Climate change and heavy-metal pollution are quieting bees’ distinctive buzz, which may soon become rare as warming lowers the frequency and pitch of their wing vibrations.
Abnormally high temperatures and air pollution from heavy metals are weakening bees’ buzzing. That threatens their communication, plant pollination, and the functioning of Earth’s ecosystems.
What Did the Researchers Report?
A team at Uppsala University in Sweden studied yellow-faced bumblebees, one of Europe’s most common bumblebee species. Using accelerometers, they measured the frequency and pitch of the bees’ buzzing, focusing on the sounds the insects make when they’re not flying.
Their analysis found that high temperatures and heavy-metal exposure make the bees’ muscles less effective at contracting during buzzing. That leads to weaker wing vibrations and lower sound volume, the Daily Mail reported.
“People have long been fascinated by insect flight muscles, which power some of nature’s most efficient flight systems. But few realize that bees use those muscles for other functions beyond flight,” said Dr. Charlie Woodrow, a co-author of the study.
He explained that those muscle vibrations are necessary for communication, defense, and for buzz pollination of certain plants.
Buzz pollination is a behavior in which a bee on a pollen-laden flower contracts its flight muscles up to 400 times per second. These rapid vibrations shake the pollen loose.
Many common garden plants, such as tomatoes, blueberries, and honeysuckle, rely on this type of pollination.
“Now we know that certain environmental pollutants can affect bee buzzing, making it a potential indicator of ecosystem health,” Dr. Woodrow said. He added that if these vibrations vanish, colonies could suffer poor communication, impaired thermoregulation, and reduced reproductive success.
These pollination problems could have serious consequences for plant biodiversity.
If global warming continues, bees may increasingly avoid flowers that require buzz pollination, Dr. Woodrow said.
The research team’s findings were presented at the annual conference of the Society for Experimental Biology in Antwerp, Belgium.
