As the world experiences a Solar Eclipse this weekend, along with the Summer Solstice on June 20, 2020, let’s find out how eclipses affect bees.

Remember the Great American Eclipse of August 21, 2017? Where were you? Hundreds of millions of people watched it, some traveling to specific places along the path hoping for an unparalleled view. Many can tell you exactly where they were.

While millions focused on the total solar eclipse, an even greater event was happening in the path of totality. Bees also stopped their routines. When the moon eclipsed the sun, bees stopped buzzing and went silent during the totality of the solar eclipse. A bee’s buzz is caused when the insect vibrates its wing muscles. If a bee is flying, it is buzzing.

This 1:30-minute video about bees and eclipses is produced by the Australian Academy of Science:



Candace Galen, Ph.D. is a professor of biological sciences at the University of Missouri and was the lead researcher of a unique study about how solar eclipses influence bee behavior. She and her colleagues recently field-tested a bee pollination tracking system that worked remotely by listening for bee flight buzzes in soundscape recordings.  

Researchers from the University of Missouri organized 16 acoustic monitoring stations to monitor bee activity—or lack of it—during the solar eclipse. Over 400 citizen scientists, members of the public and elementary school teachers and students in their classrooms participated along the 2017 path of totality, which curved from Oregon through Idaho and Missouri.

Galen said few formal studies had been done about bee behavior during a solar eclipse, so it was a perfect fit. Most of the bees monitored were honeybees (Apis mellifera) and bumblebees (genus Bombus). Mini USB microphones and temperature sensors were hung on lanyards near bee-pollinated flowers hours ahead of time so volunteers could enjoy the eclipse.

Results, which were published on October 10 in the Annals of the Entomological Society of America, surprised the researchers. Bees continued activities during the partial-eclipse phases before and after totality. They stopped flying completely during the totality phase of the solar eclipse. These results were consistent across the country. They expected activity to drop as the light grew dimmer, with the least activity at totality, but instead the change was abrupt. Bees flew up until totality, then completely stopped in a ‘lights out’ manner.

The devices were sent to Galen’s lab, where the recordings were matched up with the eclipse periods in each location and analyzed for number of and duration of bee flights as well as light and temperature monitoring in certain places.

Foraging bees are known to fly more slowly at dusk and return home to their hives at night, so the solar eclipse triggered the same behavioral response to dim light and darkness. This provides new information about bee cognition concerning complete darkness, regardless of timing or context.

Scientists studied how certain animals responded to the 1991 eclipse over Mexico, Central America and South America. Desert cicadas stopped chirping. Orb-weaving spiders spinning webs deconstructed them during totality, then rebuilt them when the sun returned. During the 1932 total solar eclipse over Canada, Maine, Vermont and New Hampshire, the public observed honeybees return to their hives.

The next North American total solar eclipse date is April 8, 2024. Galen and her team are enhancing their audio-analysis software and hope to explore whether bees go home when the lights go out at eclipse totality in 2024. She thinks many people will help again, since the last total solar eclipse was a big hit and adding the bee research project to it was fun.

Beekeepers, if your bees do anything 'different' during the solar eclipse this weekend and you get some video footage, please share with our readers on our Facebook page.