I've worked at three Aussie zoos, and in my experience (for the species we have in Planet Zoo):
* Kangaroo and wallaby mixes work well and are very common in walkthroughs, even with red kangaroos. If you wanted a really realistic design, include a separate roo yard that is closed to the public - we would move any roos/wallabies that didn't like being in a walkthrough into the roo yard and they would happily live there. Red-necked wallabies are very sweet and calm natured (compared to your rock wallabies, for example, which are highly strung and flighty). Red kangaroos are much more docile than their reputation and usually just lounge around.
* Wombats are nasty! They need their own space, and should not be in a walkthrough area, or in a mixed exhibit. Even our lovely little hand-raised girl was a hazard, she'd run into your shins for fun... the mean ones bite, and run into your shins out of malice. They bite other animals too, and have been observed as particularly awful to koalas.
* Emus can be included in walkthroughs, they're very friendly to people and other animals.
* Koalas should be housed either as single males, or groups of compatible individuals. We wouldn't mix them with other species, only because they have to have super clean eucalyptus branches and they can also be pretty grumpy. Can be in walkthroughs, but are typically not (I guess because people hassle them, but also because they would climb too high to be seen).
* Flying foxes (I know they aren't an Aussie species in game): these guys used to be staples in a few walkthrough aviaries, but after some Hendra/Lyssa virus scares across the country they have been removed from walkthrough aviaries in my local zoos. Still very popular in nocturnal houses or aviaries with no walkthrough function (they're active during the day, so they work in or out of a nocturnal house).
* Dingoes definitely can't mix with other species! They're intelligent, athletic and would hunt anything that moved. Very friendly with people (if they're zoo-born dingoes), but not used in walkthroughs. They could bite a zoo guest, but mostly you'd have them in their own enclosure because it emphasises that dingoes are not just feral dogs, but their own important species of Australian wildlife.
* Saltwater crocodiles - Usually single housed, or in a compatible pair.
* Platypus: Most commonly in their own enclosure, sometimes with a nocturnal house setup or an indoor underwater viewing area. They're super shy, so you need a small and quiet setup to be able to see them reliably in a zoo. They can also be kept in walkthroughs with birds/kangaroos/wallabies, but again they are extremely shy so visibility is poor (almost always hiding in burrows).
* Cassowary: Definitely not with other species. Keep either a breeding pair in one enclosure, or single house two birds in adjoining habitats (even if you are slowly introducing a breeding pair).
Hope that helps for any realistic builds! We have a good number of Aussie representatives now!
Also, if we ever get tassie devils, they will eat anything and everything, so definitely need to be housed in a pair or individual enclosure. I can't believe the zoo you mentioned would keep them with roos/wallabies!! That would surely be a feeding frenzy, yikes. Maybe they just had a really seamless exhibit design that made them look like they were together?
). The wombats have their own enclosure, so does the koala. Also the cassowary although I think I read somewhere they can be kept with wallabies. Which seems strange, since it is a dangerous Bird.. please share your experiences.
