Geographical and Functional-Morphological Variations of the Skull in the Gray-Bellied Squirrel
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- ENDO Hideki
- Department of Zoology, National Science Museum
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- KIMURA Junpei
- Department of Veterinary Anatomy, College of Bioresource Sciences, Nihon University
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- OSHIDA Tatsuo
- Laboratory of Molecular Ecology, Department of Biology, Tunghai University
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- STAFFORD Brian J.
- Mammal Division, National Museum of Natural History, Smithsonian Institution Department of Anatomy, Howard University College of Medicine
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- RERKAMNUAYCHOKE Worawut
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Kasetsart University
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- NISHIDA Takao
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Kasetsart University
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- SASAKI Motoki
- Department of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine
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- HAYASHIDA Akiko
- Department of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine
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- HAYASHI Yoshihiro
- Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo
Abstract
The geographical variations of the skulls were osteometrically examined in the gray-bellied squirrel (Callosciurus caniceps) from the populations of Korat, Ranong, southernmost Thailand, and Terutau Island. The skull size was larger in northern population than in the southern population in the continental mainland. The zoogeographical influences of the Isthmus of Kra remained unclear, since the plots from Korat population were intermingled with those from southernmost Thailand population in the principal component charts. Although Korat population has been thought to belong to north group, we suggest that Ranong and southernmost Thailand populations may contain individuals from both north and south groups separated by the ancient Kra barrier. Terutau Island population was similar to southernmost Thailand population in skull size, although Terutau population has been isolated in the island and separated from the south group of the Isthmus of Kra. In the proportional analysis the interorbital space was narrower and the binocular sense has been well-developed in Terutau population. It suggests that this population has been highly adapted to arboreal behavior. In contrast, the skull with larger interorbital space was more adaptive for terrestrial life in Korat population. The canonical discriminant analysis could clearly separate the four populations in the scattergrams of discriminant scores.<br>
Journal
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- Journal of Veterinary Medical Science
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Journal of Veterinary Medical Science 66 (3), 277-282, 2004
JAPANESE SOCIETY OF VETERINARY SCIENCE