Decline and conservation of butterflies in Japan

Abstract

Japanese lepidopterists so far have not defined their strategies to counter the decline of butterfly fauna in their country, although extinctions have so far been restricted to local populations. National and local government policies are to simply promulgate protective regulations. In most cases this means nothing more than the prohibition of collecting and has proved ineffective in reversing the rapid decline and extinction of butterfly populations. The existence and significance of the Red Data Book, currently in preparation in Japan, is as yet not widely acknowledged. However, a volume of collected papers on the history of the decline and protection of Japanese butterflies has been published by the Lepidopterological Society of Japan. It shows that traditional agriculture and silviculture practices in Japan contributed to the dynamic succession of deciduous and nondeciduous broadleaf forests (the latter being the laurisylvae) and maintenance of various types of open fields and meadows, all much needed habitats for the survival of a butterfly fauna with high biodiversity. In the preagricultural wilderness, this continuing dynamism was probably effected by forest fires, typhoons and floods. Fire, wind, water, and traditional culture historically served as protective agents for butterflies, rather than the formal prohibition of collecting. *1 Isolated populations. *2 Impoverishment of woodlands, increase of orchards, spraying, invasion of hikers, construction of a golf course are mentioned. *3 No change of population density before and after designation as Tennen Kinenbutu. *4 The population had declined prior to the designation of Tennen Kinenbutu. *5 The population decline has not stopped after the designation of Tennen Kinenbutu. *6 The reason may or may not be due to the putative overcollecting. *7 Used to be an unusually large population. Foodplants are plenty after some modification of habitat due to sightseeing developments. *8 Foodplants still remaining. *9 Citizens' activities for protection, but population perished after the designation of Tennen ^ Kinenbutu . *10 Foodplants were planted by citizens and school children. The local government and collectors have collaborated for restoring the population. One of the model cases of conservation.