2021 ESA Annual Meeting (August 2 - 6)

How to study bees without killing them

On Demand
Elizabeth E. Crone, Tufts University;
Background/Question/Methods

In recent years, there has been an enormous rise in interest in the conservation of wild bees. Ecologists have prioritized documenting patterns of bee diversity and declines, often employing lethal and taxonomically biased methods. These approaches have left glaring holes in our understanding; even for the most common species we rarely know where they nest, their generation times, or how far they disperse. We argue these gaps stem from an ethos of using many species to characterize patterns rather than studying single populations to understand mechanisms. One argument is that many species of bees can only be identified through lethal sampling. Another argument is that a single species study is a sample size of one in relation to broad community patterns. These lines of reasoning contrast with the longstanding tradition of studying single populations of model taxa to test theory through focused observations and experiments. We review three ecological processes—nesting habitat selection, voltinism and phenology, and movement—for which bees could be excellent model systems to advance theory while also filling critical knowledge gaps for conservation.

Results/Conclusions

Wild bee populations could be ideal model systems for studying habitat selection at multiple spatial scales. This area of theory is well developed for long-lived vertebrates such as migratory birds. Studying bees in this framework would extend theory to annual species that typically select habitat only once in their lives. Second, bees would be excellent model systems to test theory related to the timing of life cycle events. For instance, bet-hedging theory is best developed for desert annual plants, but equally applicable to parsivoltine bees. And last, bees could inform theory for how animals move through heterogeneous landscapes since behavioral modes are clearly distinguishable in many bee taxa. These three areas of theoretical research would also fill broad gaps in our knowledge of the basic biology, natural history and demography of wild bees. We also address the concern that lethal sampling is necessary to study bees by suggesting numerous taxa that can be identified on the wing. As part of this talk, we will invite researchers to join us in building a community of scientists who study mechanisms of population dynamics in wild bees, as a step towards building collaboration among research groups in this area.