Ya, and also that there are all threatened ( on of them is already extinct in the wild ) I would think they would breed a lot better in there own separate cages in there own herd. There are always risks, even in a same species herd, but there are higher risk when you place different species together. Zoo now a days shouldn't be taking those risk with such delicate gems.
Addras and Scimitars are a lot hardier than you might think. They do quite well in mixed species. If breeding is happening on or two species are removed from the mix, simple.
@Jdndsn99 - I totally believe u 100% but could you tell me why these two are hardy. Is the Goitered Gazelle also hardy. If not why? They all live in extreme conditions. Thank you
Just because they are endangered doesn't make them fragile. There are thousands of SHOs and Addras living on ranches in Texas.
As for the Goitered, it is a phase-out species (at least the Arabian subspecies which this is). There are only 3 places in the Us that have them and one of those (San Antonio) keeps theirs off exhibit.