Black Storks are a rare sighting in the Netherlands.
Two juveniles were present for a few days in Wieringermeer in September 2014 (1st & 2nd photo).

1st & 2nd photo: Wieringermeer, The Netherlands, 13 September 2014
3rd, 4th & 5th photo: One juvenile in the company of a White Stork. Blikkenburg, Zeist, The Netherlands, 19 August 2021