Though tigers still roam the pages of children’s classics such as The Jungle Book, they could soon disappear from real life. Over the past 100 years, tiger populations have plummeted 97 percent; only an estimated 3,200 survive.
The situation is urgent enough that in November 2010, scientists and heads of state from each of the 13 countries in the tiger’s range in Indonesia and southern Asia met in St. Petersburg, Russia, for the first-ever tiger summit.
Marcella Kelly, associate professor of wildlife in Virginia Tech's College of Natural Resources and Environment, said she sees the summit as an encouraging sign of cooperation among scientists and as evidence of the tiger’s precarious situation. “It’s unusual for carnivore scientists to share their data,” Kelly explains. “The magnitude of the threat is forcing everyone to work together.”
The tiger’s survival requires the scale of the solution to match that of the problem, addressing each of the threats causing the big cat’s decline. According to Sunarto, a student of Kelly’s whose work on Sumatran tigers earned him a doctorate in wildlife sciences in spring 2011, habitat loss is the tiger’s most formidable enemy. (Sunarto is from Indonesia, where people have only one name.)
As in much of the world, economic development is the root of habitat loss in Sumatra, the Indonesian island where Sunarto conducts his research. To meet global demand for acacia and oil palm products, companies are clearing tiger habitat to increase plantation acreage, reducing overall habitat area, and fragmenting what little habitat area remains. Fragmentation creates patches too small for tigers to use and isolates local populations, causing inbreeding and increasing the population's vulnerability to extirpation (extinction within a limited geographic area).
Poaching is also a threat. Because many people living near tiger populations live in extreme poverty, the lucrative black market for tiger parts can be a lifeline to survival. When economic pressure couples with innate fear of large carnivores, many people are drawn into poaching’s cycle of destruction.
Addressing these issues can be challenging because the tiger’s rarity and elusive nature makes it a difficult animal to study. Much of its ecology is still unknown. Sunarto and Kanchan Thapa of Kathmandu, Nepal, a wildlife doctoral student who conducts research work in Nepal that parallels Sunarto’s in Sumatra, said they hope their World Wildlife Fund-supported research will increase the knowledge base on which tiger conservation strategies are founded.
“Ultimately,” Sunarto said, “the goal is to learn how to restore tiger populations and habitat through better management.”
To meet this goal in Sumatra, Sunarto first needed the actual tiger population size in his study area. With help from Kelly and her expertise in camera trapping (using a hidden camera trigger by a motion detector to photograph wildlife) and analysis techniques, Sunarto now has enough data to determine that tiger densities are quite low — less than one per 100 square kilometers — and vary by forest type. Sunarto used his data to develop a series of maps that predict where tigers are most likely to live.
In the first study of its kind, Sunarto also investigated commercial plantations as potential tiger habitat. Surprisingly, he found that tigers could use plantations that met two key qualifications — dense understory cover and low human activity. Since plantations are rising as a percentage of the landscape, knowing what makes them attractive tiger habitat is crucial.
Though Thapa’s research in Nepal resembles Sunarto’s in Sumatra, Thapa incorporates a genetic sampling, a powerful new tool that allows him to track individual tigers through the landscape by analyzing DNA in tiger scat samples.
While tigers seem to be better off in Nepal than in Sumatra, both Sunarto and Thapa have concluded that the big cats are in real danger. “A lot of work is needed,” Sunarto said, “and everybody has to help.”
Sunarto and Thapa are working with the governments of their study areas to involve all stakeholders, from scientists to plantation owners, in developing policies to help ensure the tiger’s survival.
To be successful, governments and conservation groups need to go beyond preserving habitat and increasing patch connectivity to focus on education and alternative livelihood programs as well, they said. Reducing poaching and commercial land conversion will require impoverished people to give up much-needed income; they will need sustainable alternatives.
“The governments that participated in November’s tiger summit have committed to building their tiger populations over the next 10 years,” Sunarto said, “but success depends on everybody — on the companies, the governments, and us.”
See a photo gallery of tiger researchers working in both Sumatra and Nepal.
Sunarto’s tiger conservation research project was featured as the Cat Specialist Group’s conservation project of the month. Download the PDF file to read a summary of his research goals, methods, and findings.
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