From research to conservation: Site selection for habitat restoration of a narrowly distributed and critically endangered butterfly

An alarming loss of insect diversity is occurring globally, with a substantialportion of European endemic butterflies currently threatened with extinction.Species with narrow distributions are in urgent need of conservation actions.This study focuses on Polyommatus humedasae, a monophagous butterflyendemic to a restricted area in northwestern Italy, where its primary threat iswoody encroachment. We developed a replicable and data-driven workflow toassist in selecting areas for habitat restoration, based on high-resolution spe-cies distribution modeling. Presence data derived from a recent mark-release-recapture study were combined with topographic variables and vegeta-tion indices from remote sensing to generate a fine-scale habitat suitabilitymodel. Based on the habitat suitability map, we assessed connectivity to iden-tify critical areas for species movement. We modeled the probability of pres-ence as a function of vegetation cover, identifying the optimal tree cover forthe species. Restoration areas were prioritized where patches were unsuitabledue to excessively high tree cover and where intervention could enhance con-nectivity. An area of 0.6 hectares was selected for restoration, considering addi-tional criteria such as impacts on other conservation elements, accessibility tothe area, availability of financial resources, and stakeholder involvement. Thisapproach demonstrates the practical applicability of species distributionmodels in guiding ecological restoration and enabled the development of amanagement plan aimed at maintaining landscape heterogeneity through adynamic, small-scale strategy focused on key areas for species movement.