Washington, Sept 14 (ANI): Female spider monkeys without infants hug mother monkeys in exchange for permission to miss, sniff and touch their babies, primatologists have found.

Lead author Kathy Slater said the study in the journal Animal Behaviour not only showed how much primates, especially females, valued infants, but also revealed that even among apes, an embrace conveyed good intentions.

“An embrace is defined as one monkey approaching another monkey and wrapping their arms around them, in very much the same way as humans do, with one arm wrapped around the neck and the other around the waist,” said Kathy.

Slater, a researcher in the Department of Psychology at the University of Chester, said an embrace was often accompanied by a “kiss on the cheek” and a “pectoral sniff” when one monkey moved its head next to the other monkey's chest scent glands to get a whiff.

She said both males and females hugged each other when they hadn’t seen each other for a while.

Males will also sometimes hug each other in front of females “to reduce tension and prevent aggression” in a situation that can foster competition, Kathy wrote in her study.

However, observations that females without young often embrace new mothers is new, she said.

As part of her study, she and her team observed hugs received by 15 such mothers in two communities at Otoch Ma'ax Yetel Kooh reserve in the Yucatan Peninsula, Mexico.

The team found that in most instances, a recently embraced mother would grant the hugger permission to handle her infant, which the mother carries for the first year of its life.

The mother did not release the baby, but granted the hugger permission to sit in close proximity and handle the infant.

On the other hand, mothers approached by females who did not offer a hug, protectively snubbed the curious females by either turning their bodies to create a physical barrier, or by moving – baby in tow – away from the approaching individual.

Slater said embraces in spider monkeys appeared to be a method of reassuring the recipient of benign intent and reducing tension.

“Embracing is a potentially risky behaviour, as it exposes vulnerable parts of the body, such as the shoulders, face and neck, and is therefore an honest signal to the mother that the (hugger) does not intend to harm her or her baby,” Discovery News quoted Slater, as saying. (With Inputs from ANI)