The new census incorporates a range of additional assessment tools, including habitat evaluation, estimates based on available prey, and strategic placement of cameras fitted with motion sensors.
"The new survey is a unique effort that has never been attempted anywhere in the world both in terms of scale and effort," WII's Sinha said.
The important message of the new census, conservationists say, is that tigers are still dwindling in the wild and actions need to be taken to prevent their disappearance.
The majority of the world's tigers roam the jungles of India, and scientists there fear that the predator is hurtling towards extinction.
Poaching, habitat destruction, and the commercial demand for tiger parts have contributed to the tigers' decline.
(Related: "China Tiger Farms Lobby to Sell Animal Parts to Aid Conservation" [December 22, 2006].)
The Tiger Task Force, an expert group appointed by Indian Prime Minister Manmohan Singh, recommended the latest census, which launched in 2005.
WWF's Banerjee said that the government-led effort to understand the real status of India's tigers is a very encouraging sign.
"It is commendable that the government is stepping up for an independent scientific enquiry and that it is ready to accept the figures, however low they are," Banerjee said.
"Earlier, the census was carried out by the government itself. The problem with that was that [the government] would not want to report that the number of tigers had gone down, maintaining a sizable population where there was none."
In a statement last week Prime Minister Singh called for the "priority recruitment of frontline staff" to fill long-vacant forest guard positions to protect tigers.
Singh also recommended the creation of new development agencies within each reserve to stimulate local participation in tiger management.
Singh and other experts and regulators are expected to convene in September to discuss the preliminary results of the independent investigation.
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