If you only have a couple of hours maybe the zoo would be better, as everything is closer together, so you can get between the things you most want to see more quickly (but you won;t be able to see everything in less than a day, so plan and prioritise ahead).
The bird of prey aviaries are undergoing renovation and, as such, are empty. All of the captive waterfowl, penguins and 'park birds' are indoors so all the ponds and paddocks are empty (plenty of wild mallards though). The carnivore house is virtually empty (a solitary lioness, no tigers, a couple of leopards and an ocelot - plus those in the small carnivore wing). The area immediately behind the giraffe house (formerly housing deer) is a building site. The single remaining polar bear spends most of the day inside.
This is possibly the most depressing paragraph I have ever seen on Zoochat....
Rob, contrary to most advice here, if I were you I would still hold on to the Berlin weekend and spent it at Tierpark and the Naturkundemuseum and perhaps Museum Insel. You really need not visit the Zoo and be depressed. Instead you could wander the great outdoors on Tierpark's landscape.I was thinking of booking a weekend in Berlin for my birthday: I just changed my mind.