Abstract
Japalura polygonata is an arboreal agamid lizard native to the subtropical East Asian islands. Recently this lizard was found in large numbers in a coastal hilly area of southeastern Kyushu, which represents the temperate part of Japan. Morphological examination of the specimens collected revealed that this lizard assemblage belongs to the nominotypical subspecies (J. p. polygonata), which is endemic to the central Ryukyus. Specimens collected in the summer of 2005 included females with oviductal eggs. Another sampling carried out in the spring of 2006 yielded juveniles that supposedly hatched the previous summer and successfully overwintered. These, along with information from inhabitants and the local newspaper, strongly suggest that in the present area this subtropical tree lizard has already established a breeding population. The impact of this exotic species on the native ecosystem may be of substantial conservation concern.