Abstract
The raccoon (Procyon lotor), one of the invasive alien species in Japan, has caused a serious impact on human life and the ecosystems. Formerly, since the late 1980s, feral raccoons have reportedly been expanding their habitats from the eastern part of Kanagawa Prefecture including Kamakura and the Miura Peninsula. However, recent investigations have revealed new distribution in the western part as well. In the year 2004, we conducted detailed researches into their recent occurrence and distribution out there by following their footprint tracks and gathering information in the relevant regions. Our findings are as follows: as is shown on a grid map of Kanagawa Prefecture divided into 452 blocks (2 x 2.5 km each) including in 99 blocks for our research, many footprints were observed on localities dotted over 12 blocks, while some raccoons had been witnessed alive in 5 blocks, as we confirmed by inquiry. Evidence of raccoon distribution was newly found in a total of 15 brocks in the western part of the prefecture. In addition, we heard of a few other raccoons being kept in private residences. Previous researches indicated that the density of feral raccoons was relatively higher in the eastern areas. By contrast, the present study suggests that the feral raccoons are widely expanding their habitats to the western areas, based on our latest data that point to the occurrence of the feral raccoons in some areas lying west of the Sagami River.
