Johann Delcourt Assistant – Postdoctoral Researcher PDR (ULiège – FRS-FNRS)

Behavioural Biology Unit, Laboratory of Fish and Amphibian Ethology,
Université de Liège, Institut de Zoologie, 22, Quai Van Beneden, 4020 Liège – Belgique

Tél : (+32) (0)4 366 50 79 – Fax : (+32) (0)4 366 51 13

Email: eb.eg1596912087eilu@1596912087truoc1596912087leD.n1596912087nahoJ1596912087

Research description

Current project (PDR): Collective intelligence as a cooperative process in fish schools

During the establishment of a consensus within an animal group, the individuals have to consider and weigh their personal information (based on their own past experiences) with the public information, based on the behaviour and the performances of the other individuals in the group. From an adaptive point of view, these collective consensuses are expected to be advantageous on average for every individual. Furthermore, reaching a consensual choice is often crucial in maintaining the cohesion of a group; the individuals who make a different choice may find themselves isolated, losing any advantage of life in a group, in particular increasing their predation risk.

In spite of undeniable advances, the question of collective intelligence (also called swarm intelligence) in social animals remains quite opened. We speak about collective intelligence sensu stricto when: 1) the individuals independently acquire information; 2) this information is combined and treated by social interactions; and 3) a cognitive problem is then solved more efficiently collectively than if the individuals tried to solve it alone. A group simply adopting a consensus in a social context is not a sufficient condition to demonstrate that a process of collective intelligence is applied. In a system based strictly on collective intelligence, there are no individuals who impose their choice, nor a centralized structure of control. No single individual possesses all the information necessary to carry out the task; rather, it is distributed among the individuals of the group. This decentralization makes it less costly (in terms of memory and energy) per individual to retain information, as well as allowing a division of labour in executing a task. It also provides greater security of information than a centralised system, where the loss of the individual holding all the information entails the loss of it completely for the group.

The main objective of the project is to explore the question of collective intelligence, from the angle of cooperation between individuals, rather than conflicts of either motivation or information. For this purpose, we use zebrafish (Danio rerio), a well-known social species which adopts schooling behaviours, as animal model of laboratory for our researches.

The laboratory approach of this project is carried out within the Behavioural Biology Unity (University of Liège), with the theoretical support of the Unity of Social Ecology (ULB).





Collective behaviours, zebrafish, Cichlids, videotracking, multitracking, fish tracking, shoaling behaviours, schooling behaviours, self-organization, emergent properties, collective decision-making, social learning, collective vortices, vortex


2015-2018 Assistant- Researcher PDR (ULiège – National Fund of Scientific Research)
Since 2015 Master of conferences (ULiège)
2014-2015 Assistant lecturer in the Departement of Biology of the Evolution and Ecology (BEE)(ULiège), attached to the Unity of Biology of Evolution and Conservation
2009-2014 Postdoctoral Researcher FRS-FNRS (National Fund of Scientific Research) (University of Liège)
2008 – 2009 Scientific Collaborator of Université de Liège
2008 PhD in Sciences (University of Liège)
2008- 2007 Grant Researcher of University of Liège (Réseau ULg) (PhD student)
2006 Master of Experiments (FELASA category C)
2003-2007 PhD student Funds for Research in Industry and Agriculture (University of Liège)
2002-2003 “D.E.A in Sciences” (M. Sc. 2) University of Liège, Belgium
2001-2002 “Licence” in Biological Sciences, animal biology (M.Sc.) Université de Liège, Belgique


BIOL2033-1: Monitoring of biodiversity & population dynamics – Co-titular (partim: population viability analysis)

Lectures in  FELASA Formation (category A, B et C) (Invited by the Faculty of Vetenary Health of University of Liège) (Legal Studies in Laboratory Animal Science accreditated by “le Service Public Fédéral Santé Publique” de Belgique):

– “Fish in laboratory and welfare” (Felasa category A, B et C)

– “Zebrafish in laboratory” (Felasa category C)


Main Collaborations

Unité d’Ecologie Sociale (USE) et CENOLI (Centre Interdisciplinaire des Phénomènes Non-Linéaires et des systèmes Complexes, Université Libre de Bruxelles, Belgium) (C.Q. FRS-FNRS Jean-Louis Deneubourg)

New Jersey Institute of Technology (USA) et le « SwarmLab » Rutgers University (USA) (Asst Pr Simon Garnier)

Department of Psychology, Wilfrid Laurier University (Asst Pr Noam Miller) (Ontario, Canada)

Department of Mathematical Sciences de l’Université d’Essex et Faculty of Engineering de l’Université de Bristol (Dr Nikolaï W. Bode) (GB)

CouzinLab of Princeton University (USA) (Dr I.D. Couzin) et CouzinLab of Max Planck Institute of Ornithology (Konstanz University, Germany) (Dr I.D. Couzin)

PACA (Psychologie de l’apprentissage et de la cognition animale) (Dr André Ferrara) (University of Liège)

Laboratory d’Immunology & Vaccinology (Pr Alain Vanderplasschen) (University of Liège)

Centre UMR ECOBIOP (Unité Mixte  de recherche Ecologie comportementale et Biologie des populations de poissons) INRA de Saint-Pée sur Nivelle (Université de Pau et des Pays de l’Adour), France (Dr Philippe Gaudin, Dr Agnès Bardonnet)

Laboratoire de Démographie des Poissons et hydro-écologie (LDPH) (Dr Michaël Ovidio)  (University of Liège)

Laboratoire de Morphologie Fonctionnelle (Pr. Eric Parmentier) (University of Liège)

G.R.A.S.P. (Group for Research and Application in Statistical Physics) (Pr Nicolas Vandewalle, University of liège)



Delcourt J. 2008. Structure et ontogenèse des comportements de banc chez deux poissons Cichlidés : approche quantitative par l’utilisation du vidéotracking automatisé chez Oreochromis niloticus et Pelvicachromis pulcher.  [Thèse de Doctorat]. Liège, Belgique : Université de Liège, 333p.

Delcourt J. 2003. Approche expérimentale des comportements d’anti-prédation chez le tilapia du Nil (Oreochromis niloticus) : détection et évaluation des risques de prédation par les juvéniles. [Mémoire de DEA]. Liège, Belgique: Université de Liège.

Delcourt J. 2002. Etude comparative du chant imitatif de deux espèces du genre Acrocephalus : le phragmite des joncs (A. schoenobaenus) et la rousserolle effarvatte (A. scirpaceus).  [Mémoire de licence]. Liège, Belgique : Université de Liège

Price & Grant

2016 :  Joint Holder of the Second Price QuarryLife Award BENELUX

2015 :  Price Eduard van Beneden (Société Royal des Sciences de Liège)

2009 – 2010: EGIDE grant – Tournesol Hubert Curien Bourse

2008:   First Price best poster communication to the “Measuring Behavior 2008: 6th International Conference on Methods and Techniques in Behavioral Research”, Maastricht, The Netherlands, 26-29 August 2008.

2007 – 2008 :  René Comoth –Réseau ULg Grant (Friends of Université de Liège)

2003 – 2007 :  PhD funding from FRIA (Funds for Research in Industry and Agriculture)

Press article

Watching fish with a video camera (by Frédéric Moser, in “Reflexions, Source of knowledge” ULg)