Invasive alien raccoons (Procyon lotor) naturalized 36 prefectures certainly and temporal invasions were recorded in all 47 prefectures in Japan. Raccoons have negative impacts such as agricultural damage, transmission of zoonotic infection, competition with native species and predation on native species.

Pest control harvest was conducted in early phase of countermeasures, but this method is no more than a stopgap measure. Then we made a scientific eradication program based on the simulation of population development using some reproductive parameters such as pregnancy rate (66% in yearlings and 96% in adults) and litter size (3.6 in yearling and 3.9 in adults). This simulation showed that in Central Hokkaido where estimated raccoon population was 3000, we had to capture 2000 raccoons to decrease raccoon population. Unfortunately we couldn’t accomplish numerical target yet due to budget shortfall.

But it also became clear by model study in Hokkaido that regional cooperation afforded the key to raccoon control campaign, and we could keep raccoon population low revel with less effort. In some region where intensive trapping campaign conducted, agricultural damage and population density showed a downward tendency.

Current capturing method using live cage traps is not cost effective in low population density areas. Development of effective control technologies at low population density is a hot issue.