On Mykines one can hear birds song all year round. The wren can be heard singing even in the middle of the winter. But most sounds from the birds on Mykines may more likely be called voices or screams, for not all are pretty in the ear of man. But all the voices must count as a communications tool, with a presumably high information content.
The sound of storm petrels can be heard continuous for more than half an hour. It might just sounds monotonously, but yet there are nuances and variations. Sometimes one can hear them solo, but at other times in duet or trio, with a very varied course.
Shearwaters can also be heard, both solo and duet, in long sequences.
Scientists have recorded more than 80 different sounds of ravens with specific meanings. So one must assume, that they can inform each other about quite a lot.
Guillemot and its young exchange many sounds and we know, that the young will be engraved on its parents already while the youngster is still in the egg. And when the young leave their nesting place, which at many places is a jump from a great height, many sounds are also exchanged.