For several minutes in August 2017, a solar eclipse threw areas along a horizontal strip of North America into darkness. Now, researchers report that bees responded to this midday blackout by falling silent. The results, obtained by analyzing recordings from dozens of tiny microphones placed along the eclipse’s route, were published yesterday (October 10) in Annals of the Entomological Society of America.
“We anticipated, based on the smattering of reports in the literature, that bee activity would drop as light dimmed during the eclipse and would reach a minimum at totality,” study coauthor Candace Galen of the University of Missouri says in a statement. “But, we had not expected that the change would be so abrupt. . . . It was like ‘lights out’ at summer camp! That surprised us.”
The project was made possible through a collaborative effort of more than 400 scientists, members of the public, teachers, and students in Oregon, Idaho, and Missouri. Participants hung microphones near bee-pollinated flowers around 16 monitoring stations in the path of the eclipse and sent the devices to Galen and her colleagues.
The level of buzzing in the recordings revealed that while bees were partially active during the phases before and after total eclipse, activity essentially dropped to zero during totality, with just a single buzz recorded during that period anywhere in the country.
The researchers can’t distinguish which species are which from the recorded buzzes—though observations at the monitoring stations suggest that the insects are mostly honeybees or bumblebees. Still, the results offer insight into how bees in general respond to unexpected environmental conditions.
“The eclipse gave us an opportunity to ask whether the novel environmental context—mid-day, open skies—would alter the bees’ behavioral response to dim light and darkness,” Galen says in the statement. “As we found, complete darkness elicits the same behavior in bees, regardless of timing or context. And that’s new information about bee cognition.”
Correction (October 12): The original version of this article incorrectly described the cosmic event as a lunar eclipse. It was, of course, a solar eclipse. The Scientist regrets the error.