Assessing the impact of climate fluctuations on hibernation phenology using novel dental biomarkers

Many heterothermic mammals exploit multi-day torpor (i.e. hibernation) to face harsh climates.

The timings and the regulations of this process are controlled and influenced by several intrinsic and extrinsic factors such as e.g. the circannual biological clock of the animal, the day-length, the spring temperature, the snow-melt date. Yet, how these animals answer(ed) global climate changes is still a matter of debate.

With the AROUSE project I will examine the hibernation timing and the bone elemental metabolism of small mammals from a new unexplored perspective, by analyzing well-dated fossil and modern hibernating rodent teeth straddling the last glacial-interglacial cycle.

Specifically, I will exploit the enamel incisor micro-chemistry (high-spatially resolved elements and isotopes), histomorphometry and proteomics of geographically-constrained Alpine marmots to: 1) precisely measure sex-specific hibernation length; 2) investigate metabolic changes in relation to (paleo)climate seasonal fluctuations; 3) unravel dental enamel secretion and mineralization behavior during winter torpor; 4) search for specific dental chemical biomarkers of hibernation, transferable to other disciplines.

For the first time, this project will provide a robust tool for the retrospective study of hibernation events in dental specimens, allowing to deepen our knowledge about hibernation plasticity but also to possibly investigate the evolutionary trajectories of torpor in deep-time.

AROUSE will also help to understand how marmots adapted to secular climate variations, possibly forecasting the effects of global warming on modern hibernating mammals.