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Collective personalities: from individuals to groups, and back

Periodic Reporting for period 1 - GROUPIND (Collective personalities: from individuals to groups, and back)

Reporting period: 2015-10-01 to 2017-09-30

Many organisms, including humans, group together and perform collective actions such as birds forming coordinated flocks to evade predators, forage or roost. Some, as social insects, have evolved complex societies in which the unit of selection is not the individual, as in most vertebrates, but the colony. Yet, in both there is evidence of consistent behavioural variability among both individuals and groups. The study of collective behaviour - coordinated actions resulting in emergent properties at the group level - and the study of animal personality - between individual differences that are consistent over time and contexts - have progressed tremendously in the last two decades and are converging in their search for the link between individuality and collectivity, a fundamental and timely issue in biology. GROUPIND aims to investigate the relationship between individual personality and group personality by using insects (ants) and birds (starlings) as study organisms, both of which showing distinct collective behaviour and marked individual behavioural variability. The project will use a comparative approach to address the following objectives: (1) To characterize, also upon experimental manipulation, the composition of personalities in the group and understand how this relates to personality at the group level. Are group personalities an average of individual personalities within the group? Do they result from different distributions of individual personalities? Are there keystone individuals that exert a disproportionate influence on the group personality? (2) To understand how diversity of individual personalities contributes to decision making and to the ecological success at the group level, and how this would feed back at the individual level. By bridging two major fields of study, this project will shed new light on the ability of groups to function effectively, unravelling the consequences that personality differences can exert on social life and its evolution.
The project has been successfully implemented. Both insects (ants) and birds (starlings) proved to be valid organisms for assessing the role of individual personality on group behaviour. After a characterization phase, which revealed consistent (i.e. statistically significant repeatability) individual differences in classic personality traits such as exploration, we were able to manipulate group composition creating both homogeneous (individuals with very similar personality) and heterogeneous (one very different individual, so called « keystone », placed in a group of similar individuals) groups and thereafter to measure collective behaviour in different contexts.

Below the list of scientific papers produced so far, supervision of students, and exploitation/dissemination.

Scientific papers

Canestrelli D, Bisconti R, Carere C. (2016) Bolder takes all? The behavioural dimension of biogeography. Trends Ecol Evol 31, 35-43

Canestrelli D., Porretta D., Lowe W., Bisconti R., Carere C., Nascetti G. (2016) The tangled evolutionary legacies of range expansion and hybridization. Trends Ecol Evol 31, 677-688

d’Ettorre P., Carere C., Demora L., Le Quinquis P., Signorotti L., Bovet D. (2017) Individual differences in exploratory activity relate to cognitive judgement bias in carpenter ants. Behav. Proc., 134, 63-69

Udino E., Perez M., Carere C., d’Ettorre P. (2017). Active explorers show low learning performance in a social insect. Current Zoology, 63, 555–560

Carere C., Audebrand C., Rödel H., d’Ettorre P. Individual behavioural type influences group performance in Formica fusca ants. Behav Ecol Sociobiol (submitted)

Carere C., Mather J.A. (Eds.) The Welfare of Invertebrate Animals. Springer. Invited Volume, Planned publication: 2018

Carere C., Mather J.A. Consider the individuals: personality and welfare in invertebrate animals. In: Carere C., Mather J.A. (Eds) The Welfare of Invertebrate Animals. Springer. Planned publication: 2018

Master thesis

Celine Audebrand (2016) L'individualité chez Formica fusca joue t-elle un rôle au niveau du groupe? Master 1 Ethologie, LEEC, Université Paris 13

Florian Desigaux (2016) Individual versus group level personality in the European Starling (Sturnus vulgaris), and implications for welfare. Master 2, Applied Ethology LEEC, Université Paris 13

Celine Audebrand (2017) From individual personality to group personality: role of keystone individuals in flocks of European Starlings (Sturnus vulgaris). Master 2, Fundamental and Comparative Ethology, LEEC, Université Paris 13

Stage reports

Naomi Kotek (2016) Etude préliminaire sur la personnalité chez les fourmis Formica fusca. Rapport de Stage, LEEC, Université Paris 13

Plotine Jardat (2016) Existe-t-il un lien entre les personnalités individuelle et collective chez la fourmi Aphaenogaster senilis? Rapport de Stage, LEEC, Université Paris 13

Scientific talks

d’Ettorre P. (2016) Behavioural variation, task specialization and cognitive performance in ants. XII Congress of the International Society for Neuroethology, Montevideo, Uruguay (keynote symposium speaker)

Carere C. (2016) New challenges in the study of animal personality. LECD, Université Paris 10, 25-11-2016 (invited department seminar)

d’Ettorre P. (2017) Recognition of identity and cognitive abilities in ants. Institute of Ecology and Evolution, University of Bern, 04.04.2017 (invited department seminar)

Carere C., Audebrand C., Rodel, H., d’Ettorre, P. (2017) Personality and group performance in a social insect. XXVII Meeting Italian Society of Ethology, Calci, 18-21 June (oral talk)

Verjat A., Surreault A., Carere C., Gouat P., Rödel H. (2017) Group-level differences in a transport task emerge from individual differences in personality: a study in a small rodent Behaviour 2017, 30th July-4th August, Estoril, Portugal (poster talk)

Carere C. (2017) Animal personality: the power of the individual. V Polish Evolutionary Conference. Torun 25-28 September (invited plenary lecture)

Dissemination for the general public

Gillman S. (2016) Patterns in society can reveal economic bubbles. Horizon - The EU Research & Innovation Magazine 30 March 2016 (interview on the GROUPIND project)

Ferrari M. (2016) Bestie di carattere. Focus Extra 72, pp. 46-50 (interview on animal personality)

Carere C. (2017) Tutti in fuga! Come una folla, uno stormo, le cellule. Meet me tonight. European Researchers’ Night, National Museum of Science and Technology, Milano, 29 September (public dialogue among scientists of different disciplines: G. Scita, R. Cerbino, C. Carere, C. Sinigaglia, moderated by G. Nucera, in collaboration with IFOM, Institute of Molecular Oncology)
By bridging two major fields of study, this project will shed new light on the ability of groups to function effectively, unravelling the consequences that personality differences can exert on social life and its evolution.