Adam Barlow, resident scientist of a pioneering tiger conservation project, tranquillised the 125-kg tiger around 4:30pm at Katka in a bid to gather more information on tigers by monitoring their movements.

On April 22 last year, he tranquillised a 14-year-old tigress, Jamtolar Rani, at Katka in Jamtola in the Sundarbans. She later died.

The collar comes with Global Positioning System (GPS) technology to monitor her location. The collar also emits a radio signal allowing experts to follow her moves.

The best way to get information on tigers is to track them on daily basis using radio telemetry. This method has been proven effective over 30 years of research on 70 tigers in four countries, experts said.

Wildlife protectors have to guess their activities and guessing is far too risky an approach to save an endangered species since there are only 5,000 to 7,000 tigers left in the wild today, they noted.