Study Shows There May Be More Sumatran Tigers Than Previously Thought
The Jakarta Globe
Fidelis E. Satriastanti | July 17, 2012
Indonesia’s forests are home to at least 600 Sumatran tigers, a recently released survey has found, providing a more optimistic picture than a 1994 official report that put the head count for the rare species at between 400 and 500.
The latest survey was conducted from 2007 to 2009 on more than 250 square kilometers of forest covering 38 nature reserves.
“Sumatran tigers were detected in 27 to 29 nature reserves,” Hariyo T. Wibisono, chairman of the Harimau Kita (Our Tigers) conservation forum told BeritaSatu on Monday. “There are Sumatran tigers in those areas but the exact figure is still not known. [We] only know the distribution, in which [areas] they are high, low or stable.”
Hariyo attributed the higher figure not to an increase in population, but to a better extrapolation method. He said the method used in the 1994 survey was not as accurate as that used in the more recent study, adding that the earlier research surveyed only seven locations: five national parks and two conservation forests in Sumatra.
“The figure [400 to 500] was announced in 1994 and the counting was conducted in 1992. But after a population-viability analysis was conducted, it turned out the extrapolation method was inaccurate,” he explained.
To find out about the distribution pattern of the Sumatran tigers, several NGOs whose primary concern is to prevent the extinction of the species conducted the latest survey and publicized the result in a scientific journal last year.
A second survey covering 59 percent of the 38 nature reserves showed that Sumatran tigers inhabit 72 percent of the total tiger habitat area.
“Data compilation used to count the population came from camera traps set up by several NGOs,” Hariyo explained. “They showed there were at least 600 individual tigers. But this hasn’t covered all [areas].”
He said that counting tiger population with camera trapping was difficult due to insufficient resources given the breadth of land that needed to be supervised.
Hariyo said counting the tiger population was not as important as finding ways to protect the rare species.
“In protecting Sumatran tigers, information about their population estimates is not important,” Hariyo said. “What’s important is for the management to know whether they are increasing, declining or remaining stable, as seen from the indicators of their presence and distribution.”
He added that he was always careful about mentioning figures because of the methodology issues.
Dara, a critically endangered Sumatran tiger rescued from a hunter’s trap in Bengkulu in February, was transferred to the Taman Safari Indonesia park in Bogor earlier this month. The female tiger, estimated at 4 to 5 years of age, was found by officials in a logging concession in Mukomuko district. Her front legs were seriously injured from the metal cables in which she was ensnared. The trap was believed to have been set up by poachers.