Last Glacial and Holocene Land Mammals of the Japanese Islands: Their Fauna, Extinction and Immigration

Abstract

This paper concisely describes the land mammal faunas of the last glacial period and Holocene separately for the three biogeographic regions comprising the Japanese Islands (Hokkaido, Honshu-Shikoku-Kyushu and the Ryukyu Islands). It also outlines the extinctions and immigration of land mammals during the periods. In Hokkaido, the fauna of the last glacial period is represented only by a few extinct large mammal species. It is inferred that the Mammoth Fauna immigrated from eastern Siberia into Hokkaido during this period. The large mammal species of the last glacial period became extinct possibly by the beginning of the Holocene. The Holocene fauna of Hokkaido is almost idenfical with its present-day fauna, and no mammals immigrated into Hokkaido during the Holocene. In Honshu-Shikoku-Kyushu, the last glacial fauna is predominated by extant species now distributed in this region, and contains several extinct species as well as several extant species now exotic to this region. The extinct and exotic species seem to have become extinct between ca. 20,000 and ca. 10,000yrsBP in radiocarbon age. During the last glacial period, few elements of the Mammoth Fauna immigrated into Honshu-Shikoku-Kyushu from Hokkaido. Such limited immigration is inferred to have occurred through temporary ice bridges formed across the Tsugaru Stait instead of a stable land bridge. In Honshu-Shikoku-Kyushu, the Holocene fauna is almost identical with the present-day fauna, and no mammals immigrated into this region during the Holocene. In the Ryukyu Islands, the last glacial fauna is of insular type, and its main elements including middle- and small-sized deer became extinct possibly by the beginning of the Holocene. No mammals immigrated into the Ryukyu Islands during the last glacial period and Holocene.