People who live near the cauldron know very well that males often sing all night. However, this bird does not belong to the list of nocturnal animals, because they eat, live and sing during the day.
Valenti Amrhein of the University of Basel, Switzerland, the lead author of the new study on the bird, said: 'We are curious that why some nightingale birds sing at midnight.'
The team found that when a male cauldron had a female friend, he stopped his song but continued to sing during the day.
Further analysis showed that 'single' males did not move at night, but during the day they moved around - sometimes near the territory of other males - during singing. This shows that daytime singing is to explore territorial limits, while night singing is for another thing.
The last experiment with female nightingale solved this question. The researchers found that while the males had no one-seated pair and sang all night, the females became very active at midnight. They fly from one male to another, listening to 'singers' for a few minutes. They are definitely looking for the most suitable partner at night.
Amrhein said: 'The most interesting thing here is that we have discovered an animal that females seek partners and males looking for territory at different times of the day. This is a phenomenon we have never seen before. '
The findings were published in the journal Proceedings of the Royal Society B.