You can hear them in the night at the west coast cliffs of the Canaric Island La Palma. They are very shy and I had to climb a cliff of 60 meters height in the night to get them very close to my SONY-PCM-D50 recorder. Yellow Beaked Shearwaters are migrating birds living on the sea and flying thousends of kilometers over the sea each year to come to their breeting sites on the cliffs of the the Canaric Island La Palma. In order to protect their breed from predators they fly every night when it is dark into the cliffs to feed their breed and the shouts are made in order to navigate on the cliffs and on each other.