Hibernation is an adaptive strategy that allows animals to enter a hypometabolic state, conserving energy and enhancing their fitness by surviving harsh environmental conditions. However, addressing the adaptive value of hibernation, at the individual level and in natural populations, has been challenging. Here, we applied a non-invasive technique, body composition analysis by quantitative magnetic resonance (qMR), to calculat...

Individual diet specialisation ( IS ) is frequent in many animal taxa and affects population and community dynamics. The niche variation hypothesis ( NVH ) predicts that broader population niches should exhibit greater IS than populations with narrower niches, and most studies that examine the ecological factors driving IS focus on intraspecific competition. We show that phenotypic plasticity of traits associated with function...

The niche variation hypothesis ( NVH ) predicts that populations with broader niches should exhibit greater between‐individual diet variation or individual specialization ( IS ) relative to populations with narrower niches. Most studies that quantify population niche widths and associated levels of IS typically focus on a single or few species, but studies examining NVH in a phylogenetically informed comparative analysis among...