On 10 April 2016, WWF and the Global Tiger Forum announced that the world’s tiger population had finally increased “after several decades of constant decline”.
From “as few as 3,200” tigers in 2010, tiger numbers have risen to 3,890 tigers now, they said in a statement. For a species struggling to survive, these figures look promising.
But tiger numbers may not have “truly” increased, four tiger experts warn. The experts — Ullas Karanth and Dale Miquelle of Wildlife Conservation Society, John Goodrich of Panthera, and Arjun Gopalaswamy of the University of Oxford — have called WWF’s report, and its implications, “scientifically unconvincing”.
Tigers are elusive, and counting them is hard. Over the years, scientists have developed better monitoring methodologies that allow conservationists to miss fewer tigers in the field, and estimate tiger numbers more accurately.
An increase in tiger numbers could indicate that tiger conservation measures are working. But it could also mean that better tiger monitoring techniques have allowed more individual tigers to be counted.
“The latest report of an increase in the world’s global tiger population is based on the compilation of greater and better data due to these improved monitoring efforts, rather than valid, scientific evidence of tiger population increases,” Goodrich said in a statement.
The increase in tiger numbers could also be a result of using flawed survey techniques that may over-estimate and inflate tiger numbers. One problem, according to the experts, is that tiger numbers reported by the various tiger range countries tend to be largely unreliable.
Survey methodologies used to estimate tiger numbers are not uniform across all tiger range countries. While some countries employ rigorous camera trap or DNA surveys to estimate size of tiger populations, others use unreliable and unscientific methods such as counting tiger pugmarks or droppings. Sometimes, methodologies vary in different parts of the same country, resulting in widely varying estimates of tiger numbers.
“Using flawed survey methodologies can lead to incorrect conclusions, an illusion of…