Butterflies of tropical Asia

Climate change impacts are likely to have major impacts on tropical biodiversity. At the same time, serious insect declines have been documented globally. Two major challenges have created obstacles for our understanding of these two threats to our ecosystems; 1) we lack data on tropical insects, and 2) we lack mechanistic frameworks for understanding climate change impacts on tropical species. Thanks to an Excellent Young Scientists Fund (Hong Kong and Macau) award from the National Natural Science Foundation of China we have been working to address these gaps.

Working with a large international team of collaborators we’ve compiled a database of occurrence records for the butterflies of tropical Asia. We’ve documented over 700,000 records for 3,591 species of butterfly. Using these records, we then built species distribution models to predict hotspots of butterfly and insect biodiversity in the region. We also conducted fieldwork on moths and butterflies in Hong Kong as a means to quantify thermoregulatory responses of Lepidoptera to climatic variation. Our results from this fieldwork highlighted the ability of butterflies to avoid the warmest parts of the day through thermoregulation. Interestingly, most moths appear to have little thermoregulatory ability but may not need much as they are most active during the cooler parts of the night. Finally, we combined these two approaches to mechanistically analyze trends in butterfly communities over time in Hong Kong through the calculation of community temperature indices (which measures the ‘species temperature’ by taking the average temperatures from the occurrence records collected). Altogether, this project advances our understanding of insect and biodiversity declines in the tropics (and tropical Asia specifically) and provides a wealth of promising avenues (and data) for future research.

We are also studying the dynamics of danaid butterfly migration and ecology. Danaid butterflies (subfamily Danainae) are a common winter sight in Hong Kong. In some locations, aggregations of thousands of danaid butterflies can be seen as individuals migrate and/or overwinter in the area. However, very little is known about where these species are going and why. Our on-going research aims to reveal the mystery behind these spectacular butterfly movements so that we can ensure the persistence of future generations of butterflies… and that future generations of people can enjoy these marvels. For more info see our project website on Danaid Butterfly Research in Hong Kong.