Qamar Qureshi: More than a numbers game
How many tigers are there in India, anyway?
It was an exciting time for me to study tiger conservation in India as a 2014-15 Fulbright Scholar, because my visit coincided with the production of the 2014 Status of Tigers in India report. Produced by the National Tiger Conservation Authority in collaboration with the Wildlife Institute of India, state forest departments and Indian conservation non-profits, the report is an analysis of data gathered from India’s countrywide, quadrennial census of “tigers, co-predators, prey and their habitat.” The report gives comprehensive information, not only of the numbers of animals inside and outside the more than 40 tiger reserve protected areas and the surrounding corridors, but also of the quality of their habitat, such as whether a forest is degraded, the proximity of human settlements, presence of adjoining corridors, and availability of water sources and canopy cover.
In my travels across the country, debate and conversation were at an all time high with people I engaged about the census, from institute researchers and non-profit affiliated conservationists to chief conservators and wildlife wardens. There was a heightened, palpable urgency on the campus of the Wildlife Institute of India where I was affiliated, as students and faculty worked diligently throughout the months preparing data for this important report. Methods used in the field to gather data, which included camera traps, ground surveys and remote sensing approaches, were approved by the Tiger Task Force with input from a team of national and international collaborators, from statisticians to biologists.
The 2014 Status of Tigers report, released in January 2015, found that 2,226 tigers exist in India, an estimate that is up by approximately 30% from 2010. The report attributes the rise in tiger numbers to changes in wildlife management, policy, legislation, and implementation of a conservation plan for Indian tiger reserves. The increase is good news for tiger habitat and the conservation community that has worked hard to improve the situation of tigers.
I met with senior biologist Qamar Qureshi of the Wildlife Institute of India to discuss the scope of the census effort and methods used to count tigers. Qureshi brings decades of experience to the field of wildlife conservation, with specialization in endangered species, large carnivores, quantitative ecology and geographical information systems. He and colleague Dr. Yadvendradev Jhala, a prominent tiger expert at WII who was my faculty advisor during my Fulbright term, are among the leading researchers behind the 2014 report.
Qureshi’s involvement in national and international tiger monitoring efforts began in the early 2000s. Together with a team of scientists including Jhala and Dr. Rajesh Gopal, Secretary General of the Global Tiger Forum and former Member Secretary of the National Tiger Conservation Authority, Qureshi developed the All India Tiger Monitoring project, a precursor to the current census that improved on older census methods by utilizing sign surveys, GIS and camera traps. The project was adopted countrywide in 2006 after tigers were found to be extinct at Sariska Tiger Reserve in 2005. Sariska, an older Indian park located in the state of Rajasthan, was created in the 1950’s and became a reserve in 1978. The Sariska tragedy was the canary in the coal mine that awoke India to a need to devise even more rigorous strategies to protect its tigers.
Qureshi currently directs the Information Technology, Remote Sensing and Geographic Information System facility at WII. The lab is at the heart of the monitoring effort and gives information about the ecology of carnivores both in and outside protected areas as well as the status of human encroachment on habitat, such as village expansion, and how animals are dispersing across landscapes. Information gathered is used to affect policy and management intervention of large carnivores, including the tiger.
In a discussion of the different methods used to count tigers, Qureshi explained that camera traps yield the best information about animal presence in forests. Approximately 70-90% of Indian tigers are concentrated in 10-30% of the forest, and camera traps have recorded a lion’s share of their numbers. But how to count the 10-30% of tigers in the remaining forest? For this he said you need index calibration, a method that factors the number of tiger signs, like scat and pugmarks, and also signs of other species found and counted across many gridded, sampled research areas. Qureshi said that Index calibration yields robust, accurate results for counting tigers across large regions. Scientists use the collected, real density data to create a predictive model that is then used to determine tiger abundance in terrain where humans cannot easily go and where camera traps are difficult or not possible to install.
Qureshi contrasted the index calibration method to the occupancy model, another method used to supplement data in the 2014 report. Occupancy examines the presence and also the absence of animal signs in an area and represents the information as “0” or “1.” The presence of tiger signs becomes “1,” and the absence becomes “0.” The density of these signs is not evaluated. In other words, regardless of whether there are five or 100 signs, the density would still be 1. Qureshi said that the occupancy model is appropriate for predicting the geographical range of tigers, but that it cannot be used to estimate actual tiger numbers.
“For that you need index calibration. There is no better way to predict the data,” Qureshi said.
More than a numbers game, Qureshi emphasized that calibration analysis reveals large-scale information about the overall health of forest ecosystems. As an umbrella species, when the tiger does well, it reflects well on flora and other fauna in tiger bearing forests. Declining numbers of tigers or other species alert scientists to investigate possible causes. The census highlights the web of relationships, not just tigers. In this regard he said the calibration method, used together with camera traps, represents a paradigm shift from the older Deccan model that was based only on total tiger count.
Qureshi concluded by saying that the methods scientists choose to adopt for counting tigers change over time, and that he and his colleagues at WII are open to exploring new approaches when credible ones become available in order to evolve science — that what matters is to adopt the right ones.
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