Bees Go Eerily Silent During Total Solar Eclipses

On August 21, 2017, an estimated 215 million people across America watched a total solar eclipse, either in-person or online. But humans weren’t the only animals that dropped what they were doing to experience the eerie moments of totality, when the Moon fully obscures the Sun.

A study published Wednesday in The Annals of the Entomological Society of America shows that bees at several locations in the US became suddenly quiet and still as the Moon’s shadow swept over them.

"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," lead author Candace Galen, professor of biological sciences at the University of Missouri, said in a statement. "But, we had not expected that the change would be so abrupt, that bees would continue flying up until totality and only then stop, completely. It was like 'lights out' at summer camp! That surprised us."

Galen and her colleagues invited over 400 people—including elementary students—to participate in their experiment. Volunteers were instructed to set up USB microphones near bee-pollinated flowers at 16 locations in Oregon, Idaho, and Missouri that fell within the eclipse’s path of totality. Most of the surveilled insects were bumble bees and honey bees.

Galen’s team then collected and listened to all the recordings, which captured only one lone bee buzzing during the moments of totality. The researchers also discovered that the bees slowed down immediately before and after the eclipse, perhaps because they mistook the partial dimming of the Sun for dusk and decided to return to their nests for the night, even though it was the middle of the day.

"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 said. “As we found, complete darkness elicits the same behavior in bees, regardless of timing or context. And that's new information about bee cognition.”

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