Classical polyandry: the most puzzling of avian mating systems

Abstract

Abstract The term polyandry refers to a mating bond between a female and two or more males. Classical polyandry (Oring 1986) is the term used for social-mating systems where (1) a single female mates either sequentially or simultaneously with two or more males during a single breeding season, and (2) males typically form bonds with no more than one female per breeding cycle or per season. A key characteristic of classical polyandry is that each male has its own nest, where it incubates the eggs and later provides care for its (usually) precocial young, most typically with little or no help from the female. In classical polyandry, males not only provide virtually all parental care, females also compete aggressively for mating opportunities. Female-female competition is probably causally related to the reversed sexual dimorphism in body size and often colour seen in such species (e.g. Jehl and Murray 1986).