Generalist ‘Winners’ Replace Specialist ‘Losers’: Interactions Between Regional Anthropogenic Impacts and Climate Warming Drive Long‐Term Wild Bee Declines

ABSTRACT Aim To quantify how interacting regional anthropogenic pressures and climate warming have driven long‐term changes in wild bee community composition and diversity. Location Eight sites within a 300 km 2 region around Linz, Upper Austria (266–616 m a.s.l.). Methods We analysed 11,934 museum and contemporary occurrences (out of a larger dataset of 17,515 records) of 340 wild bee species collected between 1910 and 2021. Temporal presence–absence data (in six 15‐year intervals) were linked to interval‐averaged temperature, precipitation and human population density (proxy for anthropogenic impact) as well as sampling effort (total number of sampling events). We fitted a single binomial generalised linear mixed model (GLMM) with species and site as random effects and species category (Intermittent, Disappearing, Appearing) interacting with environmental predictors. Post hoc trend comparisons and trait‐based analyses further elucidated group‐specific responses. Results Community turnover drove an ~18% decline in species richness over the observation period. Disappearing specialists declined under rising human impact and warming. Intermittent species were favoured by wetter and warmer intervals but negatively affected by higher human densities. Appearing generalists expanded under warming and anthropogenic pressures with no precipitation response. Omnipresent generalists remained consistently present irrespective of environmental variation, underscoring their broad tolerance but contributing to functional homogenisation. Sampling effort improved detection but did not alter these ecological patterns. Main Conclusions Compounded anthropogenic pressures and climate warming drive specialist losses and generalist expansions, while precipitation buffers only intermittent species. Omnipresent generalists sustain baseline pollination, but community shifts toward generalists homogenise functional diversity and undermine ecosystem‐level pollination resilience. Conservation must address multiple drivers—protecting specialist habitats, maintaining connectivity as well as climate‐ and precipitation‐sensitive refugia—to preserve functional diversity and pollination services under ongoing global change.