'First Known Photographs of Living Specimens': the power of iNaturalist for recording rare tropical butterflies

Insects are the most biodiverse multicellular organisms, with most of this diversity in the tropics. Butterflies follow the same pattern, with similar to 90% of species from the tropics. Anthropogenic stressors such as habitat loss and pollution are driving butterfly declines globally, with many rare tropical species likely extinct before discovery. Citizen science is a powerful tool for supplementing professional monitoring of tropical butterfly biodiversity and better understanding butterfly biogeography, especially in remote regions or on private land. We created a 'project' on the online biodiversity citizen science platform iNaturalist to collect the first known photographs of rare taxa. Almost 20% of the project's records are butterflies, with observations of 406 butterflies for which the uploaded images are the first known photographs of living specimens. Over 90% of these are from the tropics, with Indonesia, Brazil and Peru the most-represented countries, and Theclinae, Riodininae and Satyrinae the most observed subfamilies. The project's success has been driven by a strong synergistic community of experts and amateur naturalists from around the globe that facilitates real-time discussions and the identification of rare and undescribed taxa. Implications for insect conservation Our project highlights the power of iNaturalist for documenting the occurrence of rare tropical butterflies in typically poorly monitored regions such as Papua and remote areas of South America. These data points provide the stepping stones for a better understanding of tropical butterfly biogeography, and have the potential to inform conservation and management of poorly known species.

Automated summary

Insects, especially butterflies, show the highest biodiversity in tropical regions. However, anthropogenic stressors have led to global declines in butterfly populations, with many rare tropical species possibly extinct before being discovered. Citizen science plays a crucial role in supplementing professional monitoring efforts and improving understanding of butterfly biogeography.