(1) In animals, a relationship between the sexes whereby one male mates with several females (polygyny) or one female mates with several males (polyandry). Polygyny is characteristic of many mammals. In eared seals (fur seals, sea lions), the dominant male herds a harem of 15 to 80 females, to which several younger males attach themselves. Ungulates (goats, rams, horses, deer) also form herds consisting of a dominant male and several females and other males. Polygyny is characteristic in less marked form of some rodents and insectivores that do not form harems and herds, several birds (many Galliformes, Trochili, Limicolae), and some invertebrates (many insects). Polyandry in animals occurs less frequently; it is observed in some birds, including phalaropus, Turnix, Crypturiformes).
(2) In plants, the simultaneous appearance in the same species of plants of bisexual and unisexual flowers. Both types of flowers may be found on the same or on different specimens (in various combinations). Such plants, which include ash, maple, buckwheat, and snakeweed (Polygonum bistorta), are said to be polygamous.