I think they should use this part of the enclosure for the pygmy hippos, they could maybe even put underwater viewing in the dry moat. Then the hippos wouldn't spend all winter in the tiny enclosure they do now.
Radical suggestion: why not bring back a pair of [Black or Indian} Rhinos, devote all the Casson outside paddock space to them, and use the remaining indoor bays for indoor stuff that can use the height [hornbills, pythons?] ?
I was speaking to someone who used to work with the elephants and rhinos here, and only a few decades ago they were rotating Northern White, Indian and Black rhinos around the whole area the pigs have today; amazing to think back on now.
I think London works well without necessarily needing rhinos now, which would need quite a bit of space where you could house several more urban-suitable species to be kept well, but with the seeming mergence into the tiger development I like your other idea.
