I conducted my PhD in Ecophysiology at the  University of Strasbourg (2010-2013), working on the relationships between mitochondrial function, oxidative stress and animal life histories.  As a side-project of my PhD, I demonstrated that avian red blood cells possess functional mitochondria (Stier et al. 2013 Front. Zool.). Building on this finding, I developed collaborations with the French Polar Institute (2013-14) and the University of Aberdeen to use avian red blood cells to study mitochondrial function in non-model and wild animals. I then moved to the University of Angers for a Research and Teaching position (2014-2015), where I was in charge of teaching Animal Biology and Ecology. I developed a research project linking environmental constraints to accelerated ageing in a reptile species. I was then able to secure a Marie Curie fellowship (2016-17) to work as a Research Fellow at the University of Glasgow on the impact of pre-natal environmental conditions on ageing rate, using Japanese quail as a model species. I moved to the University of Turku in 2018 where I work as a TCSM Research Fellow (2018-2021). I am investigating the importance of early-life hormonal exposure (stress and thyroid hormones) in determining mitochondrial function and telomere dynamics during development and later in life, using wild birds (king penguin and passerine species).