Photo apps data of Austrian butterflies

The currently observed declines in insect diversity and abundance, and the resulting changes in species composition have highlighted the need to establish a standardized and comprehensive biodiversity monitoring system across Europe and the world. However, respective standardized collections and time series to trace these changes are still largely lacking. Extensive observation data on plants and animals are currently compiled through the development and use of various photo apps. Here, we provide faunistic data on butterflies from Austria to compare the completeness and spatial distribution of butterfly records stored in the Global Biodiversity Information Facility with three popular photo app-based initiatives for nature monitoring, Blühendes Österreich, iNaturalist, and observation.org. Observed species richness and the spatial distribution of records across Austrian Federal States strongly varies among the photo apps. Blühendes Österreich depicted the lowest number of species (152 out of record Austrian 216 species) with the highest number of records, while iNaturalist (180) and observation.org (182) returned more species. Apparently, behaviour of the users strongly differed between the photo apps. Our study indicate that the users of a photo app and also GBIF bias the information on biodiversity recording.