My group studies the developmental plasticity and fitness consequences of behavioral and life history variation seen within natural populations of several animal species. We are also interested in understanding how this variation feedbacks into population dynamics and for this matter conduct experiments on whole populations and design new population dynamic models. You can find updated informations on our ongoing research projects in the home page. Do not hesitate to contact me if you wish to join one of these research projects!
Extinction mechanisms in small populations
The massive extinction of species and populations is a major concern today. To solve this crisis, we need conservation programs dedicated to the preservation of small populations that are particularly vulnerable. One method widely available to guide such conservation programs is Population Viability Analysis (PVA) – a tool relying on stochastic population theory to estimate the future size and risk of extinction for small populations. However, our understanding of the dynamics of small populations is quite limited and the predictive ability of PVA has been questioned by several researchers. In my group, we challenge the predictive ability of PVA methods by linking population biological theory with experimental studies of extinction dynamics. Our overall aim is to gain better knowledge of the dynamics of small populations and the mechanisms leading to population extinction. Our model systems are experimental populations of the common lizard (Lacerta vivipara), the root vole (Microtus oeconomus) and the bank vole (Myodes rufocanus).
Key recent reference: Mugabo, M., Perret, S., Legendre, S. and J.-F. Le Galliard. 2013. Density-dependent life history and the dynamics of small populations. Journal of Animal Ecology 82(6):1227-1239.
Life history variation
Life history results from age and sex dependent variation in reproduction effort, survival and growth strategies. In my group, we study several important life history problems, such as the ontogenic basis of sexual dimorphism in morphology and coloration, the costs of reproduction, the mechanistic basis and fitness consequences of interindividual variation in locomotor capacities and the determinants of early variation in survival. In the recent past, we have been investigating cohort effects due to delayed life history consequences of environmental variation using both natural and experimental populations of the common lizard. We used these data to parameterize physiologically structured population models of the common lizard.
Key recent reference: Bleu, J., Le Galliard, J.-F., Fitze, P., Meylan, S., Clobert, J. and M. Massot. 2012. Reproductive allocation strategies: a long-term study on proximate factors and temporal adjustments in a viviparous lizard. Oecologia 171(1):141-151.
Evolutionary ecology of social and non social behavioral traits
We are interested in understanding interindividual variation in social behaviors (altruism), mating strategies (mate choice and sexual conflicts) and individual behavioral profiles (activity, sociality, boldness, agression). Our approach is truly interdisciplinary and involves mathematical modeling, field study of variation in behavioral traits and experimental studies of natural and sexual selection on behavioral traits. Our recent studies have adressed complex issues such as how interindividual variation in behaviour correlate with variation in physiology.
Key recent reference: Le Galliard, J.-F., Paquet, M., Cisel, M. and L. Montes-Poloni. 2012. Personality and the pace-of-life syndrome: variation and selection on exploration, metabolism and locomotor performances. Functional Ecology 27(1):136-144.
Evolutionary ecology of dispersal
Dispersal is a key behavior that influences importantly ecological and evolutionary dynamics. Our current understanding of this behavioral trait suggests that multiple selective pressures are involved in its evolution. However, crucial tests for the role of these selective forces in shaping dispersal strategies are rare. We also lack a clear understanding of the life history correlates of dispersal within and between species. In my group, we use experimental approaches to investigate the plasticity of this behavior, as well as the potential selective pressures acting on dispersal. Our model systems are two vertebrate species - the common lizard (Lacerta vivipara Jacquin) and the root vole (Microtus oeconomus Pallas) - and the springtail Folsomia candida. Our past results indicate that family dynamic, and in particular competition among relatives, can have a strong effect on dispersal behavior. More recently, we have shown that intrasexual competition among females and female dominance are key determinants of the settlement success in a small rodent. We are pursuing these lines of research in collaboration with other research groups in France.
Key recent reference: Stevens,V., Whitmee, S., Le Galliard, J.-F., Clobert, J., Böhning-Gaese, K., Bonte, D., Brändle, M., Dehling, D., Hof, C., Trochet, A. and M. Baguette. 2014. A comparative analysis of dispersal syndromes in terrestrial and semi-terrestrial animals. Ecology Letters 17(8): 1039-1052.
Applied conservation biology
We are currently using our knowledge of population demography and evolutionary ecology to gather demographic data that should help managers to implement appropriate conservation strategies. One such project is a demographic study of a small, threatened population of the Orsini's viper (Vipera ursinii ursinii) monitored by Jean-Pierre Baron since 1979. Another project was a geographic survey of abundance, genetic and phenotypic distribution of lizard species in the Seine & Marne department, for which we designed standardized sampling protocols.
Key recent reference: Baron, J.-P., Le Galliard, J.-F., Ferrière, R. and T. Tully. 2012. Intermittent breeding and the dynamics of ressource allocation to growth, reproduction and survival. Functional Ecology 27(1):173-183.
Left side: photograph of V. ursinii ursinii by J.-P. Baron at Mont Ventoux (France)