Mother-infant interactions and infant development in long-tailed macaques (Macaca fascicularis)

This project aims to study early face-to-face communication between mothers and infants, and their influence on infants’ development in long-tailed macaques living in Templer Park, Kuala Lumpur (Malaysia).
Work in humans has shown that the synchronized facial communication between mothers and infants, characterized by an exchange of an array of visual, auditory and tactile signals, plays a key role for infants’ socio-cognitive development, and a handful of studies on non-human primates has shown that some species exhibit similar patterns of face-to-face interactions between mothers and infant, and that this type of mother-infant communication influences infant social development. However, work examining mother-infant face-to-face signal exchanges in primates has heavily focused on few species, in particular  rhesus macaques and, to a lesser extent, gelada baboons, and chimpanzees. This project, thus, aims to extend the investigation of this type of interactions to other primate species, by addressing two main questions: (1) do early social exchanges between mother and infant in long-tailed macaques show common specific features, such as behavioral synchrony, imitation and behavioral contingencies similar to humans and rhesus macaques?, and (2) does the ability to achieve synchrony within the context of reciprocal exchange with their mothers promote the development of infant prosocial behaviors and influence their social competencies later in life?

Coupled Natural-Human Systems (CNHS)

The growing expansion of human settlements has increasingly placed humans in close proximity to other animals, including non-human primates. The overall goal of this project is to investigate human-monkey conflict dynamics as a coupled system in which humans and monkeys influence each other. This project will shed the light on what drives the conflict both in the human system (e.g. religion, age, ethnicity, etc...) and in the primate system (e.g. rank, sex, sociability) across three different field sites and three different macaque species (rhesus, long-tailed and bonnet macaques). I am currently leading the project to study rhesus macaques in the city of Shimla, the capital of the Indian State of Himachal Pradesh, in Northern India, while the other two field sites are located in Kuala Lumpur, Malaysia (long-tailed macaques) and Thenmala, Southern India (bonnet macaques).

Selected Publications:
-Kaburu et al. (in press). Interactions with humans impose time constraints on commensal rhesus macaques. Behaviour.
-Kaburu et al. (2019). Rates of human-macaque interactions affect grooming behavior among urban-dwelling rhesus macaques (Macaca mulatta). American Journal of Physical Anthropology

Development of social cognition in infant rhesus monkeys

Like in humans, mother and infant rhesus monkeys form a strong social bond and mothers engage in a variety of communicative gestures with infants, such as lipsmacking, exaggerating head movements and mutual gazing. These early interactions can have a strong impact on infant's developmental trajectory. The aim of this project is to explore the early predictors of infant social development both in nursery-reared and semi free-ranging infant macaques housed at the Laboratory of Comparative Ethology of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at Poolesville, MD (USA). This project was conducted in collaboration with Pier Francesco Ferrari from University of Parma.

Selected Publications:
-Simpson et al. (in press). Handling newborn monkeys alters later exploratory, cognitive, and social behaviors. Developmental Cognitive Neuroscience.
-Kaburu et al (2016). Neonatal imitation predicts infant rhesus macaque (Macaca mulatta) social and anxiety-related behaviours at one year. Scientific Reports, 6: 3499.
-Dettmer, Kaburu, Simpson et al.  (2016). Neonatal face-to-face interactions promote later social behavior in infant rhesus monkeys. Nature Communications, 7: 11940.

Social interactions in semi-free ranging rhesus macaques

Rhesus macaques form large multi-male multi-female social groups with an average group size between 10 and 80 individuals. While males emigrate to neighbouring communities, females remain in their natal group and form linear dominance hierarchies on the basis of their matrilineal kinship. The aim of this project is to explore social interactions, and dominance rank and their impact on individual stress levels in a semi-free ranging colony of rhesus monkeys housed at the Laboratory of Comparative Ethology at NICHD (USA)

Selected Publications:
-Wooddell et al. (2017). Rank acquisition in rhesus macaque yearlings following permanent maternal separation: the importance of the social and physical environment. Developmental Psychobiology.
-Wooddell et al. (2016) Relationships between affiliative social behavior and hair cortisol concentrations in semi-free ranging rhesus monkeys. Psychoneuroendrocrinology, 84: 109-115.
-Wooddell et al. (2016). Matrilineal behavioral and physiological changes following the death of a non-alpha matriarch in rhesus macaque. Plos One, 11: 0157108.

Grooming reciprocity in wild chimpanzees

Social grooming is the most common affiliative behaviour in non-human primates. It offers hygienic and stress-relief benefits to the recipient but it also imposes some costs to the groomer, who has to take away time from other activities, such as resting or feeding. The main aim of this project is to explore the mechanisms, strategies and social factors by which wild chimpanzees maintain reciprocal grooming interactions and whether grooming is traded for other services, such as agonistic support or meat.

Selected publications:
-Newton-Fisher & Kaburu (2017). Grooming decisions under structural despotism: the impact of social rank & bystanders among wild chimpanzees. Animal Behaviour, 128: 153-164.
-Kaburu & Newton-Fisher (2016). Bystanders, parcelling and an absence of trust in the grooming interactions of wild chimpanzees. Scientific Reports, 6: 20634.
-Kaburu & Newton-Fisher (2015). Egalitarian despots: hierarchy steepness, reciprocity and the grooming-trade model in wild chimpanzees, Pan troglodytes. Animal Behaviour, 99: 61-71.