Tiger Census in India

 India currently harbors almost 75% of the world’s wild tiger population. The Ministry of Environment, Forest and Climate Change launches the detailed report of the All India Tiger Estimation on the occasion of Global Tiger Day  ie. 29th July. 

Tiger census

Lions and tigers were traditionally tracked by professional shikaris from their pugmarks for shikar. After the first lion census, based on pugmark count, by Wynter-Blyth and Dharmakumarsinh (1950), Saroj Raj Choudhury, a forest officer from Odisha modified the approach for counting tigers (Choudhury 1970). Subsequently, several forest officials advocated and improvised on the pugmark method for tiger census (Panwar 1980, Sawarkar 1987, Singh 1999, Rishi 2010). Karanth et al. (2003) brought out several deficiencies of the pugmark census in light of modern science dealing with animal abundance estimation (Williams et al. 2002).

But it was only after the Sariska debacle in 2004-05 (and subsequently in Panna in 2007-08), where despite total local extinction of tigers due to poaching, official records showed presence of substantial tigers based on the pugmark census. This disaster and its extensive media coverage prompted the Prime Minister of India to appoint the Tiger Task Force (TTF) with a mandate to develop a strategy for tiger conservation in India. Besides recommending the creation of the National Tiger Conservation Authority (NTCA), and amendment of the Wildlife (Protection) Act 1972, the TTF also suggested a country wide monitoring of tigers and their ecosystems based on modern scientific protocols developed by the Wildlife Institute of India in collaboration with Project Tiger Directorate and Madhya Pradesh Forest Department (Jhala et al. 2005).

NTCA in collaboration with the State Forest Departments, Conservation NGO's and coordinated by the Wildlife Institute of India (WII), has conducted a National assessment for the "Status of Tigers, Co-predators, Prey and their Habitat" every four years since then. The first status assessment of 2006 was peer reviewed by international carnivore experts and the IUCN. The methodology (vide Methodology Chapter of the current report for more detail) used for these 2 assessments was standardized after a pilot survey conducted in about 20,000 km area of Satpura-Maikal landscape of Central India.

Tiger statistics in India

The parameters used to assess the Indian tiger population status are abundance, i.e., the number of individuals in a population occupying the same space at the same time, and density i.e. abundance scaled by area and spatial distribution.

Fifth estimation

The fifth cycle of All India Tiger Estimation (2022) covered forested habitats in 20 states of India. A foot survey of 6,41,449 km was done for carnivore signs and prey abundance estimation (Table 1). In these forests, 3,24,003 habitat plots were sampled for vegetation, human impacts and ungulate dung. Camera traps were deployed at 32,588 locations, resulted in 4,70,81,881 photographs of which 97,399 were of tigers. The total effort invested in the survey was over 6,41,102 man-days. We believe that this is the world’s largest effort invested in any wildlife survey till date, on all of the above counts.

A total of 3,080 individual tigers (> 1 year of age) were photo-captured which is larger than the ones captured in 2018. The minimum population estimate is 3,167 individuals. The tiger occupancy has increased from 1758 cells of 100 km²  in 2018 to 1792 in 2022. The unique tigers photographed in 2022 is 3080, while in 2018 there were 2461 unique tigers captured. The minimum estimated population is 3167.

• Population increase is substantial in Shivalik & Gangetic flood plain which is followed by Central India, North Eastern Hills and Brahmaputra flood plains and Sundarbans while Western Ghats population showed decline with major populations being stable.
• Central India and the Shivalik Hills and Gangetic Plains witnessed a notable increases in tiger population, particularly in the states of Madhya Pradesh, Uttarakhand, and Maharashtra.
• However, certain regions, such as the Western Ghats, experienced localized declines, necessitating targeted monitoring and conservation efforts.
• Some states, including Mizoram, Nagaland, Jharkhand, Goa, Chhattisgarh, and Arunachal Pradesh, have reported disquieting trends with small tiger populations.
• The largest tiger population of 785 is in Madhya Pradesh, followed by Karnataka (563) & Uttarakhand (560), and Maharashtra (444).
• The tiger abundance within the Tiger Reserve is highest in Corbett (260), followed by Bandipur (150), Nagarhole (141), Bandhavgarh (135), Dudhwa (135), Mudumalai(114), Kanha (105), Kaziranga (104), Sundarbans (100), Tadoba (97), Sathyamangalam (85), and Pench-MP (77).
• Various tiger reserves have shown remarkable growth, while others face challenges. Approximately 35% of the tiger reserves urgently require enhanced protection measures, habitat restoration, ungulate augmentation, and subsequent tiger reintroduction.
• To preserve ecological integrity, there is need to strongly continue eco-friendly development agenda, minimize mining impacts, and rehabilitate mining sites. Additionally, fortifying protected area management, intensifying anti-poaching measures, employing scientific thinking and technology-driven data collection, and addressing human-wildlife conflict are vital steps to protect the country's tiger populations.
• The involvement of various stakeholders, such as governments, NGOs, local communities, and businesses, is crucial. Strategies like increased patrolling, monitoring, and law enforcement, focus on “Other Effective Area-based Conservation Measures (OECM)” along with promoting eco-tourism and sustainable livelihoods for local communities, can help achieve this goal. 

