Diet, physiology and environment of the cave bear: a biogeochemical study.

In the last years, biogeochemical studies based on stable isotope analysis on fossil remains of cave bears were conducted by different research groups in order to elucidate some of the still open questions of the palaeobiology of this extinct species. In particular, questions about the diet of the cave bears were intensively addressed. Published results, however, give an unclear view if isotopic analysis are not considered in connection with the insights from other fields of research. However, the isotopic signatures cannot be interpreted straightforward and alone. It is necessary to take into account other data such as the phylogeny, the morphology, and the particular physiology, in a well-known chronological framework, to get a clear picture of the palaeobiology of an extinct species. In this work we review the available isotopic data coming only from well-contextualized cave bear sites, and explore how the climate can influence the physiology of the cave bears through their hibernation length and, in turn, the isotopic signatures registered in their bones