India

Counting
Tigers in India

India is home to the world’s largest wild tiger population, despite being the second most populous country on earth. 
It takes an enormous commitment of time, resources and expertise to sustain wild tigers here. Every four years, the All India Tiger Estimation (AITE) exercise is conducted to estimate tiger populations across India, while also collecting important data on their prey and habitats.

The National Tiger Conservation Authority (NTCA) of Ministry of Environment, Forest & Climate Change, Government of India and Wildlife Institute of India led
the AITE in 2018. A total of 381,400 sq.km of forests were surveyed for tiger signs and prey estimation and 593,882 person days were invested into the exercise which covered 141 sites, setting a new global standard for large carnivore monitoring. The survey also delivered important results that tell us more than just how many tigers are living in India. WWF in partnership with the NTCA and State Forest Departments covered approximately one fourth of the sites.

Over to Dr. Dipankar Ghose, Director of WWF-India’s Wildlife and Habitats Programme, to shed some light.

 

What were the results of India’s latest tiger survey?

According to the latest results of AITE, released by the NTCA, India’s tiger population stands at 2967 individuals (SE 2,603 – 3,346).


What makes this estimation unique in comparison to previous years?

For the first time, camera trapping was extended to various sites and cameras were also installed at a higher density relative to previous surveys (one pair of camera traps in every 2 sq.km grid, instead of the earlier 4sq.km grid), as per the NTCA’s updated protocol. An unprecedented combined effort was invested in camera trapping with 381,400 sq.km of forest surveyed in total.


In such a vast country with numerous tiger landscapes, how do conservationists go about determining tiger populations?

The exercise involves surveys for carnivore signs and prey abundance estimation, camera trapping for tigers, and analysis of remotely sensed data to map the extent of tiger habitats and derive relevant variables on habitat quality and human impacts for analysis. These data are combined and statistical models are used to derive estimate of tiger populations and occupancy for tigers and their prey at site, landscape and national scales.


It is a huge investment of resources. Why do we count tigers? Does the survey give us any other important information?

We estimate tiger abundance and other demographic parameters to assess the species status over space and time. This is important because of the immense pressures on
tiger populations and habitats. In addition, the monitoring exercise also provides valuable information on the movement of dispersing tigers and has helped us identify existing and potential corridors in need of conservation actions. This has furthered understanding of tiger occurrence and behavior
in human-dominated landscapes and enabled management of human-wildlife conflict in corridors and sustained engagement with multiple stakeholder groups.


What was WWF’s role?

WWF India’s biologists worked with the NTCA and State Forest Departments in the tiger monitoring conducted in WWF’s priority tiger recovery sites and beyond. The team also conducted several capacity building workshops for state forest department field staff on the methods of conducting sign surveys, deploying camera traps, and data management.


We’ve come a long way since counting pugmarks. Could you take us through some of the technological innovations in wildlife monitoring that were used in this survey?

Primary field data was recorded digitally using mobile phone applications like M-STrIPES (Monitoring System for Tigers
- Intensive Protection and Ecological Status), which uses GPS to geotag photo-evidence. Technological tools such as CaTRAT (Camera Trap data Repository and Analysis Tool) which automatically segregates camera trap photographs of species, was also used. Similarly, Program ExtractCompare6 fingerprints tigers based on their stripe patterns enabling us to count the number of individual tigers (> 1-year-old). In areas where tigers occur in very low densities, information on tiger abundance is assessed through individual identification from DNA derived from scat.


What are some of the greatest challenges in species monitoring?

Given that there is great heterogeneity in the distribution and density of tigers, it is necessary to sample habitats spanning expansive landscapes. This can be immensely logistically

challenging and resource intensive, and especially difficult in areas where tigers occur at low densities. The management
of vast quantities of data – including the identification of individual tigers from many thousands of camera trap images – is also a daunting and labour-intensive task, even when aided by technology. Finally, the monitoring of unmarked species (prey species in particular) is a key challenge because camera trap data on prey species cannot be used to reliably assess population parameters.


Is WWF doing anything to make wildlife monitoring more affordable and effective in the future?

WWF is working on developing a range of population, management and habitat indicators that can be used to assess progress towards tiger recovery across a range of scenarios, including when information on animal abundance is sparse. We are also working with the Tigers Alive Initiative to develop methods to efficiently assess prey populations from camera trap and sign survey data. We have also co- designed and are supporting the development of a low-cost camera trap with rechargeable batteries. Once these are ready, we will seek permission from NTCA and State Forest Departments for using in the field.


Rapid urbanisation, land-use, mining and linear infrastructure and poaching all pose a great threat to India’s tiger population. How is WWF addressing these challenges?

In order to make linear infrastructure projects such as roads and railways tiger-friendly, WWF India engages closely with policymakers, planners and executing agencies to advocate on avoidance of critical biodiversity areas to enable safe passage of wildlife. The ecological restoration of abandoned mining sites and engaging in siting new mines and mining infrastructure in critical wildlife corridors has also emerged as a key area of work in recent years, primarily in the Central India Landscape.

We also have a strong programme to encourage the involvement of local communities living around tiger
habitats in conservation through a multi-pronged approach emphasising community-based natural resource management including biodiversity conservation, promotion of sustainable livelihood activities and managing human-wildlife conflict.

WWF India is also actively engaging with regional and city planners to explore how the expansion of cities in and around tiger landscapes can be better planned and managed in a manner that conserves critical forest areas in the vicinity.

Bengal Tiger (Panthera tigris tigris) female 'Noor T39' with cubs in water. Ranthambore National Park, India. © naturepl.com _ Andy Rouse - WWF

Find out more about the work being done to double global tiger numbers in our 2019 Annual Report, out now!



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