Trends and Progress in Studying Butterfly Migration

Abstract Background Several hundred butterfly species show some form of migratory behaviour. Here we identify how the methodologies available for studying butterfly migration have changed over time, and document geographic and taxonomic foci in the study of butterfly migration. Method We review publications on butterfly migration published in six languages [English, Simplified Chinese, Traditional Chinese, Japanese, Korean, and Spanish], summarise how migration in butterflies has been studied, explore geographic and taxonomic patterns in the knowledge base, and outline key future research directions. Results Using English search keywords, we found only 58 studies from Asia; however, after searching in local languages, we found an additional 99 relevant studies from China, Japan, and Taiwan. Overall, butterfly migration studies are mostly concentrated in North America and Europe, with only 4.6% from Africa. Most studies focus on three species: monarch [Danaus plexippus], painted lady [Vanessa cardui] and red admiral [Vanessa atalanta]. About 62% of publications are focused on the monarch, with nearly 50% of migratory butterflies mentioned in no more than a single paper. Conclusions Several research methods have been applied to ascribe migratory status and to study the physiology, neurobiology, and ecology of migration; however, virtually all this research is focused on a handful of species. There remain hundreds of species for which we do not understand the full seasonal pattern of movement, flight destinations, wintering, or breeding grounds. A full understanding of movement ecology and migratory connectivity is needed to effectively conserve migratory butterflies.