I'm not sure what they're called, is it studbook? How would you be able to find a list of the members of a particular species in captivity? or do you have to go via all the separate zoos? Thanks, there's probably an obvious answer, but oh well. More satisfaction for you!
Most people use ISIS; ISIS :: Home -> find animals. ISIS is created by the data that is being put in by their members, which are zoos. The information on it is therefore reliant on the amount of effort zoos take to keep ISIS up to date. It also contains a few obvious faults that are not being fixed. Therefore, a group of German European zoo enthousiast made up the site; ZootierlisteHomepage which is completely reliant on zoo enthousiasts filling in the information. It therefore is reliant on the efforts of enthousiasts and also not completely accurate. The best is to use a mix of both, together with information asked on sites like this. Particular species studbooks are being kept by studbookholders. They are sometimes listed on websites of the zoos that these people work, or other websites. If you can get hold of a studbook, they are usually really accurate but only to a certain date and only for one species. Many are hard to come by though, but the easiest way is to try and google, or ask on zoosites...
I use both ISIS and ZTL for things like this. Speaking of ZTL are there any plans to add zoos from the USA and elsewhere at some point? Maybe a world zoo database instead of just European collections?