This video is about a great reed warbler singing.
Translated from BirdLife in the Netherlands:
Jan 5, 2016 – Great reed warblers have it rough in the Netherlands. Something must be done quickly for this ancient Dutch rattle cane not to become extinct in our country. Therefore BirdLife in the Netherlands has launched a rescue plan. In the Loosdrecht Lakes, the main stronghold of the great reed warbler, the habitat will be improved dramatically.
Of the thousands of breeding pairs of the great reed warbler that once populated our reed marshes hardly more than about 100 are left.