Want confirmation, at RainForest Adventures Discovery Zoo but this zoo is somehow the only holder of the species on ZTL. Probably belongs to the "Eulemur rufus (Eulemur rufifrons in part)" on ZTL
Only reliable way to know that is to know where this zoo got them from. If they got them from the wild, it may be pure. But if they got them from another zoo (which is most likely) they're probably the same as the other ZTL-entries