Community science data provides evidence for upward elevational range shifts by Eastern Himalayan birds

The ongoing climate crisis is a significant threat to global biodiversity. As Earth warms, many species respond by shifting their geographical ranges either polewards, or in mountainous regions, upslope towards higher elevations, presumably to track suitable thermal environments. Upslope range shifts are of particular concern in tropical mountain ranges because: (a) tropical species are particularly thermally sensitive, (b) species moving upwards could become locally extirpated as they run out of habitable space, and (c) tropical mountains harbor a high fraction of Earth’s terrestrial biodiversity. Rapid upslope shifts can therefore result in significant biodiversity losses. We used community science data over a 13-year period to evaluate whether 93 Eastern Himalayan bird species might be shifting to higher elevations. To do this, we analyzed changes in their occurrence probabilities in eBird checklists from birdwatching hotspots at fixed elevations. We found patterns consistent with up...