Bird diversity responses to mega-events influence: A case study of the Beijing 2022 Winter Olympics

Mega-events such as the Olympic Games are catalysts for rapid regional transformation, but their ecological impacts remain underexamined, particularly with respect to biodiversity. Based on over 44,000 citizen science records from 2018 to 2024 across Chongli and Yanqing Districts, this study evaluated the impact of the Beijing 2022 Winter Olympic Games on bird diversity. We quantified temporal changes in bird diversity and evaluated the relative influence of environmental factors before and after the Games. Although there was a transient decline during the active preparation and construction phase (2019–2021), the estimated species richness and Simpson diversity eventually increased by 17.66% and 8.95%, respectively, from 2018 to 2024. Post-Olympic gains in bird abundance were significant for water birds, migratory species, omnivores, and herbivores. Generalized linear models demonstrated that habitat factors, particularly vegetation and water coverage, significantly affected bird diversity. Sensitivity analysis further identified the percentage of tall vegetation as the most influential variable in the richness model (main effect: 0.25; total effect: 0.58). These results establish habitat factors as the primary drivers of bird diversity, not only outweighing the negative effects of human disturbance but also exhibiting substantially greater predictive stability than anthropogenic variables. Moreover, bird communities exhibited increased ecological resilience in the post-Olympic period, with reduced sensitivity to environmental factors. These findings underscore the potential for integrating biodiversity conservation into mega-event planning and offer actionable insights for future sustainable urban and regional development strategies.