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 News :. Camera Traps Expose Tiger
Braving falling trees, snakes, leeches, and other dangers, intrepid researchers have used camera traps to produce the first reliable count of Malaysian tigers. The study is one of few detailed ecological studies attempted for Southeast Asian tigers-perhaps the least-known of all tiger populations.

Conservation scientist Kae Kawanishi, formerly of the University of Florida in Gainesville, and a team of local assistants, spent three years arranging and maintaining automatic cameras that captured the images they required.

The team had the tigers of West Malaysia's Taman Negara National Park in their sights. The 4,350-square-kilometer (1,677-square-mile) park is among Southeast Asia's largest reserves.

Difficult to Count

Camera traps are a new line of attack for biologists working against the odds to count one of the most awe-inspiring and elusive carnivores. Kawanishi, who completed the project for her doctorate last year, is now submitting her findings for publication in research journals.

Despite the relatively pricey machinery (the cameras cost U.S. $450 or more apiece), the method may be widely applicable. "It's been tried successfully in at least India and Sumatra, and theoretically could be used across the species' range," said Kawanishi, who is now with the Malaysian Department of Wildlife and National Parks Division of Research and Conservation in Kuala Lumpur. "The same innovative method is being used to estimate the population size of jaguars in Latin America and amur leopards in Russia," she said.

Basic information on ecology, distribution, and population size are essential for conservation of the world's remaining tigers. Estimates suggest 5,000 to 7,000 remain, said Kawanishi. "But who knows, it's not based on good science." She does have more confidence in estimates that Panthera tigris has lost more than 95 percent of its original range during the last few centuries-the range now spans 160 isolated forests in 12 countries from Siberia to Sumatra.

Traditional counting methods include the track mark counting method used extensively in India, as well as radio-collar tracking methods. The former method requires wildlife workers to find, compare and count tiger paw prints. However, a recent study from some of the world's top tiger workers, published in the journal Animal Conservation argues that this method has produced inaccurate and unreliable data and led to bad conservation practices. Neither method is suited to rainforest where vegetation smothers radio signals, and tracks are difficult to locate or disappear rapidly.

Trigger Happy

To get the required basic data for conservation planning, between 1998 and 2001 Kawanishi and her team set up 150 cameras across three different sites, each spanning 200 square kilometers (75 square miles).

Tigers have distinctive stripes, but to ensure identification both flanks must be photographed. So, camera traps were used: with several cameras facing one another along much-trafficked wildlife trails. Passing tigers, rhinos, tapirs, deer and other animals triggered the shutter by tripping infrared sensors.

Trapping images has been proved a more reliable method in India than the traditional track mark count. By examining how frequently an animal is recaptured, it's possible to use well-established population models to estimate total population sizes.

"This is a non-invasive way of tracking tiger numbers that is being used more and more widely," commented John Seidensticker, researcher at the Smithsonian's National Zoo in Washington, D.C., and chairman of the Save the Tiger Fund Council. "Camera traps make all the difference in the world because you can identify individual tigers," he said.

Setting up the machinery was a logistical challenge, taking up to three months in each of the three sites. Except for one 13-kilometer (8-mile) stretch, Taman Negara has no roads whatsoever, making it one of the world's least accessible national parks.

Others hazards compounded the difficult terrain and torturously thick vegetation. Taman Negara's huge trees cling precariously to thin earth, and frequently collapse. "We never came close to one, but we could hear them almost daily. It sounds like a big thunderclap, with vibration through the air and ground," said Kawanishi.

Worthwhile Conservation

Despite the perilous nature of the work, the efforts were worthwhile. Over more than 14,000 nights of image taking, Kawanishi was able to collect 35 photographic captures of tigers (61 images) amongst more than 4,500 single wildlife images. Other animals photographed included elephants, sun bears, porcupines, clouded leopards, wild dogs, and panthers.

Analysis suggested that Taman Negara is able to support around 91 (between 70 and 112) adult tigers and cubs. Perhaps as importantly, the images and years of trekking in the jungle provided no evidence that poaching or exploitation are significant threats: Anyone convicted of killing a tiger risks a U.S. $4,000 fine and five years' imprisonment.

"The study shows that tiger numbers there are stable, which means that conservation efforts have been successful," commented the National Zoo's Seidensticker.

The population is secure for at least 100 years predicts Kawanishi, as long as it remains free of poaching. "When you compare that result with the threat to tiger populations in similar sized parks [elsewhere], Taman Negara is unique and superb," she said.

Kawanishi's study was mainly financed by the Save the Tiger Fund, a project of the U.S. National Fish and Wildlife Foundation and ExxonMobil. The fund started in 1995 and has supported 177 conservation projects with U.S. $9.7 million. Other study funders included the Disney Wildlife Conservation Fund, the University of Florida, the WWF in Japan, the U.K. and the Netherlands, and 21st Century Tiger, a conservation project at London Zoo.
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