Black Rhino - we have both Eastern and South-central
There's population lists on ZC for them, probably the easiest way there.
Red Panda - I know we have Nepalese and Chinese, and people have been adding to both - with no overlap so far. I don't know the type for any that I've seen, how are people entering these?
They're generally fairly distinct in coloration, as Neil has noted. Typically zoos do keep one or the other, but there's a couple with both.
Hystrix - are we assuming that all AZA are africaeaustralis, even when they are signed cristata?
Per studbook, almost all are africaeaustralis, Neil has listed the exceptions. I do not doubt both are in the private trade and should be identified carefully for non-AZA. A large number of places are currently listed for the wrong species in ZTL. I posted the link to the thread discussing ID points earlier in the thread.
Ocelots - I know that some zoos have mitis, but I'm not sure which ones
Brazilian Ocelot at the following:
Abilene
Alexandria (Brazilian & generic)
ASDM
Assiniboine Park
Audubon
Beardsley
Bergen County (Brazilian & generic)
Buffalo?
Cincinnati (Brazilian & generic)
Cleveland
El Paso
Elmwood Park
Franklin Park
Houston
Hutchinson
LA
Mesker Park?
Oklahoma City
Orange County
Palm Beach
Santa Ana
Gray Crowned Crane - should these be at species level or gibbericeps?
I've heard all ours are Eastern, outside AZA included.
Common Ravens - should these be species level, or are all of ours probably one ssp?
There are 4 subspecies north of Mexico, largely separated by size variations. I've seen at least two subspecies in zoos personally, and unless you know origin location, probably not listable to subspecies.
Rhinoceros Hornbills - all just species level?
This is one I'd like to know as well, I've not been able to find anything out so far.
Outside the AZA they will all be africaeaustralis or perhaps hybrids (of mostly africaeaustralis ancestry).
Not true - Austin and Hemker hold them, as Neil already noted. Would not surprise me if there were others.
They are also know to have produced white tigers, so ZooMontana's sister pair are almost certainly not pure Amurs, despite the claims made on the website.
The studbook says generic, so definitely not pure Amurs. Zoos tend to claim a lot of things re tiger subspecies that aren't necessarily true.