Nagarahole National Park, India–Tigers do not roar. Lions roar. In the complete night of the Indian jungle, a tiger resonates. The very forest vibrates when it speaks. Yes, I understand the physics: mice squeak, cats purr, and so on up the scale as body size increases. Pitch tells me how large is the animal.
By extrapolation, tigers must be huge, so deep is the rising then the falling of their announcement. They are completely terrifying — they must be monsters of impossible proportions. Perhaps the resonance is partly my physiological reaction.
As I walk back from eating dinner through the forest clearing to the guest house, I could be dinner. I understand these things too intellectually — I wrote the book on food chains: most living things eat and are eaten.
Gaur are wild cattle, powerfully muscular under their sleek coats. (How can they be genetically related to the small cattle of India’s villages, their ribs protruding, their heads held low, cowed by their herders?) Gaur, hidden by the jungle in the day, stroll silently into the clearings as dusk falls, very wild and very threatening, as they appear suddenly in the lights of our 4×4. The bull is huge, his horns no ornament, his harem his alone because he’s gored the only slightly less impressive opposition.
The tiger is not after me. Gaur are tiger food. While my mind tells me that I’m unlikely to be the tiger’s supper, the hairs on my neck don’t believe it as I hear its roar.
Providing my dinner — and my tiger guide — is Ullas Karanth, India’s premier tiger ecologist.
He has just let out a roar of his own.
Quite simply, Dr. Karanth has examined the latest data on how many tigers there are in India. Those numbers, he tells us, are simply inadequate. We need much better estimates — with modern techniques, geographically explicit, and done annually, if we are to stem this big cat’s decline.
I’m no tiger expert, but as a member of National Geographic’s Big Cats Initiative, what he says about tigers worries me deeply. We lack accurate counts of all the big cats. Without them, we cannot be certain how well — or how badly — our conservation efforts are faring.
Half the world’s tigers are in India. This is a very significant problem.
Ullas’s e-mail to me is in response to the national tiger estimation exercise conducted in 2010. It was released today, March 28. It reports an increase in adult tiger numbers to 1636 (1706 including the tigers believed to be in the Sunderbans, a conservation area not previously included in the tiger count). That’s up from the previous estimate of 1411 tigers in 2007 — an increase of 16 percent over 4 years. Superficially, this is encouraging and suggests that the previous decline of tigers has stopped.
Ullas is critical. He writes:
“Full details are not yet available on how these tiger numbers were obtained. It’s just not possible to give an expert opinion on them. Moreover, since various threats faced by tigers have not diminished in last four years, it is difficult to explain the claimed reversal of the decline of tigers.”
Tigers are now much reduced in both numbers and range. Some 90 percent of India’s tigers are concentrated in 10 percent of all tiger habitat. There are 40 or so ‘source populations’ — places where tigers breed and from which tigers can disperse to other areas.
“These places are under grave threat and need to be ecologically monitored annually, using intensive camera trapping. Monitoring of tracks by Forest Guards is not a substitute for such reliable monitoring using camera traps or DNA sampling as has already been proven earlier in places where tigers vanished even as guards did similar patrol-based monitoring. “
Reading Tigers Like a Bar Code
There’s a point in his tiger seminars that I always enjoy. “How do you count tigers?” He asks. There’s a dramatic pause. “You read them like a bar code.”
The pattern of stripes on a tiger’s side is unique. Set up a pair of cameras — one needs to read both sides — and when a tiger trips the camera the pair of photographs provides a unique ID. Ullas revolutionized tiger counting this way. The fur flew when he pointed out that numbers were far smaller than those previously expected.
Camera trapping has come a long way in a decade, with the technology being faster, better, and cheaper. DNA sampling — which can be done from hairs or scat — also identifies individuals and promises to do so cheaply. So why is this not being done?
Ullas’s criticism is stinging.
“To me the most serious flaw in the present government effort is the basic futility of trying to generate all-India level tiger counts once in 4 years, even while ignoring critical task of intensively monitoring key source populations year after year,” he writes.
“The time has now come to switch from these once in four year national estimation and focus intensive camera trap or DNA monitoring of tiger source populations so that we can track the fate of individual tigers, and estimate survival and recruitment rates to gauge how each of these populations is faring. If we do not shift to such focused, intensive monitoring approaches, we are at serious risk of losing more and more key populations even while we celebrate supposed ‘increases’ from these national counts.
“It is well known that half the tiger reserves lost most of their tigers in the past decades despite these national counts!”
Can this be done? I asked Ullas.
“For several years Centre for Wildlife Studies has monitored tigers rigorously in Karnataka State over an area that holds about 15 percent of the country’s tigers. We camera trap a 3000 sq km area, every year, photographing more than 100 tigers in a population of about 250.”
“And, what do your data show,” I continued.
“On the basis of these data we believe that the tiger population in Karnataka is holding out, and even increasing in some areas like Bhadra and Kudremukh because of good work by government and NGOs.
“We believe that similar intensive monitoring of all key source populations can be easily done to generate similarly useful results across the country.
“However, to achieve such progress, government must give up its present monopoly over tiger monitoring and bring in outside expertise and resources in order to ensure greater reliability, transparency and credibility in monitoring the fate of our national animal.”
A few years ago, in a habitat far, far away from the jungle of India, I was at a cocktail party in Washington, D.C. A large conservation organization had just issued a report on the numbers of another, famously charismatic large mammal.
I found myself talking to the head of that program and so asked about the numbers and the methods. She fobbed me off, so I probed some more. In short order, she slammed down her glass, the red wine spilling over me, and stormed off, offended by my temerity.
Counting endangered plants and animals is often tedious and sometimes dangerous. Worse, the results are often not encouraging. Can one raise money from donors unless one claims success? What is certain is that without reliable, transparent and credible numbers, we have no idea whether we are saving nature.
Professor Stuart L. Pimm is a conservation biologist at Duke University, North Carolina. A former member of the National Geographic Committee for Research and Exploration, Pimm is the author of dozens of books and research papers, including the book “The World According to Pimm: A Scientist Audits the Earth.”