Patterns of distribution in Japanese land mammals

• Published in: Transactions of the American Fisheries Society
• Main Author: DOBSON, MIKE
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1994
• Subjects: Sakhalin; Tundra
• Online Access: http://dx.doi.org/10.1111/j.1365-2907.1994.tb00137.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2907.1994.tb00137.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2907.1994.tb00137.x

Abstract Distribution patterns among the terrestrial mammal species of Sakhalin and the main islands of Japan are shown to fall into 12 clear groups. The most fundamental distributional break (Blakiston's Line) is that separating Hokkaido and Sakhalin to the north, with their boreal fauna typical of northern Eurasia, from ‘Hondo’ (Honshu, Shikoku, Kyushu) to the south, which demonstrates a high degree of endemism and supports a small number of Indo‐Malayan elements. Distribution patterns may be explained by considering the Quaternary geohistory of the area, particularly the formation of land bridges and the changes in climatic conditions during this period. A dynamic classification based upon origin of the fauna recognizes seven categories, although on evidence currently available the allocation of some species to categories is not yet possible. Hondo underwent two main periods of land bridge connection to the Asiatic mainland. The first, prior to the Pleistocene, allowed immigration of forms which have since developed into distinctive elements of the endemic fauna (‘Old Hondo Endemics’). The second, during the Middle Pleistocene, brought in widespread Palaearctic species as well as components from South‐East Asia (‘Early Colonists’), some of which have since undergone vicariant speciation (‘New Hondo Endemics’); it also allowed several of the Old Hondo Endemics to extend their range to the mainland and Hokkaido (‘Expanding Hondo Endemics’). Sakhalin and Hokkaido have been more intimately connected to the mainland (most recently until less than 10 000 years ago), such that endemism is very restricted. Species groups here are the ‘Late Colonists’, cold‐adapted tundra species which expanded with the glacial advances, but which are now restricted in distribution, and ‘Recent Colonists’, postglacial forest species which recolonized before the severance of land bridges. Moving the other way were ‘Expanding Northern Endemics’, which arose in Hokkaido or Sakhalin during the last glacial and colonized the adjacent ...