Testing a butterfly commonness hypothesis with data assembled by a citizen science program “Tokyo Butterfly Monitoring”

Abstract

AbstractWe tested a hypothesis regarding species commonness using a database compiled by a citizen science program called “Tokyo Butterfly Monitoring.” The data used were more than 34,000 butterfly records, which were cleansed through expert check after posted by monitoring participants from 2009 to 2017. We hypothesized that butterfly species with multiple annual reproductive cycles and food plants common in city environments are more common and would have more monitoring reports. The generalized linear mixed model (GLMM) analysis revealed significant effects of including “cultivated plants” in the larval food menu and “multivoltinism” on the number of individual species reported, which was compatible with the hypothesis. The species with the most records (12% of all records among 90 species) was Zizeeria maha, which reproduces 5–6 times annually and relies on Oxalis corniculata, a small weed common in urban open spaces. Argyreus hyperbius, a southern species that was very rare before the 1990s, ranked third in the current data. Its major host plant is a common garden plant, the pansy, which grows in most gardens and green spaces. The data collected by the monitoring program appear to represent the status of the butterfly community in Tokyo, a megacity subjected to rapid environmental changes.