The release of pet raccoons (
Procyon lotor), a North American native, has resulted in the species becoming naturalized in most of Japan's prefectures. When state and local governments implement wildlife management programs including an alien species, it is important to know the size of the target population to be managed. The population estimation for an alien species over an extensive area, such as raccoon, has not yet been developed, In this study, we developed a raccoon population model using two statistical methods: a generalized linear model (model 1) and a generalized linear mixed-model (model 2) were analyzed using geographic information system (GIS) data based on
harmful animal extermination data, land-use data, and satellite data. The explanatory variable of the natural environment was elucidated by a stepwise approach in both models. Based on the two models, the population distribution of raccoons within Osaka Prefecture was estimated using GIS. Model estimates were highly correlated with actual data on the presence of raccoons (model 1:
r = 0.898, model 2:
r = 0.898). Model 1 estimated the size of the raccoon population in Osaka Prefecture to be 2,836 individuals (95% CI = 2,350-3,418) and model 2 estimated it to be 2,836 individuals (95% CI = 2,289-3,515).
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