India's 2018 Tiger Census Sets Guinness Record For Being World's Largest Camera Trap Wildlife Survey

The results of the fourth cycle of the All India Tiger Estimation 2018 were declared to the nation on Global Tiger Day last year by Prime Minister Narendra Modi. For the survey, camera traps were placed at 26,838 locations across 141 different sites. It had estimated 2,967 tigers or 75 per cent of the global tiger population in India, compared to 2,226 in 2014.

"The All India Tiger Estimation is now in the Guinness World Records for being the largest camera trap wildlife survey, a great moment indeed and a shining example of Aatmanirbhar Bharat," Environment Minister Prakash Javadekar tweeted on Saturday, June 11.

The Minister added that under the leadership of the Prime Minister, India fulfilled its resolve to double tigers numbers four years before the target through "Sankalp se Sidhi". He also shared a picture of the World Record citation.

How 2018 Tiger Census Survey Was Carried Out

The survey was carried out by the Indian government's National Tiger Conservation Authority (NTCA) and the Wildlife Institute of India (WII), in collaboration with state forest departments and conservation NGOs.

"The fourth iteration of the survey – conducted in 2018–19 – was the most comprehensive to date, in terms of both resource and data amassed. Camera traps (outdoor photographic devices fitted with motion sensors that start recording when an animal passes by) were placed in 26,838 locations across 141 different sites and surveyed an effective area of 121,337 square kilometres (46,848 square miles)," the Guinness World Records website said.

"In total, the camera traps captured 34,858,623 photographs of wildlife (76,651 of which were tigers and 51,777 were leopards; the remainder were other native fauna). From these photographs, 2,461 individual tigers (excluding cubs) were identified using stripe-pattern-recognition software (Jhala et al., 2020)," it added.

The website further stated that in addition to "unprecedented camera trap usage", the survey also conducted extensive foot surveys covering 522,996 km of trails and sampled 317,958 habitat plots for vegetation and prey dung.

"It's estimated that the total area of forest studied was 381,200 km2 (147,181 sq mi) and cumulatively the collection and review of data equated to some 620,795 labour-days," it said.

The survey was carried out over three phases and the various datasets were combined to be extrapolated via statistical computation, which informed the final results published in the survey report.

"A positive outcome of the survey was that it concluded that India's tiger population had increased by roughly one-third: from 2,226 in 2014 to 2,927 in 2018, though some have cautioned that this rise may in part reflect more comprehensive surveying as opposed to purely a population surge," the website said.

In 2018–19, the ground surveys and camera traps recorded tiger presence in 88,985 km2 (34,357 sq mi) of forests across 20 Indian states, with the majority being found in Madhya Pradesh, Karnataka and Uttarakhand. The three states alone accounted for 1,492 tigers.

It also added that other key takeaways that still need to be improved to continue tigers' comeback include improving "corridors" between isolated pockets of tiger territory, reducing poaching, and helping to build up prey numbers through habitat restoration.

"There is hardly any parallel of such a focused species oriented program like Project Tiger across the world, which started with 9 Tiger Reserves, with 50 tiger reserves currently. India has now firmly established a leadership role in tiger conservation, with its bench marking practices being looked at as a gold standard across the world," the Ministry of Environment, Forest and Climate Change(MOEFCC) said in a press release.

Academics Say Estimation Method Misleading

A scientific paper titled "How sampling-based overdispersion reveals India's tiger monitoring orthodoxy" published in the Journal Conservation Science and Practice on November 4, 2019 had questioned the veracity of the data and claimed that the methodology adopted was flawed.

The paper by Arjun M Gopalaswamy from the Indian Statistical Institute, K Ullas Karanth from the Centre for Wildlife Studies, noted tiger expert Mohan Delampady from the Indian Statistical Institute, and Nils C Stenseth from the University of Oslo had flagged photographic manipulation and mathematical flaws with the survey.

"The criticisms levelled so far have ranged from fundamental mathematical flaws, design deficiencies and manipulation of photographic data, and a total lack of transparency in data-sharing with independent scientists capable of reliably reviewing the analyses and results," a release issued by Centre for Wildlife Studies (CWS), Bengaluru, had said.

According to the authors, a major issue was the use of a survey methodology that relies extensively on models involving an 'index of tiger abundance' derived from field counts of tiger signs.

"The government surveys assume that a tight predictive relationship exists between real tiger numbers and their sign," it said.

The authors of the study had recommended a comprehensive re-analysis of India's tiger survey data and a new tiger monitoring. In addition, it also called upon the government to share the raw tiger survey data, analyses and results with the wider scientific community to ensure a safe future for wild tigers.

"The Prime Minister needs to create a bold new public-private partnership of qualified scientists and conservationists, to employ modern rigorous survey methods to generate reliable results to guide the conservation of our national animal," Karanth had said.

However, the MOEFCC had denied these criticisms.

"The Wildlife Institute of India had applied for this Guinness World Record with our (NTCA) approval soon after the results were declared by the Prime Minister. We stand by our numbers and estimation methodology. In fact, out of the estimated 2967 tigers, 2461 tigers or 83 % of them have been individually captured. If anything, the numbers are conservative," Anup Kumar Nayak, former member secretary, National Tiger Conservation Authority, who was in charge of the estimation, told Hindustan Times. Nayak retired from his post on June 30.