They seem to be two parents and their (smaller, less glossy) youngster.
This May 2019 video from Friesland province in the Netherlands is about black-tailed godwits, including mating and hatching of the young birds.
This video says about itself:
Cinereous Vulture – Aegypius monachus – Monniksgier / Schriek – Belgium / 8 May 2019
The bird was born in the wild, of unknown origin, and was rescued from malnutrition in the province of Palencia, in northern Spain. After recovering, it was ceded to the Monachus Project for reintroduction in the province of Burgos. Here the bird has gone through an acclimatization phase in the facilities for 9 months, and was released with 15 other black vultures on October 7, 2018.
Translated from Dutch NOS TV today:
The cinereous vulture, with a wingspan of 2.5 to 3 meters, is the largest bird of prey in Europe; worldwide only the condor is bigger. The species is only found in Europe in mountainous areas such as Spain and Greece. The animal species had not been seen in the Netherlands since 2005. …
There are still around 2000 couples in Europe, which makes the animal rare but not threatened. A reintroduction program is underway in France and Spain.
Remarkably enough, a cinereous vulture travelled through the Netherlands earlier this month, but as far as is known, no one observed it. This bird, called Brínzola and equipped with a transmitter, travelled in a few weeks from the Pyrenees via the south of our country to the south of Norway, a journey of more than 3000 kilometres.
Bird lovers think that this bird species may be seen more often to the north in the coming years, because wandering visitors are exploring now that the population is increasing.
Incidentally, things ended badly for the individual that landed here in 2005 in the Oostvaardersplassen. ‘Carmen‘ flew against a train …; possibly she could not fly well because she was moulting. The animal was stuffed by Naturalis museum.
This is a black woodpecker video.
This 23 May 2019 video shows shelduck ducklings imitating their mother in looking for underwater food.
Gerco Vos made this video in the Bleiswijkse Fles lake in the Netherlands.
This 23 May 2019 video shows a mating marsh harrier couple.
Pieter Torn in the Netherlands made this video.