Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification
<p>Abstract</p> <p>Background</p> <p>In the permanent daylight conditions north of the Arctic circle, there is a unique opportunity for bumblebee foragers to maximise intake, and therefore colony growth, by remaining active during the entire available 24-h period. We te...
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| Format: | Article |
| Language: | English |
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BMC
2010-06-01
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| Series: | BMC Biology |
| Online Access: | http://www.biomedcentral.com/1741-7007/8/93 |
| _version_ | 1811259919498739712 |
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| author | Chittka Lars Stelzer Ralph J |
| author_facet | Chittka Lars Stelzer Ralph J |
| author_sort | Chittka Lars |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>In the permanent daylight conditions north of the Arctic circle, there is a unique opportunity for bumblebee foragers to maximise intake, and therefore colony growth, by remaining active during the entire available 24-h period. We tested the foraging rhythms of bumblebee (<it>Bombus terrestris </it>and <it>B. pascuorum</it>) colonies in northern Finland during the summer, when the sun stays above the horizon for weeks. We used fully automatic radio-frequency identification to monitor the foraging activity of more than 1,000 workers and analysed their circadian foraging rhythms.</p> <p>Results</p> <p>Foragers did not use the available 24-h foraging period but exhibited robust diurnal rhythms instead. A mean of 95.2% of the tested <it>B. terrestris </it>workers showed robust diurnal rhythms with a mean period of 23.8 h. Foraging activity took place mainly between 08:00 and 23:00, with only low or almost no activity during the rest of the day. Activity levels increased steadily during the morning, reached a maximum around midday and decreased again during late afternoon and early evening. Foraging patterns of native <it>B. pascuorum </it>followed the same temporal organisation, with the foraging activity being restricted to the period between 06:00 and 22:00.</p> <p>Conclusions</p> <p>The results of the present study indicate that the circadian clock of the foragers must have been entrained by some external cue, the most prominent being daily cycles in light intensity and temperature. Daily fluctuations in the spectral composition of light, especially in the UV range, could also be responsible for synchronising the circadian clock of the foragers under continuous daylight conditions.</p> |
| first_indexed | 2024-04-12T18:38:50Z |
| format | Article |
| id | doaj.art-a125182e96854331a80a80c483400dc1 |
| institution | Directory Open Access Journal |
| issn | 1741-7007 |
| language | English |
| last_indexed | 2024-04-12T18:38:50Z |
| publishDate | 2010-06-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Biology |
| spelling | doaj.art-a125182e96854331a80a80c483400dc12022-12-22T03:20:51ZengBMCBMC Biology1741-70072010-06-01819310.1186/1741-7007-8-93Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identificationChittka LarsStelzer Ralph J<p>Abstract</p> <p>Background</p> <p>In the permanent daylight conditions north of the Arctic circle, there is a unique opportunity for bumblebee foragers to maximise intake, and therefore colony growth, by remaining active during the entire available 24-h period. We tested the foraging rhythms of bumblebee (<it>Bombus terrestris </it>and <it>B. pascuorum</it>) colonies in northern Finland during the summer, when the sun stays above the horizon for weeks. We used fully automatic radio-frequency identification to monitor the foraging activity of more than 1,000 workers and analysed their circadian foraging rhythms.</p> <p>Results</p> <p>Foragers did not use the available 24-h foraging period but exhibited robust diurnal rhythms instead. A mean of 95.2% of the tested <it>B. terrestris </it>workers showed robust diurnal rhythms with a mean period of 23.8 h. Foraging activity took place mainly between 08:00 and 23:00, with only low or almost no activity during the rest of the day. Activity levels increased steadily during the morning, reached a maximum around midday and decreased again during late afternoon and early evening. Foraging patterns of native <it>B. pascuorum </it>followed the same temporal organisation, with the foraging activity being restricted to the period between 06:00 and 22:00.</p> <p>Conclusions</p> <p>The results of the present study indicate that the circadian clock of the foragers must have been entrained by some external cue, the most prominent being daily cycles in light intensity and temperature. Daily fluctuations in the spectral composition of light, especially in the UV range, could also be responsible for synchronising the circadian clock of the foragers under continuous daylight conditions.</p>http://www.biomedcentral.com/1741-7007/8/93 |
| spellingShingle | Chittka Lars Stelzer Ralph J Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification BMC Biology |
| title | Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification |
| title_full | Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification |
| title_fullStr | Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification |
| title_full_unstemmed | Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification |
| title_short | Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification |
| title_sort | bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification |
| url | http://www.biomedcentral.com/1741-7007/8/93 |
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