Causes of mate fidelity and divorce in the Seychelles warbler

Activity: Talk and presentationAcademic presentationAcademic


In socially monogamous species, individuals may occasionally divorce. This is often adaptive, although causes of mate switching can be non-adaptive as well. To date, there is a lack of studies investigating multiple adaptive and non-adaptive predictors of divorce and mate fidelity in birds. Here, we investigate the causes of divorce in a socially monogamous cooperative breeder; the Seychelles warbler (Acrocephalus sechellensis). We test several hypotheses on why some partnerships persist whereas others result in divorce using a 25 year dataset of a closed population based on the following factors: reproductive success, partnership length, age, breeding experience, partner quality, number of breeding vacancies, breeding territory quality, and food abundance. Firstly, we hypothesize that divorce may be caused by low reproductive success with the current breeding partner and breeding territory, especially directly following a failed breeding attempt. Secondly, we expect older individuals in long-lasting partnerships to divorce less due to mate familiarity and the breeding experience of their partner. Thirdly, available breeding vacancies may provide opportunities to improve in territory and partner quality, resulting in higher divorce rates. Alternatively, limitations in breeding vacancies may induce forced divorce, whereby one partner is evicted by a usurper taking over the breeding position, due to high competition for breeding positions. Finally, variable food availability may affect divorce likelihood; low food availability may disrupt the pair bond due to challenging conditions and costs in terms of reproduction and physiology. This study provides a comprehensive overview on the adaptive and non-adaptive causes of mate fidelity and divorce.
Event titleInternational Society for Behavioral Ecology Congress 2022
Event typeConference
Conference number18
LocationStockholm, SwedenShow on map
Degree of RecognitionInternational