Global tiger day
Biodiversity Environment Forestry

Insights into Status of Tigers in India 2018

With 593882-man day efforts, 522996 km of foot surveys, 317958 sample plots, 26,838 camera trap locations, 35 lakhs of wildlife photographs – our country finished its fourth cycle of Tiger estimation (Status of Tigers, Co-predators & Prey, 2018).

This is also the largest Biodiversity survey the world has ever witnessed, the results of the survey were more satisfying and astonishing. The results made into the headlines of almost all the global media and created a buzz all over the world. But except the people involved in this survey only a few others know about the herculean process which lead to these fruitful results. It is equally important to know about the process as knowing the results.

In India there are 50 Tiger reserves which occupy an area of about 72749 km2. This area is divided into five major Tiger landscapes. And the survey says that India have 2967 Individual Tigers (<1 year of age).

Pushing Technological counting

The first ever Tiger survey of our country started in 2006 with so much input and reviews from international experts. At that time the complete data collection is mainly based on the foot survey. At that time the use of camera trap method was uncommon. Then the data is processed manually. And after processing the data with the help of statistical analysis the approximate number of tigers are worked out. In the subsequent surveys, the technological advancements began to bring changes slowly in the entire survey process.

In 2010 survey, a software called M-STrIPES has been developed by the Wildlife Institute of India. This computer software eased the way of processing the data collected with M-STrIPES manual from the field. In this survey also camera traps were not used in all the tiger reserves. This survey method is also susceptible to human errors. Then comes the 3rd cycle of tiger survey, 2014. In this survey camera traps were used in almost all tiger reserves but in less density while comparing the present survey. 2018 survey standout from the other surveys mainly because of digital advancements. Digital India !

Tigers superheroes

How 2018 survey differs

The 4th cycle of tiger assessment is the most accurate survey ever conducted. This is possible because the whole survey process is digitalised. Firstly, the manual M-STrIPES record used during the foot survey is converted into an android application with the same name and for which each forest guard working in tiger reserves were provided with an android phone. With this the whole data collection work is digitalised. And then comes processing work. In this survey, 35 lakhs of photographs were taken by the camera traps. These cameras work on the principle of motion capturing and capture all the moving objects in front of them including a falling leaf. Processing camera trap images starts with segregation of images i.e. Tiger photos are separated from the others photographs of various species captured. Imagine the size of 35 lakhs photographs…!

To make this possible, a new software called CaTRAT (Camera Trap data Repository and Analysis Tool) is developed. The work of this software is to segregate photos of each species and geotagging them. Of this 35 lakhs photographs only 76651 were of Tiger’s and 51777 were of Leopards. With the help of this, time taken for photo segregation was drastically reduced. Next, of these 76651 Tiger images, individual tiger images should be separated. Here comes the software called Extract Compare. Each tiger is identified by their stripes pattern and these stripes are like their fingerprints. This Extract Compare software extracts the stripe pattern from each tiger photo then analyze it and compare it with the other photos to identify individual Tigers. Once a Tiger is identified the details regarding it were saved in National Tiger Database. (For leopards a separate software called HotSpotter is used, it is based on the leopard’s rosette pattern). Of these 76651 Tigers photos alone 2461 individual Tigers (>1 years of age) were identified. This will be a most valuable data in the near future. Because this software provided us with digital stripes pattern of 2461 Tigers (>1 years of age). This will be helpful to identify Man Eaters or Killed Tiger where poached Tiger Skin itself can trace the Tiger’s origin even without an enquiry.

The Grey Area

Wherever the Tiger numbers are mentioned in this 2018 survey, one may notice that tigers counted were more than 1 years of age. This implies that in addition to the 2967 adult and adolescent Tigers there are also young Tigers which are less than one year of age. These young tigers were excluded from the counting. This reason behind this will be a dependency of the young ones on their mother. But the real question arises while comparing it with the 2014 report. In 2014 report tiger census was taken into account of tigers more than 1.5 years of age. The explanation of this change was not available in the recent report. Is this a serious flaw? Young tigers become independent only between 17-24 months of age. So, as taken in the previous report 1.5 years of age will be optimum to count the Independent Tigers. This five months’ period will definitely add some numbers to the final count of the tigers.

On the whole, comparing the 2010 survey report both 2014 and 2018 lacks detailing. Both these survey’s reports look like a summary. The 2010 report gives the details about the number of Tigers in each Tiger reserve on the other hand both 2014 and 2018 reports give details on the State wise numbers. The 2010 report talks about the corridors, co-predators, ungulates and major problems of each Tiger reserves while the latest surveys lack each of this information.

When one gots cent percent marks in an exam who cares about their handwriting. As of now, the Indian Tigers are on the right path of conservation. Nothing to worry. But micro-detailing in report will be a help in policy making and future conservation efforts.

Editorial by Muthumani, Forestry graduate and special reporter of forestry to IMoT Agri Forum