Bergmann meets Scholander: Geographical variation in body size and insulation in the koala is related to climate

Abstract

Aim: Body size often varies clinally, with dominant explanations centred on how body size influences heat exchange (e.g. Bergmann's rule). However, for endotherms, pelage properties can also dramatically alter heat exchange - a point emphasized by Scholander in the 1950s but which has received little attention in biogeographical analyses. Here, we investigate how geographical variation in both body size and fur properties of the koala (Phascolarctos cinereus) is related to climate. Location: Eastern Australia. Methods: We measured head length and fur depths of koala museum specimens from across its geographical range, and quantified the relationship between fur depth and insulation. We used ..