Background: A solar eclipse is an occasional natural phenomenon that can alter the physical and biological processes of organisms. On 21 June 2020 a unique opportunity was offered to evaluate how birds change their behaviour during an eclipse. Bird behaviour was categorised using a scan-sampling technique before, during and after the solar eclipse, and at a different time of eclipse day.
Results: Before the eclipse major activity categories were moving (52.45%), foraging (40.20%), and courtship (2.94%) respectively, but there were no roosting/resting observations at this time. These behaviours were much reduced during the eclipse, while roosting accounted for 14.6% of behaviour. When the eclipse began at 06:50, their calling and flying increased, and singing decreased. At maximum eclipse (07:20h), there was a profound decrease in calling, singing, foraging and moving, and courtship; while washing and floating were not observed. After the eclipse, most time was spent foraging (36.3%), followed by moving (flying), with roosting reduced to 2.4%.
Conclusions: Clear and radical behavioural changes were observed when the eclipse was started and maximum. Responses of birds to the environmental factor changes associated with the solar eclipse might be the root cause of observed unusual behavioural change.