@Onychorhynchus coronatus I believe zoos with Yellow-Backed Duiker often exhibit them mixed with Okapi, though usually give the duikers a small space to hide away from the larger animals if they need/want to. I've also seen Black Duiker mixed with Okapi on a couple occasions.
@ThylacineAlive Yes, I think its a good idea (particularly educationally for visitors to see these two species from same habitat together).
I know that the okapi at the London zoo are kept successfully with a species of duiker, saw both of these during a couple of visits, but don't remember the duiker species.
@ThylacineAlive This is a bit of a thought experiment but do you think a primate, perhaps a guenon species, could be kept successfully along with these two species within a large enclosure ?
@Onychorhynchus coronatus I'm not sure tbh. I think SDZ used to mix duiker and guenon but don't anymore. I don't think I've ever seen guenons mixed with hoofstock come to think of it.
An interesting conversation! Caldwell Zoo, in Texas, had colobus monkeys, bongos and a yellow-backed duiker all together when I visited in 2015 and in 2010.
Mixing blue duiker is a little more surprising to me, since they seem much more fragile than the larger species. That said, Bronx did mix their Maxwell's Duikers with colobus for many years, before exhibiting them with their Aardvarks/Southern White-Faced Owls until their passing in 2015.