Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Mating SystemsLaksmis Cornejo, Sara Nishikawa, Shannon Oki

Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Hypotheses

Certain ecological factors determine the degree to which mates can be defended or monopolized

Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Polygamy

Prerequisite: economic monopoly of several mates

OSR: the average ratio of fertilizable females to sexually active males at any given time

an imbalance in the OSR skewed toward males then there is a greater chance of polygamy

Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Monogamy

Neither sex has the opportunity of monopolizing additional members of the opposite sex

Considerable parental care by both parents is required for successful rearing of the young

Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Polygyny

Individual males frequently control or gain access to multiple females

Resource defense polygyny occurs when males defend resources essential to females such that they can monopolize the resources and therefore the females.

Female defense polygyny usually occurs with resource defense polygyny where the females are forcibly herded by a male such that other males are excluded from the group.

Male dominance polygyny occurs when the environment does not allow for monopoly of resources or females therefore the males establish dominance amongst themselves.

Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Male Incubation/ Female Emancipation

Female viewpoint: lessensher metabolic burden and allows her to devote more time and energy to replenish nutrient and

mineral reservesMale viewpoint: insurance strategy- cost of his

incubation is beneficial in that she is able to prepare to have more kids

Rapid multiple clutch polygamy

Emlen, S.T., Oring, L.W. (1977). Ecology, Sexual Selection, and the Evolution of Mating Systems. Science, 197, 215-223

Polyandry

Individual females frequently control or gain access to multiple mates

Resource Defense Polyandry: females compete and defend resources essential to males

Male defense polyandry: females control access to males directly

Female access polyandry: Through interactions among themselves, females may limit access to males