Cooperation can be defined as a behavioural trait that is beneficial for the recipient and has been selected for this effect. One of the key questions about cooperative behaviour concerns the interplay between environment and this trait. Biparental care in socially monogamous animals is both a cooperative behaviour and a source of conflict. Several experimental and theoretical works on parental investment have confirmed plasticity (ability to change phenotype in response to changes in the environment) of parental investment on short periods in relation with social (offspring condition, partner effort) and non-social (climate, resources, predation) parameters [1]. It has also been shown that the plasticity of parental investment can lead to cooperation between parents (coordination of activities to optimize the total investment of the pair) rather than to conflict (decrease of the investment of an individual at the expense of the mate) [2, 3, 4].

However, few studies have investigated plasticity in parental investment varies within and between populations. Recent studies have shown that phenotypic plasticity has a genetic basis and can be selected [5]. As natural selection acts on inter-individual variation, the evolutionary potential of behavioural plasticity can be investigated by studying these variations. Moreover, the external environment can have a strong incidence on behavioural strategies and the fitness of individuals, and thus on the balance between conflict and cooperation.

My PhD project aims to quantify the influence of multiple environmental parameters, social and non social, on cooperative behaviour while raising young in Great and Blue tits. A second goal of my study will be to identify and measure the environmental parameters that modulate behavioural responses of parents. The questions that will be addressed during this study are the following:


  1. Nick J Royle, Per T Smiseth, and Mathias Kölliker. The evolution of parental care. Oxford University Press, 2012.
  2. Rufus A Johnstone, Andrea Manica, Annette L Fayet, Mary Caswell Stoddard, Miguel A Rodriguez-Giron-es, and Camilla A Hinde. Reciprocity and conditional cooperation between great tit parents. Behavioral Ecology, 25(1):216-222, 2014.
  3. Mylene M Mariette and Simon C Griffith. The adaptive signi-cance of provisioning and foraging coordination between breeding partners. The American Naturalist, 185(2):270-280, 2015.
  4. Karen L Wiebe. Negotiation of parental care when the stakes are high : experimental handicapping of one partner during incubation leads to short-term generosity. Journal of animal ecology, 79(1):63-70, 2010.
  5. DH Nussey, AJ Wilson, and JE Brommer. The evolutionary ecology of individual phenotypic plasticity in wild populations. Journal of evolutionary biology, 20(3):831-844, 2007.



Poster : Population variation of plasticity in parenting behaviour in blue tits.
Léa Lejeune, Aisha C. Bründl, Andy F. Russell, and Alexis S. Chaine.
ISBE -- 28 juillet-03 août 2016 -- University of Exeter (UK).

Présentation orale : Male and female helper effects on maternal
investment and adult survival in red-winged fairy-wrens.
Léa Lejeune, Martijn van de Pol, Andrew Cockburn, Marina Louter, Lyanne Brouwer. Ecology and Behaviour -- 19-23 juin 2017 -- Centre d'Études Biologique de Chizé.