Bumblebees may have the ability to soar to great heights, a new study suggests.
The findings, published in the Royal Society journal Biology Letters, reveals that the tiny insect has the capacity to fly at elevations greater than Mount Everest. While they would not be able to survive the frigid Himalayan temperatures, researchers determined bumblebees could stay in flight in low-oxygen and low-air-density conditions.
"Much to our surprise, [bees] can fly much higher than we thought they would be able to," Michael Dillon, an ecologist at the University of Wyoming in Laramie, told Smithsonian Magazine.
Researchers came to their conclusion after collecting six alpine bumblebees from western China. They placed the bees in transparent sealed boxes – much like a hyperbaric chamber -- where they altered the oxygen and air-density levels to simulate increasing elevation with a constant temperature.
"Just by pumping air out, we can reduce the total barometric pressure, which would be like carrying the bee up the mountain," Dillon explains.
All of the bees were able to fly under the harsh conditions equivalent to 13,000 feet. Two bees flew higher than 29,527 simulated feet — about 500 feet higher than the summit of Mount Everest.
Dillion and his colleagues suspect the bees were able to remain in the air by moving their wings at a bigger angle, the Australian Broadcast Corporation reports.
"They're not increasing how quickly they beat their wings, they are just beating their wings through a much bigger arc," Dillon said. "So they can push more air down per amount of time and that allows them to fly at these really high altitudes."
But flying at such heights poses a host of challenges for bumblebees.
"If you have fewer molecules around, it's harder to push enough molecules down per unit time to offset your body weight, which is essentially what you're doing when you're flying," Dillion says explaining the reduced air density makes it harder for bees to get altitude. Another factor is less oxygen – a flying bumblebee needs 15 to 20 times more oxygen than an athlete. How bumblebees can survive in low-oxygen conditions still eludes scientists.
"It's remarkable that they can do it, but we're not sure how yet," Dillion said.
The findings come at a time when climate change is forcing animals to higher elevations in search of colder conditions – a challenge alpine bumblebees may soon face. The results may also lead to aeronautical developments to transport heavy loads in higher elevations, like helicopters that struggle to perform rescues on Mount Everest.
Researchers say the next step is to study bumblebees that live in lower elevations to see if they are capable of surviving at higher altitudes – or whether this trait is found only in alpine bumblebees.