Seeing a monkey drink her own milk is very rare, which is why it always attracts attention. But the strangest thing is not the act, but the why. Well, according to some observations, the monkeys did it more frequently after losing their young. Thus, scientists speculate that pain would exaggerate this action to relieve the stress of the loss or increase her immune system.
However, this can be deduced from what has been seen, and it has come to be thought that this behavior can be learned, since it was only seen in one of the two groups of monkeys observed by Dr. Bonaventura Majolo and his doctoral student. , Richard McFarlan, in the Atlas Mountains of Morocco.
Dr. Majolo points out that this is the first study to link self-sucking to calf death, and that until now scientists have only observed it in chimpanzees and feral goats. He reported that while observing monkeys nursing for other projects, they saw that when giving her calf one teat, the mother would suck on the other for a few seconds, before switching it to her. With that, Majolo thought that it was a way to stimulate the flow of milk. However, the monkeys lost their young, and self-sucking was done more frequently and longer, up to two minutes.
Details of the find were published in the American Journal of Physical Anthropology, where they point out that they can only speculate about the cause, suggesting some: being a way to recover the energy that had been invested in breeding and producing milk; help relieve congested sinuses (in my opinion this option is more reasonable), or strengthen your immune system. Or, the “most interesting” explanation, according to Malojo, to make the emotional consequences of losing a baby more bearable.
Majolo supports his preference for this explanation by referring to the role lactation plays in humans and other species, “reducing stress through the release of prolactin. Therefore, it is possible that self-suction serves to reduce the stress generated by the loss of the baby”.
We will have to wait for more data and new research.