May 27, 2019

Counting on a Tiger

Many of the things you can count, don’t count. Many of the things you can’t count, really count.

— Albert Einstein
Forest Camp view – by Sohail

1.3 billion* People living on 2.4% of the world’s landmass constituting 17.3% of the population. This is called India.

2226 Tigers ** living on 2.4% of the world’s landmass constituting 70% of the population. This is called India. 

‘Counting is the process of determining the number of elements in a finite set of objects.’

The human population is counted one by one until we have counted them all and arrived at a number.

With Tigers it is not that easy. The cat is shy, difficult to identify and occupies varied landscapes.

Hence a different approach has to be taken.

News Highlights

  • Undertaken every 4 years it’s the largest wildlife survey exercise to be conducted in the world
  • The latest tiger census is currently in its last phase which begun in 2018. Tiger population figure to be out by June 19.
  • Nepal, Bangladesh and Bhutan have become part of the Census from this time. A positive step for tiger monitoring and protection in the Indian subcontinent.
  • 10 crore (100 million) INR is the cost of the entire exercise.

How is it done?

The method adopted to conduct the Tiger census is double sampling method. The first sample is collected by the forest staff of all Tiger Reserves following the methodology and protocol laid out by National Tiger Conservation Authority (NTCA) and Wildlife Institute of India (WII).

The second sample is collected by biologist from WII.

Data is collated and viola we have Tiger numbers in India.

So are we done? Do you all want to go more in detail?

Curiosity kills the cat. I am telling you, you will regret this.

Ok your choice.

The Tiger Census involves 4 phases of data collection.

The fun part

Phase 1

Activity split over 6 days. First three days are dedicated to carnivore signs survey, the next three to herbivores, vegetation and human disturbances.

Carnivore signs survey:

15 kms of paths are traversed, 5 kms each day on the paths. These paths are selected strategically based on the movement of Tigers.

The objective is to look for the carnivores and their signs. Signs would include pug marks, scat, scrape or scratch marks and signs of a kill.

This data must be recorded with the corresponding GPS coordinates.

Signs of a Kill

This marks the end of Phase I.

Volunteers are invited to take part in this activity and you get a chance to stay inside the core area of a Tiger reserve in the forest camps.

I was part of Phase I exercise and it was as an immensely pleasurable experience. However, that story is for another time.

Let’s get on!

Phase II

The not so fun part

The NTCA obtains data from various organizations from which it will derive the characterization of landscape of the country especially where tiger signs are present. The data will be collated together to get tiger density in India.

Examples of the organizations from where data is sourced:

Human Footprint data from SEDAC (Socioeconomic Data and Applications Centre)

Forest cover maps from FSI (Forest Survey of India)

Phase III

Biologist from WII visit Tiger Reserves and collect the second samples.

Based on tiger signs obtained during carnivore sign survey in phase I, camera traps are placed and individual tigers are identified (every Tiger has a unique stripe pattern).

In places where camera trapping is not possible scat samples are taken to estimate minimum numbers through genetic analysis. 

Phase IV

As per NTCA protocol, Tiger reserves in India must monitor the Tiger and its prey on an annual basis.

The procedure for monitoring and capturing data is defined in the guidelines of the NTCA.

Hence for the 2018 census the 2017-18 data as maintained by the Tiger reserves as per the phase IV protocol will be used.

Phase I to III is done at every 4 year interval for country level monitoring.

The I don’t know part

All the data that we talked about above is collated and Tiger density is obtained on a map.

This is then translated into big cat numbers in India.

Forest staff at jungle camp

Conclusion

The double sampling method is criticized by few experts who argue that other methods which are more cost effective and accurate are available. Well I shall leave that to the experts.

With the resilience of nature and through protection and conservation there is hope for the tiger and it is likely that tiger numbers are on the rise. By how much is what we have to wait and find out?

For further details into the methodology and guidelines set by NTCA for Tiger census please refer to below links:

Protocol Phase IV monitoring

Tiger estimation brochure

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