In a groundbreaking study published online on June 18 in iScience, researchers have found that female chimpanzees who were more socially integrated with other females before giving birth had a significantly higher chance of raising surviving offspring. This discovery sheds light on the crucial role of social connections among female chimps, particularly in the absence of close kin.

The study, led by Joseph Feldblum, assistant research professor of evolutionary anthropology at Duke University, analyzed three decades’ worth of behavioral data from 37 mothers and their 110 offspring. The researchers focused on association and grooming behavior – how often females spent time near each other or engaged in social grooming – in the year before birth.

The results showed that females who were more socially connected had a considerable better chance of raising their babies through to their first year, the period of highest infant mortality. In fact, a female with a sociality score twice the community average had a 95% chance her infant would survive the first year, while one who was halfway below average saw that chance drop to 75%. The effect persisted through age five, which is roughly the age of weaning.

Interestingly, the researchers found that having close female kin in the group – like a sister or mother – did not account for the survival benefit. Neither did having bonds with males, who could potentially offer protection. What mattered most was having social connections with other females, regardless of kinship.

“This tells us it’s not just about being born into a supportive family,” said Feldblum. “These are primarily social relationships with non-kin.”

The researchers propose several possibilities for the survival benefit, including:

* Social females receiving less harassment from other females
* More help defending food patches or protecting their young
* Offspring being less likely to be killed by another group member
* Social connections helping these females stay in better condition – maybe better fed and less stressed – through pregnancy, giving their offspring a better chance from the get-go.

Moreover, social females stayed social after their babies were born – a sign of stable relationships, not short-term alliances. “Our results don’t prove causation, but they point to the value of being surrounded by others who support you, or at least tolerate you,” said Feldblum.

This study has significant implications for understanding human evolution and cooperation. As Feldblum noted, “Human females who don’t have access to kin – for example because they moved to a new city or village – are still able to form strong bonds that can benefit them.” Studying these social dynamics in chimpanzees can help us understand how we evolved to be the social, cooperative species we are today.

The world of animal communication has long been thought to be a realm of simple signals and basic vocalizations. However, groundbreaking research from The University of Warwick is challenging this notion by revealing that wild orangutans possess a sophisticated form of communication previously believed to be uniquely human – the ability to create layered complexity through recursion.

Recursion, the repetition of language elements in an embedded way, allows for the creation of comprehensible thoughts or phrases. This complex concept has long been associated with human language, enabling us to convey intricate ideas and emotions. But research published in Annals of The New York Academy of Sciences shows that orangutans have taken this ability to a new level.

Dr. Chiara De Gregorio, Research Fellow at The University of Warwick, led the study alongside Adriano Lameira (also Warwick) and Marco Gamba (University of Torino). They analyzed the vocal data of alarm calls from female Sumatran orangutans and found that their sounds exhibit a self-embedded structure across three levels – an impressive third-order recursion. This finding challenges the long-held assumption that recursion is uniquely human.

The researchers discovered that the orangutans’ calls follow a musical-like pattern, with rhythms nested inside each other in a sophisticated multi-layered vocal structure. What’s more, they found that the orangutans adapt their vocal rhythms depending on the type of predator they encounter – faster and more urgent for real threats, slower and less regular for perceived but non-threatening stimuli.

This remarkable ability to convey meaningful information about the outside world through structured vocal recursion is a testament to the complexity and intelligence of wild orangutans. As Dr. De Gregorio notes, “This discovery shows that the roots of one of the most distinctive features of human language – recursion – was already present in our evolutionary past.”

Orangutans are helping us understand how the seeds of language structure might have started growing millions of years ago. This research presents the first empirical support for the idea that these powerful recursive capacities could have been selected for and evolved incrementally in a much earlier ancestor.

In conclusion, the hidden complexity of wild orangutans’ communication has shed new light on our understanding of animal intelligence and the evolution of language. As we continue to explore and study these remarkable creatures, we are reminded of the awe-inspiring capabilities that exist within the natural world.

A groundbreaking study by researchers at the Max Planck Institute of Animal Behavior (MPI-AB) has uncovered that wild Sumatran orangutan mothers exhibit unique parenting styles, even after accounting for biological, social, and environmental factors. The research team analyzed data on six maternal behaviors collected over 15 years, revealing consistent differences among mothers in their care-giving approaches.

Revathe Thillaikumar, a postdoctoral researcher at MPI-AB, stated that “our study shows that Sumatran orangutan mothers are not all the same when it comes to parenting behaviors.” For example, some mothers consistently carried their infants on their backs more frequently than others, while some terminated body contact more often. These differences remained consistent across each mother’s different offspring, even after controlling for known factors affecting maternal behavior.

The study also explored how maternal behavior changes as infants develop, given that Sumatran orangutans have the longest recorded infant dependency of any nonhuman animal. The researchers found that mothers made flexible adjustments to their parenting behaviors and consistently differed from one another in these adaptations. For instance, while all mothers tended to decrease spatial proximity more frequently as their infants grew older, some mothers did so more than others across all their offspring.

The study examined six essential maternal behaviors towards the infants: body contact, staying close, carrying, feeding nearby, and teaching skills directly. These behaviors significantly impact how infants learn and navigate dense canopies in a tropical rainforest. Data were collected at the Suaq Balimbing research site in Indonesia from 22 mother-infant pairs over more than 6000 observational hours.

Caroline Schuppli, a group leader at MPI-AB, concluded that “the consistent differences among mothers – both in the extent of their behaviors and in how these behaviors changed over the course of infant development – suggest that orangutans may possess individual maternal personalities.” The researchers noted that they do not yet understand whether these differences bring about variations in aspects of infant development. They plan to accumulate more data over a decade to investigate the effect of these differences on infant development, shedding further light on the complexities of orangutan parenting styles.