Intensive monitoring of the butterflies of the UNESCO MAB reserve of Monte Peglia (Central Italy) reveals strong potential for local extinctions in a Mediterranean area

Abstract

The impact of human activities is resulting in increased losses of biodiversity on a local and global scale. Detecting local extinctions requires historical data and intensive field surveys, so as to ascertain the actual absence of a species. In this study, we fortnightly sampled 90 plots within the Monte Peglia UNESCO MAB Reserve (~60 km2) from April to October 2022. We also collected all available records for the Reserve in literature and iNaturalist. After our sampling, the Reserve appears in the 4% of the richest cells with similar size and altitude in central Italy. By applying the Potential-Extinction-upon-Time-Series (PETS) algorithm we evaluated the possibility for faunistic erosion in time. Twelve species that were recorded before 2010 but not confirmed in our field surveys produce a moderate PETS value of 21.3%. Based on literature and iNaturalist data, we also identified rare species as those occurring within a 50 km radius of the Reserve in the lowest quartile of occurrences. Approximately half of the unconfirmed species belonged to regionally rare taxa, while others belonged to taxa generally found at higher altitudes in the last decades. Monte Peglia Reserve qualifies as a perfect model for documenting possible local extinctions of butterflies in Mediterranean areas in the near future.