Mismatches in the occurrence of endangered butterflies and macro‐moths inside and outside nature reserves

Globally, nature reserves and protected areas (PAs) have been designed to conserve valuable ecosystems and wildlife against human‐induced threats. However, to which degree PAs save biodiversity is a matter of intense discussion, mainly based on vertebrate data; extensive assessments for invertebrates are largely lacking. We analysed whether butterfly and macro‐moth (Lepidoptera) diversities and abundances increased in PAs in comparison to the initial state and the surrounding landscape during the last decades. We used long‐term records (1900–2022) of Lepidoptera (butterflies and macro‐moths) in the federal state of Salzburg (northern Austria) and recent Austrian Red List endangerment assignments. Irrespective of elevation, records of rare and endangered species increased inside PAs by about 6%. However, only a few species were responsible for this increase in the number of records while the majority decreased within PAs. The total richness of rare and endangered species inside PAs was constantly lower than outside PAs, even after accounting for unequal sample sizes. Still, the majority of rare and endangered species occurs outside PAs while PAs increasingly harbour non‐threatened species. These results demonstrate a mismatch in the spatial distribution of threatened butterflies and macro‐moths and the localisation of PAs in northern Austria. This mismatch causes an insufficient protection of the insect diversity despite the fact that 20.4% of the study area is strictly protected. We call for a more diversity‐focused designation of PAs that also considers the positive contribution of heterogeneous landscapes.