June 29, 2010
Bees Refuse To Work Nights
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 maximize 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".
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".
Reference: Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification. Ralph J Stelzer and Lars Chittka. BMC Biology (in press)
Image Caption: These bumblebees are tagged with rfid chips. Credit: Stelzer et al., BMC Biology
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