By Stephen Beech via SWNS
Bees are being kept awake by artificial light – just like humans, reveals new research.
However, the issue has serious implications as disruption to pollinators’ body clocks harms “vital” ecosystems, according to American scientists.
Researchers at the University of California, San Diego, have found that light disruption is not only a health concern for humans.
The new study, published in the journal Scientific Reports, found that artificial light disrupts the circadian rhythms of honey bees and poses a threat to their “essential” role as pollinators.
Doctoral candidate Ashley Kim, who led the study with Professor James Nieh, said: “Our research shows just how sensitive honey bees are to changes in their environment, particularly to something as seemingly benign as artificial light.
“By disrupting their circadian rhythms, we see clear evidence of reduced sleep periods.
“This raises significant concerns, not only for bee health but also for the health of ecosystems that depend on them for pollination.”
She explained that honey bees play a “crucial” role as pollinators of wild plants and vital crops, providing services that support ecosystem stability and global food security.
Without pollination, crops worth tens of millions of pounds would be at risk.
Honey bees usually prefer to nest in dark environments, although a small amount of light can enter from the hive entrance.
Sleeping bees typically remain immobile, but show subtle movements if disturbed by nestmates.
But bees sleep outside when they swarm or when they form “bee beards” outside the nest on hot evenings, which are increasing as a result of climate change.
While the prevalence of artificial light at night (ALAN) – or light pollution – on sleeping honey bees varies from region to region, modern urban environments are increasingly exposed to artificial light conditions, especially as temperatures rise.
Because there has been a resurgence in urban beekeeping to support bees and their critical pollination services, the research team say bees that experience hotter weather are now potentially more exposed to ALAN.
Scientists say, just like humans, when bees experience a poor night’s sleep and disrupted circadian patterns, problems emerge.
The research team explained that sleep is “crucial” for the health and fitness of honey bee colonies since they depend on an intricate system of communication known as the “waggle dance” that informs hive mates about the location of food sources.
Bees don’t dance as well and therefore do not communicate as well if they do not get enough sleep, according to the study.
Through a series of experiments spanning several years, the research team compared groups of bees that underwent normal sleep in the dark with others that were subjected to continuous artificial light.
The results clearly showed that prolonged exposure to light “significantly disrupted” the circadian rhythms of honey bees, leading to impaired behavior.
As the bees were video recorded 24 hours a day during the experiments, Ms Kim could immediately see the effects of disrupted sleep.
She said: “Even without analyzing the data you can tell that there was something going on.
“The bees that were under constant light slept less.
“The effects of light pollution on biological systems is fairly unknown and something people normally don’t think about, which is why it’s a rapidly evolving field.”
The research showed that bees exposed to continuous light slept less and were more frequently disturbed by other bees compared to those kept in normal darkness.
Bees under continuous light also showed a preference for darker areas within their experimental cages.
Nieh said: “Understanding the factors that affect bee health, such as light pollution, is essential for developing strategies to protect pollinator populations.”
He added: “Light pollution is a growing issue, with artificial light now covering a quarter of the Earth’s surface, and this research sheds new light on how such disturbances may be harming pollinators.”
