We've updated our Privacy Policy to make it clearer how we use your personal data. We use cookies to provide you with a better experience. You can read our Cookie Policy here.

Advertisement

Artificial Light Disrupts Honey Bees Sleep

Honey bees in a hive.
Credit: PollyDot/ Pixabay
Listen with
Speechify
0:00
Register for free to listen to this article
Thank you. Listen to this article using the player above.

Want to listen to this article for FREE?

Complete the form below to unlock access to ALL audio articles.

Read time: 3 minutes

In an emerging red flag for the digital era, sleep experts have warned us to avoid screen time in bed, sounding the alarm that light emitted from phones and other electronic devices can disrupt our sleep patterns. That’s one way that science is waking up to the broad range of health and disease implications related to circadian biology and our daily sleep-wake cycles.


Now, researchers at the University of California San Diego have found that light disruption is not only a health concern for humans. A new study led by PhD candidate Ashley Kim and Professor James Nieh in the School of Biological Sciences has found that artificial light disrupts the circadian rhythms of honey bees and poses a threat to their essential role as pollinators. 


“Our research shows just how sensitive honey bees are to changes in their environment, particularly to something as seemingly benign as artificial light,” said Kim of the study, published in Scientific Reports. “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.”

Want more breaking news?

Subscribe to Technology Networks’ daily newsletter, delivering breaking science news straight to your inbox every day.

Subscribe for FREE

Honey bees play a crucial role as pollinators of wild plants and important crops, providing services that support ecosystem stability and global food security. Without pollination, crops worth tens of millions of dollars would be at risk.


Honey bees generally prefer to nest in dark environments, although a small amount of light can enter from the hive entrance. Sleeping bees typically remain immobile but exhibit subtle movements if disturbed by nestmates. However, bees sleep outside when they swarm or when they form “bee beards” outside the nest on hot evenings, which are increasing under 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 of urban beekeeping in many areas to support bees and their critical pollination services, bees that experience hotter weather are now potentially more exposed to ALAN.


Like us, when bees experience a poor night’s sleep and disrupted circadian patterns, problems in behavior and function emerge. 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 in the environment. Bees dance more poorly and therefore do not communicate as well if they do not get enough sleep.


Through a series of experiments spanning several years, the UC San Diego researchers 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 behaviors. Since the bees were video recorded 24 hours a day during the experiments, Kim could immediately see the effects of disrupted sleep.


“Even without analyzing the data you can tell that there was something going on… the bees that were under constant light slept less,” said Kim. “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.”


Among the details described in the paper: Bees exposed to continuous light slept less and were more frequently disturbed by their peers compared to those kept in normal darkness. Also, bees under continuous light exhibited a preference for darker areas within their experimental cages.


“Understanding the factors that affect bee health, such as light pollution, is essential for developing strategies to protect pollinator populations,” said Nieh. “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.”


Two coauthors of the study, Aura Velazquez (Universidad La Salle México) and Belen Saavedra (Berea College), are undergraduate students who participated in the research as part of UC San Diego’s ENLACE initiative, a binational summer program in which students conduct research during a seven-week project.


“I am pleased that the ENLACE summer research program was pivotal in providing research experiences for the student authors of this study,” said Olivia Graeve, the director of the ENLACE Program at UC San Diego and a professor in the Department of Mechanical and Aerospace Engineering, Jacobs School of Engineering. “By fostering collaboration between students from Latin America and the United States, we help young researchers gain valuable hands-on experience, building skills and friendships that extend across borders. This project exemplifies the impact of ENLACE, as it brings together diverse perspectives to address global challenges like pollinator health and environmental sustainability.”


Reference: Kim AY, Velazquez A, Saavedra B, Smarr B, Nieh JC. Exposure to constant artificial light alters honey bee sleep rhythms and disrupts sleep. Sci Rep. 2024. doi: 10.1038/s41598-024-73378-9


This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source. Our press release publishing policy can be accessed here.