Monogamy in primates

Primate monogamy, or the condition of having a single partner, is a multifaceted, dynamic, and complex social and reproductive strategy. Monogamy is more common among primates than it is in other mammals. Two main routes may lead to social monogamy or pair‐living: (1) when a male guards a single female instead of searching for additional fertilization opportunities; or (2) when a male is needed to protect a female's progeny against infanticide. Lifelong social monogamy seems absent in primates, and re‐pairing usually occurs after a partner died, deserted, or was forcefully replaced. Sexual monogamy is rare in socially monogamous primates, and extra‐pair copulations (EPCs) have been documented across such diverse groups as pair‐living lemurs, tarsiers, New World monkeys, and apes. EPCs only sometimes result in conception, and the majority of molecular genetic studies on pair‐living primates indicate a low rate of extra‐pair young (EPY) (≤ 10%). Notable exceptions are the high rates of EPY (≥ 20%) found in Lariang tarsiers, fork‐marked lemurs, and fat‐tailed dwarf lemurs.