Higher masseter muscle mass in grazing than in browsing ruminants.

Author(s)Marcus Clauss, Reinold R. Hofmann, W. Jürgen Streich, Jörns Fickel and Jürgen Hummel
Year Published2007
Page Numbers1-9
Size340.56 KB

Using cranioskeletal measurements, several studies have generated evidence that grazing ruminants have a more pronounced mastication apparatus, in terms of muscle insertion areas and protuberances, than browsing ruminants, with the resulting hypothesis that grazers should have larger, heavier chewing muscles than browsers. However, the only investigation of this so far [Axmacher and Hofmann (J Zool 215:463–473, 1988)] did not find differences between ruminant feeding types in the masseter muscle mass of 22 species. Here, we expand the dataset to 48 ruminant species. Regardless of phylogenetic control in the statistical treatment, there was a significant positive correlation of body mass and masseter mass, and also a significant association between percent grass in the natural diet and masseter mass. The results support the concept that ruminant species that ingest more grass have relatively larger masseter muscles, possibly indicating an increased requirement to overcome the resistance of grass forage. The comparative chewing resistance of different forage classes may represent a rewarding field of ecophysiological research.

Keywords: masseter, phylogeny, grazer, browser, morphology
Authors: Marcus Clauss, Reinold R. Hofmann, W. Jürgen Streich, Jörns Fickel and Jürgen Hummel
Journal: Oecologia

Terms and Conditions: Any PDF files provided by the GRC are for personal use only and may not be reproduced. The files reflect the holdings of the GRC library and only contain pages relevant to giraffe study, and may not be complete. Users are obliged to follow all copyright restrictions.