Allomothering
Encyclopedia
Allomothering, or non-maternal infant care, can be performed by males such as a child’s father, non-reproductive males in polyandrous systems, or older siblings interested in abetting their own genetic material via their siblings (Theory of Inclusive Fitness
).
Vervets
, cebus monkeys
, squirrel monkey
s, and macaque
s are all known for allomothering performed by females not closely related to the pair. These alloparents help by carrying the infant, providing food, and guarding the infant from predators. Cebus monkey females have even been known to nurse infants not their own when looking after them (cf. wet nurse
).
Jane Lancaster noted the reproductive benefits for primates as k-strategists
in learning to be better moms. Her learning-to-mother hypothesis postulates that primate females with no children of their own participate in allomothering, and evidence from studies by Sarah Hrdy and Lynn Fairbanks shows that females without offspring "tried to allomother more frequently than what you'd expected based on their proportion of the group's population, while parous females tried it much less than expected from their population in the group."
The theory is supported by evidence of the success of allomothering as a learning technique. "Lynn Fairbanks studied vervets and found that first-time mothers with high alloparenting experience raised 100% of their first offspring to maturity, but mothers with low experience had less than a 50% survival rate of their first infant."
An infant's birthmother, in a climate of allomothering, gains time relieved from parental duties, allowing her to forage more and reproduce more quickly. It also improves the chances for her infant to be adopted should she die.
Allomothering can also be performed by non-reproductive helpers like in the callitrichids
(marmoset
s and tamarin
s).
Inclusive fitness
In evolutionary biology and evolutionary psychology, the inclusive fitness of an organism is the sum of its classical fitness and the number of equivalents of its own offspring it can add to the population by supporting others...
).
Vervets
Vervet Monkey
The vervet monkey , or simply vervet, is an Old World monkey of the family Cercopithecidae native to Africa. The term "vervet" is also used to refer to all the members of the genus Chlorocebus....
, cebus monkeys
Capuchin monkey
The capuchins are New World monkeys of the genus Cebus. The range of capuchin monkeys includes Central America and South America as far south as northern Argentina...
, squirrel monkey
Squirrel monkey
The squirrel monkeys are the New World monkeys of the genus Saimiri. They are the only genus in the subfamily Saimirinae.Squirrel monkeys live in the tropical forests of Central and South America in the canopy layer. Most species have parapatric or allopatric ranges in the Amazon, while S...
s, and macaque
Macaque
The macaques constitute a genus of Old World monkeys of the subfamily Cercopithecinae. - Description :Aside from humans , the macaques are the most widespread primate genus, ranging from Japan to Afghanistan and, in the case of the barbary macaque, to North Africa...
s are all known for allomothering performed by females not closely related to the pair. These alloparents help by carrying the infant, providing food, and guarding the infant from predators. Cebus monkey females have even been known to nurse infants not their own when looking after them (cf. wet nurse
Wet nurse
A wet nurse is a woman who is used to breast feed and care for another's child. Wet nurses are used when the mother is unable or chooses not to nurse the child herself. Wet-nursed children may be known as "milk-siblings", and in some cultures the families are linked by a special relationship of...
).
Jane Lancaster noted the reproductive benefits for primates as k-strategists
R/K selection theory
In ecology, r/K selection theory relates to the selection of combinations of traits in an organism that trade off between quantity or quality of offspring...
in learning to be better moms. Her learning-to-mother hypothesis postulates that primate females with no children of their own participate in allomothering, and evidence from studies by Sarah Hrdy and Lynn Fairbanks shows that females without offspring "tried to allomother more frequently than what you'd expected based on their proportion of the group's population, while parous females tried it much less than expected from their population in the group."
The theory is supported by evidence of the success of allomothering as a learning technique. "Lynn Fairbanks studied vervets and found that first-time mothers with high alloparenting experience raised 100% of their first offspring to maturity, but mothers with low experience had less than a 50% survival rate of their first infant."
An infant's birthmother, in a climate of allomothering, gains time relieved from parental duties, allowing her to forage more and reproduce more quickly. It also improves the chances for her infant to be adopted should she die.
Allomothering can also be performed by non-reproductive helpers like in the callitrichids
Callitrichinae
The Callitrichidae is one of five families of New World monkeys. The family includes several genera, including the marmosets, tamarins, and lion tamarins...
(marmoset
Marmoset
Marmosets are the 22 New World monkey species of the genera Callithrix, Cebuella, Callibella, and Mico. All four genera are part of the biological family Callitrichidae. The term marmoset is also used in reference to the Goeldi's Monkey, Callimico goeldii, which is closely related.Most marmosets...
s and tamarin
Tamarin
The tamarins are squirrel-sized New World monkeys from the family Callitrichidae in the genus Saguinus. They are closely related to the lion tamarins in the genus Leontopithecus.- Range :...
s).