Yes, they are. I was there with zg - it was just starting to get dark so both species were active but photos difficult. Was quite happy with the attached shot though.
I didn't say there was anything wrong with it. I suppose there is some logic in that they are both species which have been introduced into Europe and their ranges now overlap.
You can probably see wild moose and rhea in New Zealand, they have got just about everything else there.
BTW they keep many species of wild animals on public display, so I think I would call it a zoo even if they don't do so themselves.
As a legal definition, i.e. "zoo" = an institution displaying animals all year long for the (paying) public, you are correct. In German (or should I say "Teutonic"?) habitual language use, however, most people differ between a "Zoo/Tiergarten" (= an institution with focus on exotic animals, in particular exotic megafauna, and often within or close to a larger town/city) and a "Wildpark" ( = an institution with focus on native wildlife [usually also displaying some smaller exotics] that is often located in the countryside). ► Zoo-Infos.de ◄ - die Zoo-Datenbank