Soutenance de thèse : Suzanne Bonamour du Tartre

Soutiendra publiquement ses travaux de thèse intitulés :

Breeding with seasons: Variability, heritability, and natural selection
of phenological plasticity in a wild bird

Le vendredi 22 novembre 2019 à 14h
Amphithéâtre de la délégation du CNRS 


Phenotypic plasticity – the expression by a single genotype of different phenotypes according to the envi-ronment  is ubiquitous in nature. Changes in phenology through plastic modulations are currently one of the main responses to climate change in the wild. Despite allowing adaptive and fast responses to environmental variation in the past, phenotypic plasticity may not be adaptive anymore in the new and/or extreme environ-mental conditions created by rapid global change. In this context, evolution of phenotypic plasticity could be crucial for population adaptation and persistence. One of the most studied examples of phenological plastici-ty is the variation of avian egg-laying date according to spring temperature which acts as an environmental cue in most of passerines species in temperate regions. Taking advantage of the long-term monitoring of four wild populations of Mediterranean blue tits (Cyanistes caeruleus), this thesis investigates the variability, heritability of and natural selection on phenotypic plasticity of reproductive phenology. First, a review of the influence of climate change on phenotypic plasticity highlighted the importance of potential changes in cue(s) reliability for plasticity to remain adaptive, a point we further explored in our four blue tits populations and their main preys (caterpillars), showing differences among populations from different habitats. Second, to better understand the drivers of within-individual variation of laying date phenology we evaluated how ageing af-fects plasticity of laying date in response to temperature, and revealed stronger plasticity in mature compared to young or old females. Moreover, we assessed plasticity of reproductive senescence according to the envi-ronmental quality experienced by birds during their lifetime and showed that individuals experiencing good environments age faster. Finally, to improve our knowledge of the evolutionary potential of reproductive phe-nology in this species, we estimated the heritability of laying date and implemented methods to estimate nat-ural selection on laying date and its plasticity. We showed both heritability of and selection on plasticity, we thus expect response to selection.

Phenotypic plasticity, Phenology, Laying date, Climate change, Cue reliability, Senescence, Natural selection, Response to selection, Blue tits, Wild population

Membres du jury composé de
Jane Reid, Professeur, University of Aberdeen and NTNU Trondheim Rapportrice
Marcel Visser, Professeur, Netherlands Institute of Ecology Rapporteur
Alexandre Robert, Maître de conférences, MNHN – Paris Examinateur
Ophélie Ronce, DR CNRS, Institut des Sciences de l’Evolution de Montpellier Examinatrice
Céline Teplitsky, CR CNRS, Centre d’Ecologie Fonctionnelle et Evolutive Directrice
Anne Charmantier, DR CNRS, Centre d’Ecologie Fonctionnelle et Evolutive Co-encadrante
Luis-Miguel Chevin, CR CNRS, Centre d’Ecologie Fonctionnelle et Evolutive Co-encadrant