This appears to be a brilliant enclosure for maned wolves, but of course the animals are notoriously difficult to spot in lush zoo exhibits and I'm guessing that that is the case in Rotterdam. It reminds me a bit of the Oklahoma City Zoo's maned wolf exhibit, which is almost as equally lush and green.
Yes, they can be quite difficult to spot. If you enlarge the photo you should be able to just see the maned wolf below some of the yellow leaves in the background...
