I have seen identical aviaries several time. I guess it was "fashion" zoo trend few decades ago. Zlin-Lesna still has such old aviary for keas.
Also Jihlava zoo has similarly designed big round aviary for eagles, but from triangles and not from 6-cornered fields. It was built around year 1960. Inspiration was an advertisement photo received from Italian animal trader, who also was selling equipment.
It's called a geodesic dome. They were very fashionable across various forms of construction - from houses to stadia - in the 1950s to 1970s. They are efficient to build because spheres are the shapes that contain the greatest volume for the least surface area. Obviously, though, this is only a partial sphere.
