Where diet, vegetation, and climate overlap: Guiding Vipera ursinii ursinii conservation through a converging approach

The meadow viper (Vipera ursinii ursinii) is a high-altitude specialist whose last systematic dietary analysis in Italy dates back more than 20 years. Here, we present an update in which an ensemble of field-collected data, remote sensing analyses, and modelling/post-modelling procedures converge into a unique, updated assessment to support conservation-aimed spatial planning, under current and future scenarios, for V. u. ursinii in its Central Apennines range. We analyzed field-collected fecal samples to determine dietary composition, checking the species' known specialization on Orthoptera. Based on this, we developed ecological niche models for all orthopteran species occurring at high elevations in the Central Apennines, further synthesizing those into a composite “typical Orthoptera” spatial data, using a biogeographic-based weighting approach. After confirming the high Orthoptera preference of V. u. ursinii, with some prey items identified for the first time in Italy at the genus or species level, we present distribution models for 51 orthopteran species. The resulting current and future (SSPs 3–7.0 and 5–8.5) prey distribution models were integrated into an existing distribution model of V. u. ursinii, refining its estimated environmental suitability by accounting for prey availability. Finally, we coupled these outputs with a map of June-to-September NDVI, averaged across 1999–2020, producing a zonation framework at the scale of each Central Apennines massif. We identified several suitable massifs, though some show suboptimal NDVI values. Gran Sasso consistently emerged as the stronghold under all scenarios, while SSP 5–8.5 projections highlighted declines in several massifs, underscoring the need for fine-scale conservation planning.