the mother by carrying or guarding infants from predators, and in some New World monkeys such as tamarins and marmosets, helping to provision them.

Allomaternal care varies greatly across and within different species, families, subfamilies, and groups of primates. Mothers within the same group often vary significantly in the amount of access they allow allomothers. Differing levels of allomaternal care are present in almost 75% of primate species for which there is data and among 100% of callitrichids.