Overview and History
The Primatology Research Group (PRG) is mostly interested in questions of eco-ethology and socio-ecology of primates in natural environments. Initially principally focused on mechanisms of habitat use (feeding ecology, bird nest predation, seed dispersal and evolution of home ranges), the researches of the PRG are now dedicating a growing importance to the study of primate populations’ behaviour in disturbed habitats, even human-dominated environments.
Habitat modifications, often more or less directly related to anthropic pressures, are most often threatening the survival of animal and vegetal species, and notably non-human primates. If some species demonstrate certain flexibility, others are less adaptable and therefore more fragile. The systematic evaluation of species adaptability and/or fragility when confronted to modifications of their environment is crucial for designing efficient and suitable measures of protection and conservation.
Through the study of primate behavioural ecology, the PRG is therefore increasingly interested in their conservation and in particular to the arguments underlining their importance: for instance, the seed dispersal role of non-human primates in maintenance and regeneration of forest habitats. A second theme of importance focuses on the ecological and behavioural dynamics characterizing non-human primate populations living in anthropogenic habitats, especially in Asia. In this framework, we are also developing applied research projects to help managing populations experiencing growing conflict with humans, and we are monitoring the effectiveness and potential impacts of the implemented management strategies.
The PRG researches concentrated until now on numerous species, from « great apes » (apes et « lesser-apes »): gorillas, chimpanzees, bonobos, gibbons, to « monkeys »: baboons, macaques, colobus, mangabeys, howlers, capuchins, tamarins….). The interest for species in natural environments can also imply moments of research in captivity, which we are carrying on in collaboration with partner zoos (notably Köln, Mulhouse, Strasbourg…).
The PRG gathers, in a permanent or temporary manner, the members of the primate team of the ULiege, working within the Behavioral Biology Unit, as well as external collaborators, members of the ULiege (e.g. Faculty of Veterinary Medicine) or coming from other Belgian institutions (IRScNB, ULB, UCL, UAntwerp…). We are conducting our projects thanks to long-term established collaborations with international institutions such as in Thailand, Indonesia and Brazil. The projects are using methods specific to the various problems under study and we are also turning when necessary to other discipline methodologies, in complement to the strictly ethological methods (for instance in botany, veterinarian sciences, bacteriology, parasitology, genetics,…).
Current Research Projects
1. Northern Pig-tailed Macaque Project
Eva Gazagne, PhD student
PhD research project description: Deforestation and fragmentation are among the most important threats to biodiversity: they limit animal and plant dispersal, which results in an alteration of the overall ecosystem functions such as seed dispersal and prey-predator interactions. The omnivorous and generalist northern pigtailed macaque (Macaca leonina) is known as an effective large seed disperser, contributing to the tropical rainforest succession, but also as a bird nest predator. By studying this adaptive species in the degraded forest fragment, the Sakaerat Environmental Research Station in Northeastern Thailand, this thesis aims to assess the fragmentation and degradation effect on its feeding behavior, ranging pattern, seed dispersal effectiveness and on the extent of its predator activity. In addition to present in an original way the synoptic vision of the costs (nest predation) and the benefits (seed dispersal) of this generalist primate in a degraded fragment, this research collects for the first time eco-ethological informations on this vulnerable species in a degraded environment in Thailand.
Keywords : Macaca leonina – fragmentation – ranging pattern – feeding behavior – seed dispersal – nest predation
Olivier Kaisin (master thesis BOE, 2017)
In the framework of my master’s thesis, I spent five months studying bird nest predation by northern pigtailed macaques (Macaca leonina) at the Sakaerat Biosphere Reserve in Thailand, a study part of the PhD thesis of Eva Gazagne. Using artificial nests monitored by camera traps, we showed that macaques actively searched for nests in different microhabitats, suggesting that nest predation by this primate might be considered a selective feeding behavior in this degraded habitat. Consequently, nest predation by this primate might have important conservation implications on the population dynamics of forest-dwelling bird species.
