Activity patterns of insectivorous bats and birds in northern Scandinavia (69° N), during continuous midsummer daylight ...

• Main Authors: Speakman, J. R., Rydell, J., Webb, P. I., Hayes, J. P., Hays, G. C., Hulbert, I. a. R., McDevitt, R. M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Zenodo 2000
• Subjects: Biodiversity; Mammalia; Chiroptera; Chordata; Animalia; bats; bat; Northern Norway
• Online Access: https://dx.doi.org/10.5281/zenodo.13537788; https://zenodo.org/doi/10.5281/zenodo.13537788

(Uploaded by Plazi for the Bat Literature Project) Previous studies suggest that many species of insectivorous bats are nocturnal, despite the relatively low availability of their insect prey at night, because of the risk of predation by diurnal predatory birds. We hypothesised that if this was the case bats living above the arctic circle would alter their feeding behaviour during midsummer because there would no longer be any benefit to restricting their activity to the period when their prey are least abundant. Alternatively, if bats were more influenced by competition from aerial insectivorous birds they would continue to feed at 'night' to avoid such competition. In northern Norway (69° N), during continuous midsummer daylight, insectivorous sand martins (Riparia riparia) concentrated their aerial feeding activity when aerial insects were most abundant. The birds stopped feeding between 23:00 and 07:00 when aerial insects were least abundant. In contrast, northern bats (Eptesicus nilssonii), fed mostly ...