That's presuming they have enough space to hold either three or four animals- if not then they should designate which other Zoo would hold the 2nd pair if they ever have the luxury of such a decision again.
That`s the irony of the whole discussion - from what I know, Cincinnatti DOESN`T have space to hold more then one pair of sumatran rhino, and even this housing is rather small. They sent their offspring away rather quickly to make space for Emi`s next calf. The thought of a larger sumatran rhino program in the US is ridiculous because the only zoo that has the expertise to breed them has no space for more then one pair, and if a breeding program is to work, the best way to ensure it is to house multiple animals so that pairs can be established that are actually compartible. I think it was a huge mistake to distribute the rhinos that came to the US/Europe to serveral zoos incl. one (Port Lympne) that was on another continent; they should have concentrated them all in no more then 2 zoos, ideally not far away from each other to make exchanges easier.