2. Balinese Macaque Project
We live an epoch of a major human-induced environmental change associated with a multiplication of contact zones between humans and wildlife. The way primates behave when facing evolutionarily novel situations is a key issue which remains poorly understood. Using an interpopulational comparative approach, we systematically investigate the anthropogenic influences on the demographic, ecological and behavioral variations in Balinese long-tailed macaques, by questioning the biological significance of the responses in terms of costs and benefits.
This research takes place in Bali (Indonesia), more specifically at the Ubud Monkey Forest, an urban forest fragment where long-tailed macaques (Macaca fascicularis) thrive in overcrowded conditions, correlated with intense social tensions amongst the macaques, and growing conflicts with humans. To control overcrowding and alleviate tension, a female sterilization program has been initiated by local stakeholders in collaboration with our PRG team of Uliege (Faculty of Sciences and Faculty of Veterinary Medicine) and the Primate Research Center of Udayana University (Faculty of Veterinary Medicine). We develop here a multidisciplinary and long-term project whose objectives are threefold: 1) Assessing the efficiency of the birth control program via demographic monitoring and trends modelling; 2) Monitoring the potential changes in behaviour and social dynamics of macaques (e.g. reduction of social tension) through an extensive ethological follow-up; and 3) Assessing the efficiency of the programme in terms of human-macaque conflict mitigation. The goal of this interdisciplinary project is to build a holistic approach taken into account needs and limits of the different actors of this interface, humans and macaques.
Gwennan Giraud, PhD student
PhD research project description: Across Asia, sterilizations of wild primate populations are increasingly used as a management strategy to control high-density populations, mitigate the conflict with humans and promote coexistence between humans and primate populations. My PhD project investigates the social dynamics (social networks, intrasexual competition, sexual motivation, alloparental care) of a population of long-tailed macaques (Macaca fascicularis) in Bali (Indonesia) following sterilization campaigns of reproductive females. Using social network analysis tools, I aim to highlight changes that could occur within the social organization of these primates following sterilizations. This study will allow us to better understand mechanisms which underpin their social dynamics and how these macaques cope with changes of reproductive status and in their social environment, particularly with regard to sterilized individuals. The applied objective is to monitor the effectiveness and potential impacts of these management strategies and to contribute in a sustainable way to the local conservation efforts of these commensal populations through mitigation of conflicts with humans.
Keywords: Sterilization – macaques – Social Network Analysis (SNA) – social dynamics – (allo)parental behaviour – sexual motivation – Bali
3. Black Lion Tamarin Project – Brazil
Olivier Kaisin, PhD student (Aspirant FNRS)
PhD research project description: I study the physiological and behavioural responses to habitat fragmentation by black lion tamarins in the Brazilian Atlantic Forest. Habitat fragmentation is one of the major threats hanging over primate populations in South America. Before affecting primates at a population level, environmental perturbations affect the physiology of the individuals. Glucocorticoids (GCs), often referred to as stress hormones, are metabolic hormones which mediate the energetic demands needed to overcome predictable and unpredictable environmental and social challenges. These physiological biomarkers play a key role in enabling individuals to respond to stressors and restore physiological homeostasis. How primates adapt to habitat fragmentation pressures remains poorly understood. The aim of this research is to investigate the physiological and behavioural responses of the endangered black lion tamarins (Leontopithecus chrysopygus) living in the Brazilian Atlantic Forest, a habitat particularly affected by fragmentation. The three specific objectives of this research are: (1) reviewing the effect of anthropogenic habitat disturbance on the well-being of primates, (2) analysing variation in chronic stress of tamarins in different forest fragment quality, and (3) relating transient stress levels to behavioural patterns. This project is conducted as a joint-PhD between ULiège and the Sao Paulo State University in Brazil (Dr. Laurence Culot). Evaluating stress levels in primate populations living in fragmented landscapes can shed light on how primates respond to such habitat perturbations and how significant it is for their survival.
Team leader: Alain Hambuckers