HOW ROBUST IS INDIA'S TIGER CENSUS

During the 50th anniversary celebrations of Project Tiger on April 9 this year, Prime Minister Narendra Modi announced that the animal's population in India had increased to 3,167. Less than four months later, on July 29, a new set of numbers were released that pegged the population at 3,682 tigers; over 500 more than the April estimate. This has sparked debates over the accuracy of tiger census. RAJAT GHAI speaks to government officials and independent experts to decode the riddle of tiger estimation:

- RAJAT GHAI

"We are not here to inflate tiger numbers"

QAMAR QURESHI

CO-AUTHOR OF "STATUS OF TIGERS CO-PREDATORS AND PREY IN INDIA 2022"

Estimating tiger numbers is a huge exercise, with more than 40,000 people involved in data collection.

The first phase of data collection happens at the beat level. The whole of India is divided into 15 square kilometre cells. From each beat, forest guards, volunteers and daily wagers collect data about tigers, leopards, other carnivores, ungulates, large herbivores, vegetation and human disturbance. They use an application to take pictures, collect data and then upload this data in local languages. This then gets translated into English.

Secondary public data and satellite remote sensing data is used for modelling. In phase three, forest department staff and researchers collect camera trapping data including tiger pictures with the help of traps installed across India. We then use artificial intelligence (AI) to sort out those pictures that only feature tigers.

These photos then go through another AIbased programme that identifies individual tigers. Finally, a round of cross checking makes sure everything is in order. We then run models to analyse the data. We thus have data for 83 per cent of the tiger population. The rest is extrapolated.

There is always a margin of error. That is why we use human intelligence as well.

As for murmurs of discontent, people have a lot of misconceptions about the tiger estimation process. We are not here to increase or decrease tiger numbers. Our job is to be as authentic as possible.

Of course, we are human. So, there will always be mistakes.

A common mistake people do is adding tigers. For example, you have two locations which have tigers.