I believe all the zoos in the Australian region should do more to house South American species, Melbourne especially, they use to have one of the best collections. However as much as I would love to see growing wild redeveloped, it seems highly unlikely. For starters the precinct is quite new, and the zoos uses it educational facilities on the daily to teach younger children.
For me there are 2 places where a South American area could be developed.
Gorilla Rainforest or Forest of wonder
Calling the precinct forest of wonders, makes me hopeful that it will features more than just animals from Asia.
They could redevelop the Elephant enclosures into a mini amazon precinct, this would be costly, but could the the most rewarding. The species that could take centre stage being Baird tapir, sloth , capybara and a variety of monkeys species . Some animals could have separated enclosure and other joined togeather.
They could use the treetop apes and monkeys ares, it would be smaller, but would be more affordable.
What I see happening is possibly Tapir, capybara and spider monkey in the enclosures this could mean they would make minimal changes, they would then once they have the money overhaul the area
In the current state, Treetops seems the most likely given it lends itself to arboreal species like sloths, which will hopefully soon be available to the zoo. With renovations, it wouldn’t be hard to integrate Brazilian tapir and other terrestrial species into these plans; though I remain of the belief the old Malayan tapir exhibit would be the best place for them (with the nyala either housed with the giraffes; or in the adjacent old bongo exhibit).
Multiple exhibits for tapir (at a minimum two to house a male and female seperate) would be beneficial for breeding; so long term, they could look at housing them in the adjacent Collared peccary exhibit (in addition to the old Malayan tapir exhibit).
Alternatively, the peccaries could move out and the whole row could be redeveloped for two Brazilian tapir exhibits (plus BOH).
Collared peccaries could go:
A) Ground dwelling in Treetops
B) Old Eastern bongo exhibit
C) Werribee - simple exhibit that could easily be redeveloped when they pass on
