Public Release:  Even the midnight sun won't convince bees to work nights

BioMed Central

IMAGE

IMAGE: These bumblebees are tagged with rfid chips. view more

Credit: Stelzer et al., BMC Biology

Bees observe a strict working day, even in conditions of 24-hour sunlight. Researchers writing in the open access journal BMC Biology tagged worker bumblebees with a radio identifier, similar to an Oyster Card, which was used to monitor their movements during the constant light of the Arctic summer.

Ralph Stelzer and Lars Chittka from Queen Mary University of London, UK, carried out the study at a research station in Northern Finland. According to Stelzer, "Constant daylight would seem to provide a unique opportunity for bumblebee foragers to maximise intake, and therefore colony growth, by remaining active during the entire 24-hour period. We found that bees do not naturally take advantage of this opportunity, suggesting that there is some benefit to an 'overnight' break".

The researchers studied both native bees and a group of bee colonies they imported into the Arctic. Both species worked a day shift, with maximum activity around midday, and retired to their nests well before midnight. Stelzer and Chittka speculate that the bees must have some way of telling the time in the absence of day/night cues, suggesting that the insects may be sensitive to light intensity and quality or changes in temperature.

Speaking about the possible advantages gained by taking some time off, the researchers said, "Despite the light, temperatures do fall during the Arctic 'night', so it may be that the bees need to return to their nests in order to warm their brood. Also, it has been suggested that a period of sleep helps bees to remember information gained during the day's foraging".

###

Notes to Editors

1. Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification
Ralph J Stelzer and Lars Chittka
BMC Biology (in press)

During embargo, article available here: http://www.biomedcentral.com/imedia/1029621975385769_article.pdf?random=514510

After the embargo, article available at the journal website: http://www.biomedcentral.com/bmcbiol/

Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.

Article citation and URL available on request at press@biomedcentral.com on the day of publication.

2. Pictures of radio-tagged bees are available here:
http://www.biomedcentral.com/graphics/email/images/bumblebee_rfid.jpg
http://www.biomedcentral.com/graphics/email/images/bumblebee_rfid_2.jpg

More pictures are available on request.

3. BMC Biology is the flagship biology journal of the BMC series, now incorporating Journal of Biology, the premier biology journal of BioMed Central, and publishes peer-reviewed research and methodology articles of special importance and broad interest in any area of biology and biomedical sciences, as well as full reviews, opinion pieces, commentary and Q&As on topics of special or topical interest. BMC Biology (ISSN 1741-7007) is covered by PubMed, MEDLINE, BIOSIS, CAS, EMBASE, Scopus, Zoological Record, CABI, Thomson Reuters (ISI) and Google Scholar.

4. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.