Tiger biologists debunk report on increase in population

“We do not find this report and its implications scientifically convincing,” said a statement issued by four tiger biologists — Dr K Ullas Karanth from Wildlife Conservation Society India, Dale Miquelle, director of Russia Program of Wildlife Conservation Society, John Goodrich of Panthera US-based Panthera Corporation and Arjun Gopalaswamy from the University of Oxford. 

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, they said.

Citing a recent World Conservation Union (IUCN) assessment which showed 40 per cent habitat loss in the last decade and a spike in poaching pressure in many regions, they said Cambodia, Vietnam, Lao PDR and China have virtually lost viable tiger populations in recent years.

A recent report by WWF and the Global Tiger Forum (GTF) had said that the number of wild tigers has been revised to 3,890 compiled from IUCN data and the latest national tiger surveys.

In the 2010 Tiger Summit in Russia, governments had agreed to achieve a goal to double wild tiger numbers by 2022. The biologists said estimates of tiger numbers for large landscapes, regions and countries currently in vogue in the global media for a number of 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,” the statement said.

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 said.

Taking these putative tiger numbers at face value, simple calculations show that doubling of the world’s tigers in ten years as hoped for in the report is not a realistic proposition, they said.