Collaborative Research: Assessing Wild Bee Resilience to Heat Waves across Scales of Biological Organization

Wild bees are a critically important insect group responsible for pollinating over 30% of the world’s crops and most wild plants. However, the pollination services bees provide are threatened by extreme weather events — most dramatically, by heat waves. Despite the threats heat waves pose, previous research has been limited to controlled laboratory studies on a handful of bee species. This limited context precludes mechanisms that could buffer pollination services against heat waves in natural settings. Understanding such mechanisms could help guide strategies for supporting the integrity of natural systems and improving food security. Our project bridges the study of individuals, populations and communities and leverages cutting-edge technology to better understand organism responses to the environment. First, the project measures behavior, reproduction and survival of individual bees across life stages, in response to simulated heat waves. Second, the project tracks nesting bees in the wild using automated remote cameras to determine whether bees within a population choose cooler nest locations under heat wave conditions. Third, the project uses AI-assisted camera traps to measure the activity of whole native bee communities before, during, and after naturally occurring heat waves. Spanning detailed study of individual bees to observations of multiple bee species over hundreds of square kilometers, can reveal the scale at which resilience emerges and buffers bees to extreme temperatures. This project also will develop newly-available technologies with promise to make environmental monitoring vastly more efficient and engage public audiences through museum educational program at the University of Minnesota. Wild bees facilitate the pollination of both wild plant populations and agricultural crops, but the ecosystem services they provide are threatened by extreme weather events, particularly naturally occurring heat waves. Despite the potential impacts heat waves pose to plant reproduction via pollinator activity our understanding of their impact on pollinators is limited to controlled laboratory studies, impeding our capacity to determine whether natural resilience mechanisms manifest at increasing scales of biological organization. To address this gap, this research will bridge the individual, population, and community scales to determine how short-term heat events (heat waves) impact native bees across different life history stages. First, we will use experimentally simulated heat waves on a model bee species, Osmia lignaria, to measure behavior and survival across life stages. Second, we will track marked adult O. lignaria at field sites in central California to measure how heat waves impact behavior, survival, and reproduction in the wild. Third, we will use AI-assisted camera traps to measure the activity of all native bee species before, during, and after naturally occurring heat waves. By bridging from single-species greenhouse experiments to observations of multiple native bee species over hundreds of square kilometers, this research will reveal at what scale(s) resilience mechanisms emerge to buffer bee populations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.