"With the conditions of the existing threats, Sumatran tigers in Riau is predicted to become extinct the most quickly in five years. It may start from the extinction of ecosystems, where tigers are left no longer allowed to breed," said Osmantri from the Animal Trade Monitoring Coordinator of the World Wildlife Fund (WWF) in Riau.
The threat from habitat loss and illegal hunting are not comparable with the ability to breed tigers, the state-run Antara news agency quoted Osmantri as saying, explaining a female tiger can expect to live in the wild for 15 years.
During the lifetime, each individual can only give birth three times, he said. Sadly, only two maximum of the cubs are managed to survive until adulthood, while weak law enforcement is believed as the main cause of the difficulty of combating tiger poaching activities.
During the period 1998-2009, as many as 46 tigers were found dead as a result of man-tiger conflicts and illegal hunting, meaning that an average of seven tigers had been murdered every-year in Riau province. Only three cases of tiger poaching ended up in court in that period.
"But jail sentences handed down by the judges did not trigger a deterrent effect because the perpetrators are only punished up to one year in prison," Osmantri said.
"Law enforcement against poaching and killing tigers in Riau is the most weakest than other regions in Sumatra."
Environmentalists said the destruction of the species' natural habitat by illegal logging triggered the rise of conflicts between tigers and humans living in nearby forests.
There are between 300 and 400 Sumatra tigers left in the wild. The Sumatran tiger is believed to be the last remaining sub-species of tiger indigenous to Indonesia. The Bali and Java tigers are believed to be extinct.