Can't answer you as unfortunately I live too far away to be a Chester 'regular'. But I've never seen a Black jag in the Savanah side on any of my few visits, only the normal female, is it Sofia(?).
If I remember correctly when SOTJ first opened they only had the two Rome jags, Ebony and Carlo(s) - I think they would have been kept one in each side at this point.
1.1 in the savannah side (Sophia and Salvador) were supposed to be a breeding pair, however their first litter was stillborn and I think a second litter only lasted a few days. Therefore, the EEP recommends that these don't breed (for fears it may be a genetic problem between them?)
2.1 in the rainforest/waterfall side are father/mother and son from Marwell. Pele the melanistic jaguar from the rainforest part indoors is the father, whilst Wanetta is the mother and Coral is the son. Coral has been doctored to prevent inbreeding, and these live as a surplus holding that Marwell had no room for.
At the moment, there are no plans to breed any jaguars from current holdings. I think the plan is to wait for one of the groups to pass on before replacing with a breeding pair that will hopefully have more success.
I think this is right, but don't take it as 100%. It is possible I've got a fact wrong or misunderstood, so if I have then anybody feel free to correct it