Founded in 1971, the Amboseli Baboon Project is one of the longest-running studies of wild primates in the world. The project centres on the savannah baboon, Papio cynocephalus that lives in the Amboseli basin of southern Kenya and tracks hundreds of known individuals in several social groups over the course of their entire lives.

With over 40 years of data, the project can answer questions about the relationships between social behaviour, relatedness, and population genetic structure in wild populations that would not be possible with only a few years of research. The project also addresses other aspects of baboon biology, such as genetics, hormones, nutrition, hybridization, parasitology, and relations with other species.

Susan Alberts from Duke University co-directs the Amboseli Baboon Research Project with Jeanne Altmann at Princeton University, out now in the current issue of the journal is a new Synthesis paper by Susan on Social influences on survival and reproduction: Insights from a long‐term study of wild baboons.

To complement the publication of this Synthesis paper, Susan shares some of the best photos from her fieldwork in Amboseli and reveals more about the lives of the baboons.

Figure 1. The Amboseli Baboon Research Project represents one of the best-studied wild mammal populations in the world. Conducted in the Amboseli basin of southern Kenya, the research includes full life course data, collected continuously since 1971, on more than six generations of known individuals. Photo credit: Elizabeth A. Archie.

Figure 2. The study subjects are habituated to the presence of human observers and go about their daily lives un-interuputed while they are being observed. Left: Senior Observer J. Kinyua Warutere, who has been with the project since 1995, collecting daily monitoring data. Right: Amboseli often provides excellent observation conditions. Here, the author observes baboons on a short-grass plain. Photo credits: Jeanne Altmann (left), Robert Zimmerman (right).

Figure 3. Baboons are intensely social animals, and social interactions and relationships – both affiliative and antagonistic – are a highly salient component of their environment. On the right, a young infant climbs and plays on an adult male. At least, an adult female sits near here infant. They are surrounded by other members of their social group. Photo credit: Jeanne Altmann, taken Oct 1990, in the project’s 19th year.

Figure 4. Social relationships affect an individual’s access to food and other resources, its access to information, and its vulnerability to predation. Social relationships can also represent protection against other baboons who are threatening or competitive. Probably for these reasons, individuals form social bonds early in life, and these bonds may persist for years. This is especially true for females, who remain throughout life in the social group into which they were born; males tend to move between social groups periodically. Photo credit: Chelsea Weibel.

Figure 5. Left: One adult female grooms another, while the groomer’s yearling infant nurses. Right: An adult female grooms her 16-month old daughter (foreground) while two adolescent females groom just behind them. Social grooming – picking through the fur of a partner to remove dirt, debris, and ectoparasites – is a frequent affiliative behavior in baboon social groups. Photo credits: Elizabeth A. Archie (left), Susan C. Alberts (right).

Figure 6. The number and strength of a female’s social bonds – measured via grooming relationships and other social interactions – have been linked to offspring survival, adult survival, or both, in three different wild baboon populations, including Amboseli. Photo credits: Susan C. Alberts

Figure 7. This female was badly wounded on her flanks, tail, head, and face during a series of intense aggressive conflicts among adult females that preceded a permanent social group fission. While some permanent fissions are peaceful and gradual, the one involving this female occurred over the course of only two weeks, and at least 3 infants are suspected to have died as a result of the aggression, with numerous females wounded. Conspecifics represent not only social resources, but serious social competitors: animals living in social groups must constantly balance the benefits of group living against the costs. Photo credit: A. Catherine Markham.

Figure 8. This infant’s life will be strongly affected by its early experiences: females that experience more adversity early in life have much shorter lifespans. Among females that survive to adulthood, those who experience three or more sources of early adversity die a median of 10 years earlier than ‘silver spoon’ females who experience little or no adversity. The sources of adversity that were studied include losing one’s mother in the first four years of life, having a close-in-age younger sibling, being born in a drought, born to a low-ranking mother, and born to a socially isolated mother. Note: the adult male in the foreground is wearing a radio collar, which the research team uses to help locate study groups and follow males when they move between social groups. Photo credit: Elizabeth A. Archie.

