I went to Zoo Zürich a while ago, the pictures in this entry were all shot inside the Masoala Halle.
An employee of the zoo even explained to me all the details of and flaws of this ecosystem.
Simply said, there is not enough sun, especially in the winter. This leads to a lack of flowers.
Which leads to a lack of insects. Therefore, the fauna still needs external nutrition.
But I'm sure it is much more complicated.
I think it's interesting to see that we are still unable to create a self-sustaining system.
Zoo Zürich