The fading tiger’s future brightens a bit in analysis led by Minnesota researcher

Photo by Suzanne Palminteri/World Resources Institute
A tiger in India’s Bandhavgarh National Park

Satellite data from the world’s remnant tiger habitats suggests that the big cat’s slide toward extinction can be slowed and its remaining numbers doubled in the next seven years, a new research paper reports.

And the Minnesota scientist who led the analysis says he’s optimistic that the doubling goal, though ambitious, will actually be achieved.

Depending on whose estimate you use, the world’s tiger population has fallen to somewhere between 3,000 and 3,500 animals. That’s less than half what it was as recently as 1998, according to the International Union for Conservation of Nature and Natural Resources (IUCN).

The biggest driver of that decline has been habitat loss. A natural range that once reached to Turkey and eastern Europe has shrunk eastward to parts of 13 Asian nations, according to the University of Minnesota’s Anup Joshi, who specializes in using satellite images and computerized databases to study problems of just this kind.

The tiger’s home territory, Joshi says, is now scattered among India, China, eastern Russia, Bhutan, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Nepal, Sumatra, Thailand and Vietnam (the IUCN adds Bangladesh).

This political fragmentation has worked against coordinated conservation and recovery efforts until recently. But because of the tiger’s iconic status in multiple cultures, and thanks to the promise of significant financial support from the World Bank, a multinational effort of sorts is under way now.

The International Tiger Forum, which met in Russia’s St. Petersburg toward the end of 2010, came up with a Global Tiger Recovery Program focused on a bold first goal known in conservation biology circles as Tx2 – a doubling of the world’s tiger population by 2022. But could it be done?

Joshi thinks so. In a paper published last week in Science Advances, he reports the discovery that losses of forested in the world’s most important tiger territories has been “far less than was anticipated”  over the last 14 years

Losses below expectations

In 76 landscapes that have long been identified by IUCN as important for tiger conservation and recovery, forest losses over the last 14 years were in the range of 7.7 percent.  And in the 29 landscapes designated as critical by the Tx2 effort, the declines were even less – about 6.9 percent.

Most of the latter losses took place in 10 of the 29 areas; the rest showed little change at all. And in the three largest landscapes of the set, the losses were less than 4 percent.

This is all the more remarkable considering that the Tx2 territories are surrounded by settled areas “supporting the highest rural population densities on earth,” Joshi wrote, whose forests are ripe for harvest and/or conversion to palm oil plantations.

Because tigers require large, unbroken swaths of habitat, mere acreage isn’t sufficient – the territory has to be contiguous or connected, and fragmentation of the remaining habitat is the second big pressure on tigers after outright loss.

The third, he explained to me in an interview on Monday, is poaching – market-minded killing that adds to and amplifies the development-driven changes that have pushed tigers to the corners of their former world.

Once a “generalist” species in terms of viable terrain, the tiger has become a woodland dweller by necessity as people turned treeless terrain into cropland and settlements, not incidentally killing off a lot of tigers to protect their livestock and themselves.

That kind of pre-emptive killing is no longer a significant pressure on tigers, Joshi explained, and both sport hunting and the trade in trophy items like hides has declined under various protection programs.

A source for Chinese medicine

But tigers remain in high demand as a source for Chinese traditional medicines, and everything from bones to glands to teeth to whiskers can be made into some sort of strength-building remedy.

Small or powdered tiger parts are easier to smuggle than whole hides, and lucrative. “In Cambodia or Thailand, Nepal, India, a poacher might earn a year’s income by poaching one tiger,” he said – which makes poachers highly motivated and enforcement both difficult and corruptible.

In his own home country of Nepal, he said, poaching in and around Chitwan National Park was stopped only after the army was assigned to the task, and the army was reassigned in response to citizen pressures motivated by threatened tourism revenues.

Just as in the U.S., effective habitat conservation for large carnivores like the tiger relies heavily on keeping habitat essentially roadless.

Courtesy of Anup Joshi
Forest losses (highlighted in pink) in one of Sumatra’s tiger landscapes where losses were greatest from 2000 to 2014. The map also shows the relative success of protecting tiger habitat within the Bukit Tigapuluh National Park.

“Roads are a mortality magnet for tigers,” Joshi likes to say, and he isn’t talking about the risk of being killed by vehicles (although, in one well-known incident, a tiger crossing a new highway in Nepal was killed by a speeding truck). The problem is that roads open tiger habitat to human settlement and, of course, expose the tigers to more poaching.

An interesting aspect of the Joshi team’s paper is that that underlying data – 14 years’ worth of satellite imaging, at very high resolution – “is actually available to anyone with a computer and an internet connection.”

This is because of a project called Global Forest Watch, a partnership uniting the World Resources Institute with Google, the U.N. Environment Programme, the Center for Global Development and three dozen other partners.

The idea is to use NASA-supplied satellite data at a very high resolution – 500 meters – to keep tabs on forest cover around the world, sending out updates on significant losses every 16 days and special alerts even more often than that. And the results are viewable in Google Earth.

“This is a statistic that blows my mind every time I read it,” Joshi told me, “but putting this tool together took something like a million CPU hours. Using Google’s cloud computing, with something like 10,000 computers sharing in the work, it was all done in a matter of days, maybe a week.”

‘I’m pretty optimistic’

Joshi said the new paper is just the beginning of a continuing effort to monitor tiger habitat, via Global Forest Watch, for future changes that can guide policy on the ground. And not everything that’s happening on the ground is about habitat loss.

One thing we wanted to bring out in the paper is some positive work that’s going on – like community antipoaching efforts that are starting as communities begin to understand the benefits of protecting tigers. Tourism can be huge – people will go to places to see tigers.

In the Terai Arc Landscape, on the border of Nepal and India, that links different tiger-protected areas in the Himalayan foothills, there’s an effort to restore and manage corridors with the participation of local communities.

Here we saw habitat coming back, and tigers coming back, and as a result India and Nepal are both reporting gains in tiger populations [of 61 percent and 31 percent, respectively]. So I’m pretty optimistic, yes, I am.

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The full paper, “Tracking changes and preventing loss in critical tiger habitat,” can be read or downloaded here without charge.

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