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Accueil > Ecophysiology and phylogeny of sleep states

Ecophysiology and phylogeny of sleep states


  • Paul-Antoine Libourel (PI)
  • Baptiste Barrillot (PhD)
  • Gianina Ungurean (PhD)
  • Sébastien Arthaud (Support staff)


Reptiles; Birds; Evolution; Adaptation; Ecology


All animals sleep, meaning that this  universal “simple” state appeared early in the evolution and was conserved over millions of years of natural selection. This suggests that sleep may serve a core function. But, what function? Or what functions? Is the role of sleep the same for each species?

One way to understand why animals sleep, is to look at the diversity of the sleep phenotypes across species with different morphologies, life styles, diets, and ancestry and try to make parallels, comparisons, and correlations. Another way to tackle this function, is to study its plasticity in natural conditions. Indeed, by understanding how the environmental pressures, like predation, climate, resource availability or sexual partners may modify sleep and its expression, we will have a better understanding of the tradeoffs made by animals between sleeping and being awake.

Our current projects tend to give us a broader picture of sleep states, by studying how the evolution has shaped this universal and necessary behavior. To do so, we work with various animal models (mammals, birds, non-avian reptiles, amphibians and fishes) in lab and field. We use custom light weight telemetric devices and bio-loggers able of recording during multiple days, the physiology, the behavior, the metabolism and the brain activity of freely running, flying and swimming species.

On-going projects

  • Characterizing the evolution of REM sleep by studying its expression in non-mammalian species;
  • Description of the variability in sleep states expression through the animal kingdom;
  • Revealing the animal strategies to sleep when they have to be awake;
  • Development of new techniques to study sleep in lab and fields.



  • Anthony HERREL, FUNEVOL, UMR 7179, National Museum of Natural History, Paris, France
  • Won Young LEE, Korean Polar Research Institut, South Korea
  • John LESKU, Ecophysiology Group, La Trobe University, Australia
  • Niels RATTENBORG, Avian sleep Group, Max Planck Institut for Ornithology, Germany