UK’s furry bumblebees ‘keeling over’ in heatwaves
The effect of heat waves on bumblebees is twofold.
Species in the UK have adapted to our historically cooler climate, with oily, furry bodies that help them retain heat and strong flight muscles that warm them as they fly.
However, while their muscles produce more heat in a heat wave, their thick fur and round bodies make it difficult to cool down.
Foundation’s scientific director Dr. Richard Comont says that when temperatures reach around 28 to 32°C, UK bumblebees may struggle to fly without overheating. If they can’t fly, they can’t find food.
“They actually cook themselves from the inside out,” Comont says. “Once their internal body temperature gets well above 40°C, they literally start to die, they start to roll over.”
BeeWalk data shows population numbers dropped significantly in 2022, when the UK experienced three official summer heatwaves, with temperatures reaching 40.3°C.
Red-tailed, buff-tailed and scalloped bumblebees, three of the country’s most common species, peaked at well below normal levels, with declines of 20%, 25% and 35%, respectively, before falling further in the fall as colonies struggled.
The effects appeared to last beyond that summer. BeeWalk data showed overall queen counts were below average in March, April and May 2023.
