Distribution and possible distribution route of the forest green tree frog (Rhacophorus arboreus) in Hakone, Kanagawa Prefecture, Japan

Abstract

The endemic species Rhacophorus arboreus (Anura: Rhacophoridae) is widely distributed through main island of Japan, but it has always been considered as rare in Kanagawa Prefecture. The first records of this species of Kanagawa Prefecture, in a limited area, date from 1983. This study is the first report of Rhacophorus arboreus from Hakonetown, in the western part of the Prefecture. In Hakone-town this species was first recognized from the Kojiri area, Shirayuri-dai-enchi, near Lake Ashinoko in 2005, and it has expanded its distribution toward the Northwest, Sengoku-hara, from 2009 onwards. There are three possible centres of origin for the Hakone-town population: Nagao, Gotenba-city, Shizuoka Prefecture; Mt. Kintoki, Minamiashigara-city; and Yugawara-town. Of these three, Nagao, Gotenba-city is closest to Hakone-town and the species may have extended its range from Nagao to the Kojiri area of Hakone-town.