To access the complete report, click here. 

Fourth assessement

The fourth cycle of the assessment was undertaken in 2018 and 2019 using the best available science, technology and analytical tools.

In this cycle, recording of primary field data digitally, through mobile phone application M-STrIPES (Monitoring system for tigers - intensive protection and ecological status), that uses GPS to geotag photo-evidences and survey information, made this exercise more accurate. Further, it involved the development of innovative technology like automated segregation of camera trap photographs to species using artificial intelligence and neural network models (software CaTRATCamera Trap data Repository and Analysis Tool). Program ExtractCompare (Hiby et al. 2009) that fingerprints tigers from their stripe patterns was used to count the number of individual tigers.

Like the previous cycles, this time also the country was divided in five tiger occupied landscape complexes having unique geographical features and tiger populations:

• Central Indian and Eastern Ghats landscape extends across the states of Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, Maharashtra, Telangana, Andhra Pradesh, and Odisha.
• Western Ghats landscape extends across the states of Karnataka, Tamil Nadu, Goa, and Kerala.
• Shivalik and the Gangetic Plains landscape extends across the states of Uttarakhand, Uttar Pradesh and Bihar.
• North Eastern Hills and Brahmaputra Flood Plains landscape extends across parts of Northern West Bengal, Assam, Arunachal Pradesh, Mizoram, Nagaland.
• Sundarban landscape comprises of the mangrove forests of southern part of West Bengal and extends into Bangladesh.

This report assesses the status of tigers in terms of spatial occupancy and density of individual populations across India. The report covers the following

• Summary report
• Comparison of information obtained from the earlier three surveys (2006, 2010, and 2014) with data obtained from the 2018-19 survey to estimate population trends at country and landscape scales, patch colonization and extinction rates along with information on likely factors responsible for changes in tiger status at the fine spatial 2 resolution of 100 km .
• The status of habitat corridors connecting major tiger populations and highlights vulnerable areas that require conservation attention for each landscape.
• Information on major carnivores and ungulates regarding their distribution and relative abundance.
• Individual sites that were assessed by camera traps and some that were assessed by line transects, report the details of tiger densities and prey densities.
• Photographs of all individual tigers that were recorded across India (2018-19) as an appendix to the report.

Results at a glance

• The overall tiger population in India was estimated at (SE range 2,603 to 3,346)
• Tigers were observed to be increasing at a rate of per annum in India when consistently 6% sampled areas were compared from 2006 to 2018
• The magnitude of anthropogenic disturbances within Tiger Reserves and tiger occupied areas include the following
  • Livestock grazing was high in Mukundara, Udanti-Sitanadi, Panna, Buxa, Sariska, Sanjay-Dubri, Achanakmar, Dudhwa and Rajaji Tiger Reserves.
  • While free ranging dogs abounded in Udanti-Sitanadi, Kawal, NSTR, Amrabad, Sariska and Kali Tiger Reserves 
  • Decline and lack of improvement in the status of Udanti-Sitanadi, Achanakmar, Amrabad, Palamu, NSTR and Dampa Tiger Reserves can be correlated with a high disturbance regime and poaching.
  • Udanti-Sitanadi was on top of the list of Tiger Reserves for the disturbance indices, and major investments are required in protection.
  • From amongst tiger reserves that had good spatial camera trap coverage, human impacts were recorded to be low (good protection) for
    Sundarban, Orang, Kalakad Mundanthurai, Periyar, Corbett, Manas, Kaziranga and Bandipur Tiger Reserves. 
• Feral dogs were detected in most tiger reserves. Dogs are a threat to both ungulates (which they hunt) and to carnivores, since they carry infectious diseases like rabies, parvovirus, and distemper. 
• Incentivized voluntary relocation of tribal communities from the core of NSTR and Amrabad TRs should be a priority.

To access the complete report, click here. 

Second and third assessments

The second and third assessments were carried out in 2010 and 2014 which estimated India's tiger population to have increased to 1,706 (1,520 to 1,909) and 2,226 (1,945 to 2,491) respectively (Jhala et al. 2011, 2015). These 2010 and 2014 assessments included the Sundarban tigers which accounted for 70 (64-90) and 76 (62-96) tigers.

First assessment of tigers in India

The first countrywide assessment was done in 2006 and it estimated India's tiger population to be 1,411 (SE range 1,165 to 1,675). Before this scientifically objective assessment, the official tiger number in India was estimated at 3,500 tigers. The 2006 assessment was spatially explicit and determined the extent and size of individual tiger populations and the status of habitat connectivity between these populations for the first time at a national scale (Jhala et al. 2008). During the 2006 exercise the Sundarban landscape was not assessed, as at that time, the protocol for sampling this hostile and unique tiger habitat had not been developed.

Source : Project Tiger