THE TIGER census has been used for long as a convenient official yardstick to measure the success of national park management. But a dispute on the exact tiger population has set a census under way in Ranthambore national park that has the authorities on edge.

Since Project Tiger was launched in Ranthambore in 1973, the number of tigers there has risen steadily and set at a record 45 in 1991. But this figure was questioned in 1992 following reports of poaching and park mismanagement. A re-count conducted by the Rajasthan forest department and for the first time, a non-government organisation, the Ranthambore Foundation, put the tiger population at just 17. The Ranthambore Foundation independently said the figure was between 15 and 20.

The forest department, however, rejected its own low figure and cited defects in the census, including that the staff deployed was too small and largely untrained, the entire park was not covered, and the re-count was held at a time when the tigers had retreated into remoter parts of the park, following a good rainfall in 1991.

R S Kumat, principal secretary of the state revenue department, was appointed to look into the case of the missing tigers and his report, besides endorsing the department's views, also suggests census methods should be more rigourous and verifiable.

The latest census, which began in May, has the Ranthambore authorities jittery, because the Supreme Court has directed the state government to fix responsibility if there is any decline in the tiger population. The directive was in response to a public interest petition filed by tour operator Lynn Fernandes, who contends tigers are seldom sighted in the park.

The present census uses a refined method of counting, involving "tracing pugs and counting them instead of taking plaster casts." Says Ranthambore field director B L Meena, "Plaster casts are difficult to take, especially in the soft mud around watering holes frequented by tigers."

The Ranthambore Foundation and the World Wide Fund for Nature are monitoring procedures and adherence to census rules. Says Valmik Thapar, a wildlife expert and an independent observer of the census, "This is testing time. A lot is at stake because the result of this census will have a crucial bearing on the conservation strategy followed so far in the country."