Baby Monkey Taken in by Another Mother in Shocking Twist todayheadline

Nestled within the thick woodlands of the Guanyinshan National Nature Reserve in Qinling, China, scientists have observed an extraordinary adoption case among golden snub-nosed monkeys (Rhinopithecus roxellana), challenging conventional theories about primate caregiving and social behavior. This unprecedented event, recorded in 2020, highlights the complexity of primate society and suggests an advanced level of social intelligence and evolutionary cognition in these strikingly colored monkeys. These monkeys have a very similar social structure to our humans (hierarchical structure consisting of different one-male and multi-female breeding groups and an all-male bachelor group within a geographic population with 200-300 individuals, like a small community in humans).

A team of scientists from the Shaanxi Key Laboratory for Animal Conservation at Northwest University, including Professor Baoguo Li, Dr. Haitao Zhao, Professor Ruliang Pan, and others, carried out the research work, which was published in the peer-reviewed journal Animals, meaning experts in the field evaluated the study before publication to ensure accuracy and credibility. The scientists documented a female monkey adopting an infant not her own, a behavior not observed and reported in Old World monkeys. “By adopting an infant with a genetic link to the dominant male of her group, the female may have increased the chances of her offspring’s survival and consolidated her relationship with the male – there is always a challenge among females in setting up the relationship the male, similar to the situation between the emperor and his concubines in ancient China,” explained Professor Pan. This novel observation adds a new dimension to understanding primate adoption and evolution, often linked to kinship or communal caregiving.

Golden snub-nosed monkeys usually organize themselves in structured social groups at multiple levels, where dominant males control the harems of females and their offspring. In this case, the high-ranking female monkeys have more chances to generate infants. However, as humans, out-group (family) mating in males and females happens occasionally. The female monkey reported in this study first had an infant sired by a dominant male in another group. Thus, her baby was facing the danger of infanticide, which has been reported frequently in this and other monkey species. The infant she adopted has no biological relationship with her – an offspring produced by her dominant male and a female in another group. Genetic analyses clarified such a biological relationship. Thus, such an adaption strategy is supposed to protect her biological offspring from potential infanticide – dominant males killing infants without their genetic linkage to bring females into reproductive readiness for him.

Professor Li’s reach team at Northwest University, Xian, China, carefully observed and documented many occasions of nursing and caregiving in this and other primate species, including, such as carrying, grooming, and protecting the adopted infant. Interestingly, the female monkey exhibited the same level of care for both her biological infant and the adopted infant, with no observable favoritism, reinforcing her role as a true adoptive mother rather than a mere temporary guardian. “Our findings challenge the traditional view that allomaternal care, a term for caregiving provided by individuals other than the biological mother, such as other females in the same group, in nonhuman primates, is limited to close relatives or females seeking reproductive experience,” noted Professor Li. This adoption pattern suggests that golden-snub-nosed monkeys may possess a level of cognitive sophistication previously thought to be unique to Hominids, including bonobos, orangutans, gorillas, chimpanzees, and humans.  

This event sheds light on social behavior and reveals the natural forces that influence how primates live and interact. The adoption likely served as a social strategy, allowing the female monkey to maintain stability within her group and reduce conflict, especially the harm to her infant. Golden snub-nosed monkeys, which evolved in the harsh climates of the Pleistocene glaciation, a period of repeated ice ages that shaped many animal species’ environment and survival strategies, including human ancestors, developed complex social structures to enhance survival. Their cognitive abilities, supported by a highly developed brain and advanced facial muscles, enable them to navigate these intricate relationships.

The research sheds new light on the intelligence and adaptability of golden snub-nosed monkeys, reinforcing their status as one of the most socially sophisticated Old World monkeys in primate evolution. By documenting this rare instance of adoption, the research work underscores the intricate social strategies these primates employ to ensure group cohesion and individual survival. As Professor Li aptly put it, “This case opens new doors for understanding how primates, including humans, navigate complex social structures for the benefit of their offspring and group stability and exploring how such phenomena have evolutionarily developed from the Old World monkeys, and greatly expressed in Hominids, especially modern humans (Homo sapiens).”

Journal Reference

Zhao, H.; Li, J.; Wang, Y.; Li, N.; Pan, R.; Li, B. “A Unique Case of Adoption in Golden Snub-Nosed Monkeys.” Animals, 2024, 14. DOI: https://doi.org/10.3390/ani14213075

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