Temperature and Precipitation Niche Dynamics Shape Avian Elevational Shift Strategies in the Hengduan Mountains

作者：Shangmingyu Zhang, Yiwei Cao, Yibo Wang, Jiayu Zhang, Jianghong Ran, Muyang Lu, Yongjie Wu · 发表于：Journal of Biogeography · 年份：2026 · DOI：10.1111/jbi.70148 · 被引用次数：1 · 研究领域：Species Distribution and Climate Change、Avian ecology and behavior、Remote Sensing in Agriculture

ABSTRACT Aim Intensifying climatic seasonality drives spatial reorganisation in mountains, but the niche processes underlying seasonal elevational shifts remain insufficiently understood. We test how seasonal changes in climate niche position (optima) and niche breadth (the range of climatic conditions that a species experiences over space and time) along temperature and precipitation gradients predict the direction and distance of bird elevational shifts. Location Hengduan Mountains, southwest China. Taxon Breeding birds. Methods We analysed 42,458 records of 206 species from field surveys and citizen‐science data. We quantified elevational shift direction and distance using the signed and absolute differences between seasonal median elevations. Using fine‐resolution climatic data, we estimated key climatic niche metrics—seasonal optima, annual breadth, seasonal breadth change, and overlap—and evaluated their power to predict shift direction and distance alongside functional traits using phylogenetic Bayesian models. Results We identified three post‐breeding elevational strategies: upslope, downslope, and resident. Although moving in opposite directions, upslope and downslope shifters exhibited congruent seasonal directions of climatic niche change. Bayesian analyses revealed that shift direction in downslope species was associated with seasonal changes in both climatic optima and niche breadth, whereas for upslope species, it was linked primarily to seasonal niche breadth c...