Referenced Hypotheses Description References
Good genes Extra-pair partners that signal a greater genetic proposition than the social male is sought to provide indirect benefits to her offspring (Hamilton and Zuk 1982; Birkhead 1995)
Fertility insurance Extra-pair copulations are sought to protect against infertility in her own social partner, with or without phenotype cues (Wetton and Parkin 1991; Sheldon 1994; Vedder 2022)
Sociality as a mediator of variation in extra-pair behaviour The social environment provides a mechanism for extra-pair behaviour through increased mate-choice. (Maldonado-Chaparro et al. 2018)
Intersexual antagonistic pleiotropy Non adaptive female extra-pair mating derived of alleles where the cost of extra-pair behaviour to females is small relative to the benefit to males. (Halliday and Arnold 1987; Forstmeier et al. 2014; Wang et al. 2020)
Intrasexual antagonistic pleiotropy Female extra-pair behaviour is derived of alleles traits beneficial to female fecundity, for example solicitation of social partners (considered here). (Forstmeier et al. 2014; Wang et al. 2020)