Research Interests

Natal dispersal, socially acquired information and personality traits

 

My work relates to socially acquired information and personality traits in common lizard (Lacerta vivipara). With a two-scale approach (population and individual experiments), my studies aim to demonstrate the existence and the mechanisms of social information and personality traits as well as the implications for natal dispersal. Actually, “should I stay or should I go?” is a fundamental question facing any candidate for dispersal, as dispersing without outside information has major costs. Most studies on this topic have concentrated on risk-reducing strategies (e.g. exploration) developed after leaving the natal habitat. My works demonstrated that immigrants are a source of information about surrounding populations (e.g. about surrounding population densities), and may have a major effect on natal dispersal. Therefore, information about surrounding populations might be acquired before leaving. During my PhD thesis, I also focused my research on lizard personalities. I investigated the existence of social personalities and their implications in natal dispersal: While ‘social’ lizards seek habitats with many neighbours, ‘asocial’ lizards tend to flee these habitats. Therefore, social personalities exist in common lizards and strongly affect the selection of suitable habitats and the fitness outcomes.

 

Ecophysiology of the stress-response

 

In response to stressful conditions, animals modify their behaviour and physiology to avoid or balance negative effects of stress. Corticosterone is therefore an important hormone of the stress response that regulates physiological processes and modifies animal behaviour. My works aim to demonstrate that the stress-response mediated by corticosterone is an adaptive mechanism in common lizard (Lacerta vivipara). I experimentally showed that corticosterone increases energy expenditure, daily activity, food intake, males survival and it modifies the behavioural time budget. My studies suggest that corticosterone promotes behaviours that reduce stress and that corticosterone per se does not reduce but directly or indirectly increases longer-term survival. I also investigated the roles of corticosterone in carotenoid-based coloration, oxidative stress and immune responses (see below).

 

Carotenoid-based coloration, oxidative stress and immune response

 

Carotenoid-based coloration is an ubiquitous signal of individual quality that is largely environmentally determined. Current studies suggest that it is an honest signal providing information about animals health and condition. Indeed, carotenoids are also used for immune function and for antioxidant activity, leading to a trade-off between ornamentation and health for limited carotenoids. I am interesting in the physiological aspects of this trade-off and of the maintenance of exaggerated coloration, using both the common lizard (Lacerta vivipara) and the zebra finch (Taeniopygia guttata) as model systems. I investigate physiological modulations of carotenoid-based colorations (i.e. corticosterone and immune activation) and the consequences on health and condition (i.e. oxidative stress and body condition). At the same time I am as well trying to understand why common lizards with high blood corticosterone levels show redder belly coloration and why corticosterone may have an adaptive role in the trade-off between coloration and immune response in zebra finches.

 

Current collaborations

 

Experimental ecology centre (USR 2936, Toulouse, France)

Jean Clobert (http://www.biologie.ens.fr/ecologie/comportement/clobert/index.fr.html)

 

Global changes and adaptive processes

(University Paris 6, France)

Sandrine Meylan (http://ecologie.snv.jussieu.fr/smeylan)

Jean-François Le Galliard (http://jf.legalliard.free.fr)

Murielle Richard (http://ecologie.snv.jussieu.fr/mrichard/)

David Laloi (http://ecologie.snv.jussieu.fr/dlaloi/)

 

Ecologie des Hydrosystèmes Fluviaux

(Université Claude Bernard - Lyon 1, France)

Yann Voituron (http://umr5023.univ-lyon1.fr/index.php?pid=266&lang=fr)

 

National Museum of natural sciences (Madrid, Spain)

Patrick Fitze (http://www.mncn.csic.es/P.S.Fitze_Homepage.htm)

 

University of Bourgogne (Dijon, France)

Bruno Faivre (bruno.faivre@u-bourgogne.fr)

Gabriele Sorci (Gabriele.Sorci@u-bourgogne.fr)

 

Department of Environmental Science and Policy (Davis, USA)

Andrew Sih (http://www.des.ucdavis.edu/research/sihlab/)

Sean Fogarty (spfogarty@ucdavis.edu)

Kelly Smith ( klsmithbio@gmail.com)

 

Umea University (Sweden)

Tomas Brodin (tomas.brodin@emg.umu.se )

Julien Cote