イノシシ, イノブタ飼育とそれらの野生化の現状

抄録

To analyze the status of wild boar (Sus scrofa), crossbred of pig×wild boar farming, and those feral populations, a written questionnaire was sent to 47 prefectural government offices, 679 branches of Dainippon Ryoyukai (Hunters Club) and 42 farmers. A verbal survey was also conducted on farmers in Gunma, Wakayama, Hokkaido, and Aomori prefectures. Breeding farms of wild boar and crossbreeds existed in 30 (63.8%) and 22 (46.8%) prefectures, respectively. The number of farms trippled between 1955 and 1964. It was the highest in the 1980s and the most popular motivation was to attract tourists. Feral crossbreds have been discovered in 36 prefectures (76.6%). The sources of feral animals were mostly unknown (69.8%). However, 0.9% of feral animals were reported to have been released intentionally. Almost half of the hunters (43.3%) surveyed responded to a question concerning their opinion of feral animals and they agreed to eliminate the animals. 23.0% welcomed them as hunting resources. Breeding was regarded as an industry that reinvigorated the local economy in Wakayama and Gunma prefectures. Delay of counter measures caused the feral crossbreed population to survive in Hokkaido.