The process of introducing, establishing and extending a raccoon population in Aichi and Gifu Prefectures in Japan was determined by analyses of newspaper articles and interviews with local government officials and residents. In 1962, 12 raccoons escaped from the Japan Monkey Center in Inuyama City, Aichi Prefecture. Thereafter, residents observed raccoons sporadically around Inuyama City and the neighboring Kani City, Gifu Prefecture in the late 1970s when the raccoon pet boom started. Later, in 1982, a person living in Kani City released approximately 40 raccoons. Information of raccoons increased as they dispersed to neighboring cities and towns. One of the possible reasons for the extension of raccoon distribution was the construction of golf courses, roads and a housing site. Finally, a raccoon population was established on the hills between Aichi and Gifu Prefectures, and it is expected to spread to the southeast areas of the hills. To decrease the introduced raccoon population, management of their food resources in the artificial environment, namely, fodder and garbage, and management of attics and sheds as their dens will be effective.

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Skinfold thicknesses of 72 Japanese macaques were measured at four points (triceps, biceps femoris, subscapula, and abdomen) by using three kinds of devices: a sliding caliper, a handy skinfold caliper (fat-o-meter®), and an Eiken-shiki skinfold caliper. Measurements by sliding caliper were much smaller (56.7-72.9%) and had larger variances than those by the other devices. Correlations were found between skinfold thicknesses measured by these three devices. Measurements by handy skinfold caliper were strongly correlated with those by Eiken-shiki skinfold caliper. These results suggested that skinfold thickness measured by handy skinfold caliper can be useful as an index of nutritional status in Japanese macaques.

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