammals, as monogamy is most commonly observed. Evolutionarily speaking, polygyny in birds might have evolved because many females do not require male support to care for their offspring. Because females do not need extra help raising their nests, males can afford to invest in multiple females. Nonetheless, male parental care is often found in many polygynous territorial bird species, leading to female competition for male assistance. Most often, males will seek a second female to impregnate, once the first female has laid her eggs.