‘The Scientist’ brings attention to climate change’s impact on pollinator physiology

Animals Are Shape-Shifting in Response to a Warming World

(Thanks to Bruce Taubert for the Centris photo used for this article)

Barrett’s research with Dr. Meredith Johnson on body size declines in male Centris pallida bees over the last forty years was featured in an article on species’ climate adaptations in The Scientist.

This project demonstrated the value of long-term datasets to our understanding of organismal biology - our work relied on male body size data collected by Dr. John Alcock from 1974 to 2013, and Barrett’s data collection in 2018-2022. Together, these data demonstrated that patrolling male bees have shrunk nearly 4% in average head width. Additionally, C. pallida males come in two ‘morphs’ that vary in color, behavior, and body size. The large morph population has shrunk from 21% of all males in 1974 to only 13% of all males by 2022.

Notably, shrinking body sizes may not be a direct result of increased global temperatures in the C. pallida case. Climate change may instead be an indirect cause of C. pallida body size declines: reduced floral resource availability as a result of higher temperatures, increased drought, and potential phenological mismatch (where flowers emerge before the bees because of warming) may drive body size shifts.