@Newzooboy mid 1999 im certain, the maps got all colourful and almost identical to the way they still are just at the end of 1999. The Silvery Gibbon and Red Panda moved to where they are on the map here in mid 1999. The new female Cheetah arrived at the end of 1999 from South Africa and would in the next maps after this between Lion and Hyena exhibits. Notice number 21 next to 22 Sumatran Tigers is not identified on the map. At this point 21 would of been Persian Leopard and next door temporarily home to what remained of Perth Zoos 1980s/1990s African Hunting Dog pack. The poor Persian Leopards really only ever got a footnote menton on zoo map or species list information from the late '90s to their departures 2001-2002.
This map wasn't an official Perth Zoo map but was a page insert in the StreetSmart street directory. I worked with Dept Planning on the layout in late 2000/early 2001 so @steveroberts wasn't far off.
