They're in a large exhibit to the right of the entrance to the Pachyderm House - not the small rodent tank (currently displaying Brown Cuis), but between that and the African Elephant paddock.
We must have crossed paths at the Tierpark this past week!
@sooty mangabey If you were there on Friday then we missed each other. It is definitely on my "must return" list, even though I did go twice last week.