Currently, WII makes use of different types of collars on tigers to study them in different terrains. Currently, 10 tigers in Kanha, two in Sariska and one in the Sunderbans are fitted with satellite collars.

Tigers in Pench and Ranthambhore are fitted with Very High Frequency (VHF) radio collars, while two tigers in Ranthambore have GPS (Global Positioning System) collars.

The number is likely to increase, with NTCA roping in different NGOs to collar more tigers. More camera traps, depending on terrain, will be set up.

“We are increasingly making use of technology to help us understand tigers better. Through this kind of monitoring (through collars) we can ascertain how many litters a tigress can give, age-sex dispersal over landscapes. The move to create and collate nationalised systems of data will give us a much broader perspective,” says Qamar Qureshi, senior scientist from WII who has been involved in many tiger collaring projects.

The different collars

• Satellite collars: costs Rs 3 lakh each; fitted onto tigers over difficult terrain. To conserve battery, the signal and GPS positioning come on at specified time (when the satellite is within 500 km radius); can transmit data to the satellite directly

• GPS collars: costs around Rs 2 lakh each; transmits positioning (location) data to a receiver which will be around half-a-km away from the source

• VHF collars: costs around Rs 10,000 each; have been traditionally used. They work by giving radio signals