Anthropogenic modification shifts pollinator phenology in the eastern USA.

Understanding the effects of increasing anthropogenic changes on ecological communities is integral to predicting and mitigating such changes in the future. Insect pollinators are vital to ecosystem health. Quantifying pollinator phenology (i.e. flight period) offers insight into human impacts on ecosystem function, yet research is often constrained to narrow geographic and taxonomic scales. To address these constraints, we conducted a large-scale assessment of pollinator phenology across an anthropogenic modification gradient in the eastern USA using citizen science data from iNaturalist. We integrated 83 012 pollinator observations of 52 species with a remotely sensed layer of human modification to quantify species-specific differences in phenological change. We tested whether anthropogenic modification was a predictor of phenology. Our results reveal both taxonomic and spatial variation across a gradient of anthropogenic modification, with 19 species from three orders experiencing phenological shifts. We found evidence that pollinators in more anthropogenically modified areas of the eastern USA have seasons that start and end later in the year. By leveraging citizen science data, this study expands phenological research and provides a broader assessment across taxonomic and spatial scales.