Wild water buffaloes are on the Red List of threatened species of the International Union for Conservation of Nature and Natural Resources, with fewer than 4,000 remaining across Asia. Unlike many introduced species, they fill a unique niche in the wetland ecosystem.

Hongkongers' attitudes are divided towards these friendly and normally placid beasts, whose existence is under threat. Things came to a head when a visitor was injured by a buffalo on Mui Wo beach recently. Spooked by weekend crowds and disoriented by temporary fencing that blocked its usual path to the beach, the animal gored a tourist in its haste to escape. It was killed, along with two other animals, by Agriculture Fisheries and Conservation Department (AFCD) officers. Three now remain in the 40 hectares of wetland behind Mui Wo, and it is their fate - and that of some 30 to 40 others at Pu O, Shap Long and Cheung Sha - that is exercising the AFCD, SPCA and local residents.

The rural villagers who once owned the buffaloes have distanced themselves from the animals. 'They don't really care any more. The people who come to live on Lantau in recent years care more,' say Ho Loy, director of the Lantau Buffalo Association. 'Although some of the older generation used to own them, they have given up farming and so, in a way, given up the relationship with the animals.'

The younger generation are landowners and don't care about the buffaloes, she adds. 'They want to build on the buffaloes' wetland. They are trying everything, big and small scale - scraping the landscape, putting land on the market, making development proposals to government.'

Meanwhile, complaints are common - about buffalo dung and buffaloes blocking car parks - along with demands for compensation for alleged damage. Many people complain about buffaloes and cattle damaging vegetable gardens, although these are often unfenced and occupy government land illegally.

One man's dangerous pest is another's tourist attraction. At the Mai Po Wetland Reserve, two buffaloes are a popular visitor draw. The female was introduced in 2006 and the male in 2009, to graze on vegetation in the wetland.

'They add great ecological value,' explains reserve officer Katherine Leung Kar-sin. Their weight crushes vegetation, creating more habitat for amphibians and making it easier for visitors to see the birds. 'The insects on their backs attract white egrets. They make a very positive contribution to the eco-system,' she said. And it costs far less to have animals eating the coarse grasses and weeds than paying people to cut them.

'There's been great media interest, and the public has helped give them names: it's very good publicity for us,' Leung said. 'People love looking at animals, especially if they are happy and kept in good conditions.' She is conducting a study into the benefits associated with buffaloes. 'I hope we will get more [animals] soon. We have been approached by the government about the three at Mui Wo.'

In short, buffaloes help keep wetlands wet, as David Dudgeon, professor of ecology and biodiversity at Hong Kong University, explains. 'They are endangered - and to think we are basically killing them off in Hong Kong. They are not doing any harm,' he said. 'They have value: they are culturally part of the countryside. Wouldn't it be nice if children could see them? They graze in a heterogeneous pattern. They are bioengineers because, by creating hollows which fill up with water and by wallowing, they keep the wetlands wet.' When buffaloes disappear, as in Shui Hau on Lantau, the wetlands can be seen drying up.

'Buffalo pools create habitats for other species, such as birds, insects and amphibians. They enhance biodiversity,' he said. It is ironic that the AFCD says it wants to conserve freshwater wetlands but seems set on eliminating the buffalo, he said.

The department's policy takes a threefold approach to the buffaloes - relocation, desexing and education - says chief AFCD veterinarian Dr Howard Wong. Relocation refers to moving the three Mui Wo animals to Mai Po. As for desexing, 'approximately 22 have been desexed since 2007 by the SPCA and AFCD, to control populations, especially in areas like Sai Kung', Wong said. As for educating people about the animals, the AFCD will conduct a campaign by mailing out pamphlets.

But the AFCD has a dismal record with regard to Hong Kong's hapless buffaloes. In 2007, government vets attempted a buffalo cull in Mui Wo. Seventeen animals were rounded up, tranquillised and loaded into trucks. 'There were adults and small calves. They were somehow loaded on top of each other and the ones on top crushed the ones beneath,' said a Mui Wo resident who asked not to be named. 'The anaesthetic dose has to be just right, or they bloat and die', he added. 'It was a combination of bloating and squashing, and by the time the trucks reached the New Territories, only one was still alive. It was horrible - 16 of the 17 were died.'

The department has since improved its methods, Rupert Griffiths, the SPCA's welfare research and development manager, says. In Sai Kung, the AFCD is supporting a herdsmen's scheme in which 20 uniform-clad, trained volunteers are on call to deal with problem bovines.

What future lies in store for the beleaguered buffaloes? Mui Wo residents have approached Hongkong Land, the owners of a sizeable part of the Mui Wo wetland, about establishing a wetland reserve for the animals. But the AFCD opposes any such plan, saying it would be unworkable under existing frameworks.

Mui Wo's three bachelor buffaloes are destined for de-sexing, says Griffiths. The AFCD is waiting for further word from the Lantau Buffalo Association before deciding whether to relocate or cull them. If they are to be relocated, their new home at Mai Po is not ready, so they would first go to an interim site - one without water, which is clearly unsuitable, says Ho.

Mui Wo resident Diane Stormont argues there is no need to move the animals in the first place: 'There are only three buffaloes left and more than 40 hectares of scrubland and wetland. There is plenty of room for buffaloes and humans to co-exist peacefully.' The SPCA's Griffiths says whatever happens, 'we will be there to take care of the animals' welfare'.

Ho thinks the buffaloes should be given protection as 'distinguished species'. 'Three parties - the AFCD, SPCA and local residents' groups such as the buffalo association - should decide what's best for the animals, the humans and the environment.'

50%

The expected decline in the population of wild water buffalo across Asia in the next 21 years