Shocking facilities: Melani, a severely underweight Sumatran tiger, is wasting away. Credit:Michael Bachelard Last year the world was alerted to the problems at the zoo in Indonesia's second-largest city when a giraffe died and was found to have a 20-kilogram ball of plastic in its stomach. Last month, Rezak, another Sumatran tiger, died. He was old but also had lung disease contracted in a tiny, permanently damp, cage. ''The holding facilities were shocking, wet all the time,'' says Tony Sumampau, the head of the Indonesian Zoological Parks Association and now a consultant to the zoo. ''Most of the animals … died because they got pneumonia, lung disease, TB, or from digestion problems because of the food supply.'' When we visit the zoo, we see proboscis monkeys, in-bred and overpopulated, roaming freely in public areas and scavenging for food among the spillage from garbage bins. Barbary sheep chew on plastic bags. Monkeys argue over an ice-cream wrapper that blows into their enclosure. More rubbish floats by in their moat.

These conditions, though, are a vast improvement on what the animals endured three years ago. ''There was an internal conflict among the management, and the staff were … divided too,'' says curator Sri ''Penta'' Pentawati. ''They took sides and … were more focused on the conflict than caring for the animals.'' The result was horrific. The cages, some built in the 1920s, were tiny and fraying, the animals so in-bred that deer had antlers growing out the front of their heads. The pelican cage is seriously over-crowded now, even after 70 birds were given to other zoos. Endangered Komodo dragons grew up with kinks in their bodies from inadequate space and sunlight. Two cheetahs, gifts of the South African president, were killed because they were housed with tigers. One staff member was using the zoo to breed ducks; the camel-keeper's second wife was living in the camel shed so his first wife wouldn't find out about her, and a sooth-sayer was selling advice from the hippo enclosure.

Many employees claimed to be ''pawang'' people with a magical ability to control the animals, but as the animals died, they were making a killing. The meat was supplied by a staff-run business. They bought it cheap (laced at the market with the illegal preservative formalin) then sold it at a big mark-up. Sumampau suspects formalin is responsible for Melani's digestive distress. Another staff-owned company cut weeds from the side of the polluted Surabaya river to sell for herbivore food. The zoo's entrance fee was just 4500 rupiah (48¢) per person, but even from that paltry income, the former owners took a profit. In 2010, as the bad news mounted, the city government sacked the management, installed temporary leaders and brought Sumampau in as an unpaid consultant. The entrance fee has more than tripled, the Komodos released from their tiny cage, the orang-utans and monkeys given redesigned shelters and the tigers new holding yards where they can move. Rather than spending up to 10 days in tiny holding cells for every three days out on display, the tigers have more space, sunlight and exercise. In the face of strong local opposition, which views a large number of animals as a sign of success, the zoo is trying to swap out over-populated species and bring in fresh blood-lines. Last week a young male giraffe arrived from Germany to form part of an African exhibit, a vote of confidence in the new approach. Asked if she could guarantee it would not die like the last one, curator Penta says: ''We will try our very best to minimise the chance.''

Penta has been at the zoo for 19 years, but has a strong desire to see change. The obstacles are enormous. The staff, many of whom have been there for 30 years, are still highly resistant to new ideas. Keeping the grounds clean of rubbish seems to be an insurmountable challenge, and many displays need radical renovation or rebuilding. That takes big money, but it's in short supply and there's no ready source. ''We need 100 billion rupiah [$10.3 million],'' Penta says. ''All we can do is try to find private sponsors.'' Three years after ''temporary'' management was installed, it's still in place. Sumampau is also frustrated with the slow pace of change: ''Melani should have been euthanased two years ago, but people say, 'You're not trying to treat the animal, you just want to kill them'.'' Singleton, the director of the Sumatran Orang-utan Conservation Program and a former zookeeper at the Durrell Wildlife Conservation Trust, says Indonesia's 40 zoos are ''still highly unregulated and simply milking the small entrance fees''. All but a handful fail to meet international standards, he says. But Sumampau still thinks Surabaya should be given a chance to avoid having its prime city acreage turned into yet another shopping mall. Zoos are massively popular in Indonesia, and one of the only sources of cheap entertainment for ordinary people. About 7000 people visit Surabaya each day of the weekend and, on big holidays, it's perhaps 40,000.

''There are many animals and the trees are very fresh,'' says Rizal, a mechanic from nearby Madura, visiting last week with his brother and their families. ''If we stay in here we get to freshen our brains.'' But Sumampau knows that only with significant private investment can it work.