The 1992 IUCN list of mammals in the AB evaluation includes all 5 (of which buffalo, elephant and leopard were present "on the crater rim" 9but (but still within the inscribed area) whilst Rhino and Lion were "in the crater". As of 2009 it is thought that all are still present, with the Rhino the most threatened.

Lewa Wildlife Conservancy: It ... includes the big five (lion, leopard, elephant, rhino and African Buffalo) (wiki)