OK, then replace Serow with Sika Deer... My point was hoofstock in general...That's actually not the case, Japanese serow are pretty rare in zoos.
I love the look of Japanese Serow, whereas Sika is a mini red deerlike animal.
About the Rhea, I think we have representatives all the other big flightless birds so why not? Its far from exciting but it would complete the roster more.
Lastly, Nilgai >>>>> Blackbuck (Nilgai is unlike other antelopes in game and if we got him I wouldn't be so desperate for the eland anymore)