Bengaluru: Tiger biologists, including Dr K. Ullas Karanth and conservationists from across three reputed institutions of Wildlife Conservation Society – India, have taken objection to a report released on April 10 by the World Wildlife Fund (WWF) and Global Tiger Forum (GTF) that the world’s wild tiger population is on the rise and is on track for doubling in a decade. They have termed the report and its implications scientifically unconvincing.
Estimates of tiger numbers for large landscapes, regions and countries are largely derived from weak methodologies. They are sometimes based on extrapolations from tiger spoor (tracks and droppings) surveys, or spoor surveys alone. While spoor surveys can be useful for knowing where tigers occur, they are not useful for reliably counting their numbers. Translating spoor counts to tiger numbers poses several statistical problems that remain unresolved, which can lead to fundamentally flawed claims of changes in tiger numbers, they commented.
Dr K. Ullas Karanth, Director for Science Asia-Wildlife Conservation Society, along with Dale Miquelle, Director, Russia Program-Wildlife Conservation Society, John Goodrich, Senior Director, Tiger Program-Panthera, and Arjun Gopalaswamy, Research Associate, Zoology, University of Oxford, UK, stated, “Having devoted years of our lives to trying to understand and save wild tigers, we believe their conservation should be guided by the best possible science.
Using flawed survey methodologies can lead to incorrect conclusions, an illusion of success and slackening of conservation efforts, when in reality grave concern is called for. Glossing over serious methodological flaws, or weak and incomplete data to generate feel-good ‘news’ is a disservice to conservation, because tigers now occupy only 7% of their historic range.”
“A recent World Conservation Union (IUCN) assessment showed 40% habitat loss in the last decade, and a spike in poaching pressure in many regions. Cambodia, Vietnam, Lao PDR and China have virtually lost viable tiger populations in recent years. This is not a time for conservationists to take their eyes off the ball and pat each other on the back,” they stated.
“There is no doubt that wildlife managers in parts of India and even in specific reserves in South East Asia and Russia have made commendable conservation efforts, leading to recoveries in specific tiger populations. India has invested massively in recovering several tiger populations over the last four decades,” they stated.
“Such sporadic tiger recoveries should be monitored using statistically robust camera trap or DNA surveys. Rigorous scientific studies in India, Thailand and Russia demonstrate this can indeed be done. But these studies also indicate that tiger recovery rates are slow and not likely to attain levels necessary for the doubling of wild tiger numbers within a decade.”
Source populations of tigers that occur at high densities and which are likely to produce ‘surplus’ animals that can disperse and expand populations now occupy less than 10% of the remaining 1.2 million sqkm of tiger habitat. Almost 70% of wild tigers survive within these source sites.
They are recovering slowly, only in some reserves where protection has improved. Outside these source sites lie vast ‘sink landscapes’, which are continuing to lose tigers and habitat due to hunting as well as rural and developmental pressures, they said....