ECR Spotlight – Agnès Lewden

Agnès Lewden

How did you become interested in biology?

I grew up in the countryside, which gave me the opportunity to interact with wildlife. At the age of 10, I got frustrated not to be able to learn more so I started to do ‘scientific’ experiments on my own like counting the number of nestling provisioning per hour in swallows and testing food choice protocols on my rabbit. I watched every animal documentary I could and took notes because I wanted to know everything about species around the world. I always hoped that one day I'd be one of the scientists I saw in those documentaries, and today I'm very close to my dream.

Describe your scientific journey and your current research focus

I started my research career with a Master's degree at the University of Québec in Rimouski (Canada) investigating cold acclimatization in Black-capped chickadees (Poecile atricaipillus). At the end of 2011, I was selected for the French scientific station Dumont D'Urville (Antarctica). Thus, I spent 15 consecutive months in the field (two summers and one winter) following the breeding season of eight bird species including two penguins species (Pygoscelis adeliae and Aptenodytes forsteri) and one marine mammal.

Before starting my PhD, I first completed a diploma during which I initiated the project that I then pursued during my PhD. I then obtained a 3 year doctoral fellowship funded by the French Ministry of Education and Research to study the thermoregulation processes in king penguins (Aptenodytes patagonicus) in the function of nutritional states and environment (i.e. in water and ashore).

I spent the next 3 years as a post-doctoral fellow at the University of Leeds (UK) working on the heat production during flapping flight in lovebirds (Agapornis personatus) flying in experimental conditions.

In 2022, I obtained international post-doc fellowship funding from ISblue to work at the University of Brest (France). My current projects aim to (1) measure the potential heat stress in Sub-Antarctic and Antarctic penguin species, (2) investigate the redistribution of abiotic resources driven by breeding seabirds from the land to the coast and (3) investigate the importance of snow surface cover for Arctic passerines.

How would you explain the main findings of your paper to a member of the public?

Imagine going jogging in a ski suit. It's a bit like what penguins go through during their moult. Every year when they are back on land, they have a small window to renew their entire plumage. During this period, there is no more swimming and no more foraging; all their energy is invested in producing new, dense, waterproof feathers that enable them to live all year round in the water, maintaining their body temperature at 38°C.

Still, living in Antarctica demands they maintain insulation at all costs. That's why new feathers grow underneath the old ones to maintain body insulation. Could penguins get too hot when they are producing more heat to synthetize new feathers and wearing a double coat?

To answer this question, we measured body surface temperatures in captive gentoo penguins (Pygoscelis papua) during moult. Our results show that, while the insulation of the trunk increased, penguins dissipated more heat through the less insulated areas of their bodies, meaning the beak, flippers and feet. These results obtained in a controlled environment raise an important question: could penguins face an additional thermal stress when they moult in an environment impacted by global warming?

What is the most important piece of equipment for your research, what does it do and what question did it help you address?

The most important piece of equipment for my research is undoubtedly my thermal imaging camera. It enables me to study the thermoregulation of my study models non-invasively, which is an undeniable advantage. Thermal imaging is a friendly technology accessible to all, enabling you to easily visualize warmer and colder areas. However, beyond its apparent simplicity, it requires rigor in data collection and image analysis. To make the most of this promising technology, we still need to understand the relationships between body surface temperatures visible in thermal imaging and internal temperatures of individuals. I'm currently investigating this relationship both under controlled conditions and in the wild.

What is your favourite animal, and why?

Surprisingly, my favourite animal is not penguins although I do admire their diving capacity and I am always amazed by their hydrodynamism, their powerful feet, their dense plumage that looks like fish scales on the flippers. I've been lucky to observe these amazing birds during hours working in the gorgeous Antarctic environment. But no, my favourite animal is the aardvark (Orycteropus afer). Being French, it's impossible for me to pronounce its English name, but I really love its Latin name. It's certainly not Africa's most emblematic mammal, and it's still largely unknown to the general public, but I like its debonair air, long ears, long nose as much as its uniqueness and discretion. Of course, the thermoregulation processes of this species are fascinating too and like many others, this species is threatened by climate change.

What is one thing about you that others might find surprising?

Ironically for a biologist studying thermoregulation, I am always cold. That's why working in cold environments is perfect for me: I can be cold in complete serenity without anyone being surprised.