Overview
- The study, which was published on June 15 in Nature Communications, tested heat tolerance in more than 95 native bee species collected across mainland Australia.
- Researchers found nest microclimates explain heat tolerance: stem or plant-stem nesters experience the hottest nests and show the highest physiological heat limits, cavity nesters are intermediate, and ground nesters are the least heat tolerant.
- When researchers used nest temperatures rather than coarse air data, vulnerability rankings flipped so that stem-nesting bees became the most at risk because they cannot seek cooler refuges inside their nests.
- The study shows tropical species are closest to their thermal limits, that within-lifetime acclimation offers little short-term buffering, and that evolutionary increases in heat tolerance are possible but likely slow.
- Authors recommend protecting cool microhabitats such as tropical forest patches and cutting emissions to safeguard native pollinators and the crops and livelihoods that rely on them.