Figure 9. This infant is nursing while being groomed by his mother. Infant baboons are completely dependent upon their mother for the first year of life. Over the 47 years of the Amboseli baboon study, only a handful of infants whose mothers died in their first year of life have survived to adulthood. Even after weaning (at approximately 16 months of age) the loss of the mother has a negative effect on juvenile survival. Photo credit: Chelsea Weibel.

Figure 10. Infant baboons are born able to cling to their mother, and they ride ventrally for the first several months of life as shown by the female infant on the left. During this stage they have a black coat, in contrast to the golden-brown coats of older animals. At 2-3 months of age they learn to ride on the mother’s back as shown on the right. By this age the black natal coat has begun to turn golden-brown, resulting in the patchwork appearance seen in this 4-month old male infant. Photo credits: Susan C. Alberts (left panel), Chelsea Weibel (right panel) .

Figure 11. Muzzle-sniffing, seen here, appears to be an important source of information for infants about what is safe to eat and how various foods are processed; many baboon foods (e.g., grass corms, tree gum, tubers) require digging, opening, extracting, or separating from a substrate, and infants may require considerable time to gain the strength and knowledge to acquire these foods. Photo credit: A. Catherine Markham.

Figure 12. This 3-month old infant will not be harassed or threatened by other baboons when he is in the vicinity of this large, high-ranking male, who is highly tolerant and protective of him. Baboon males differentiate their own offspring from the offspring of other males and provide care to them; paternity analyses are pending for this infant. At the same time, this same male is suspected of killing two other infants in the six weeks prior to this photo being taken; most likely, those infants were not his biological offspring (paternity analyses are pending). Photo credit: Susan C. Alberts.

Figure 13. Adult males can be benevolent figures in an infant baboon’s life, as shown here. The adult male on the left is holding an infant who may or may not be his biological offspring; males can be benevolent or violent towards non-offspring and infants must correctly navigate their complicated social landscape in order to survive. Note the considerable difference in coat color between the male on the left and the female on the right: the Amboseli baboon population is composed mostly of yellow baboons (Papio cynocephalus) but some natural hybridization occurs with nearby populations of olive baboons (P. anubis), which are darker, producing great variation in coat colors in Amboseli. Photo credit: Elizabeth A. Archie.

Figure 14. Left: an adult male protecting a young juvenile (screaming, between his legs) against an older one (crouching in front of the male). Right: an adult male during the act of infanticide. Instead of killing the infant quickly with his teeth, as is often observed, this male ‘kidnapped’ the infant and kept it from its mother until it died of dehydration. Note again the difference in coat color between these two males; the male on the left shows clear evidence of being a hybrid yellow-olive baboon, while the male on the right shows the typical yellow baboon coat color. Photo credits: A. Catherine Markham (left) and Raphael S. Mututua (right).

Figure 15. The permanent field team of the Amboseli Baboon Research Project, responsible for the large majority of the regular monitoring and data collection. Raphael Mututua (center, back row) is the Project Manager and has been working with the Amboseli Baboon Research Project since 1981. Back row from left: Moonyoi ole Parsetau (camp staff), Lenkai ‘Nkii’ ole Rikoyan (camp cook), Jackson Kinyua Warutere (Senior Observer), Raphael Supeet Mututua (Project Manager and Senior Observer), Isaiah Longida ole Siodi (Observer), Serah Sayialel (Senior Observer), Benard Ochieng’ Oyath (Junior Observer). Front row from left: Gideon Marinka (Junior Observer), Lenkai ’Alex’ ole Meloimet (camp staff). Photo credit: Kerri Smith.

Figure 16. The leaders of the Amboseli Baboon Research Project. Far left: Susan Alberts (Duke University) on the left and Jeanne Altmann (Princeton University) on the right observing baboons. Top right: Elizabeth Archie collecting data (University of Notre Dame). Bottom right: Jenny Tung in the project’s ‘lab tent’ processing biological samples (Duke University). Photo credits: Courtney L. Fitzpatrick, Susan C. Alberts.

Figure 17. The author has not only watched many young baboons grow up, she has also watched her own daughters Michele (left) and Teresa (right) grow up during their visits to Amboseli, which were frequent when they were young. Photo credits: Robert Zimmerman.