*Current address: Department of Ecoregion Science, Laboratory of Wildlife Conservation, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509, Japan.
Correlations between feeding type and mandibular morphology in the sika deer
Article first published online: 21 MAR 2007
Journal of Zoology
Volume 272, Issue 3, pages 244–257, July 2007
How to Cite
Ozaki, M., Suwa, G., Kaji, K., Ohba, T., Hosoi, E., Koizumi, T. and Takatsuki, S. (2007), Correlations between feeding type and mandibular morphology in the sika deer. Journal of Zoology, 272: 244–257. doi: 10.1111/j.1469-7998.2006.00264.x
- Issue published online: 21 MAR 2007
- Article first published online: 21 MAR 2007
- Received 28 June 2006; accepted 5 September 2006
- dietary adaptation;
- microevolutionary levels;
- molar durability;
Morphological comparisons of the sika deer Cervus nippon mandible and molars were conducted between two (northern and southern) Japanese subspecific lineages and among local populations of different (‘grazer’ or ‘intermediate feeder’) feeding types. The northern lineage showed greater M1 breadth, M3 hypsodonty and mandibular corpus height than the southern lineage. Such differences were not observed between the ‘grazer’ and ‘intermediate feeder’ populations of the northern lineage. However, a northern population, which inhabits a particularly harsh environment (Kinkazan Island), had the largest values of relative molar size and hypsodonty, although this was not statistically significant. These results imply that, in the Japanese sika deer, the selective pressures acting on the current ‘grazer’ populations are not strong enough to bring out noticeable adaptive change in molar size and hypsodonty, but adaptive change in these traits may occur in an environment that promotes excessive molar wear, more than that seen in the current sika deer habitats of Japan. Combined with what is known of the Pleistocene history of the sika deer, we infer that the ancestral population of the northern Japanese lineage likely acquired their relatively larger and more hypsodont molars in an extremely harsh environment during the last or previous glacial periods.