Leszek Rychlik and co-authors from Portugal assessed the use of an external heat source (basking) in the thermoregulatory strategies of three shrew species. Shrews were tested in a terrarium where they had access to a heat rock which could be turned off (cold) or on (heated). In accordance with authors’ predictions, Crocidura russula (the most southern and cold-sensitive species) spent significantly more time on the heated rock than C. suaveolens (that inhabits mainly central Europe), whereas Sorex araneus (most northern species adapted to a Palearctic climate) spent the shortest time on external heat source. In fact, only a quarter of S. araneus individuals spent longer time on the heat rock, which suggests this thermoregulation strategy is not generally adopted by this species, but may be rather associated with some individual personalities. The study demonstrates for the first time basking behaviour in shrews and shows that shrew species use external heat sources for thermoregulation according to their sensitivity to cold.
The paper is available at: https://doi.org/10.1016/j.jtherbio.2022.103193