Abstract
We constructed a butterfly database using records collected by citizen scientists during the period from 1923 to 2008 in the three westernmost wards of Tokyo, Japan. Using the database, we examined the temporal change in the butterfly fauna in the area and analyzed the contribution of nine ecological traits to the difference between two periods: 1923-1960 (past) and 1982-2008 (recent). Of the 66 species recorded in the past, 16 species had disappeared in the recent period. Logistic regression showed that the disappearance was significantly associated with three ecological traits: univoltine (P<0.01), feed plant specialist (P<0.05), and inability to utilize cultivated plant species as feed plants (P<0.01). By contrast, all six species newly recorded in the recent period were bivoltine or multivoltine, and four of these species utilized cultivated plant species. The newcomers were species that were known to have recently expanded their distributions in Japan, probably due to warming, the heat-island effect, and global climate change. Our results indicated that this type of database is useful for revealing temporal trends in rapid butterfly faunal change and for analyzing factors affecting the change.
