Asian tiger numbers could triple if large-scale landscapes are protected

The tiger reserves of Asia could support more than 10,000 wild tigers -- three times the current number -- if they are managed as large-scale landscapes that allow for connectivity between core breeding sites, a new study from some of the world's leading conservation scientists finds. The study, published in Conservation Letters, is the first assessment of the political commitment made by all 13 tiger range countries last November to double the tiger population across Asia by 2022.

The study finds that the commitment made by tiger range states in November's historic tiger summit to double the wild tiger population is not only possible, but can be exceeded. However, it will take a global effort to ensure that core breeding reserves are maintained and connected via habitat corridors. The paper also notes that tiger landscapes can potentially "pay their way" through payment schemes for carbon storage and sequestration and other ecosystem services.

The tiger reserves of Asia could support more than 10,000 wild tigers -- three times the current number -- if they are managed as large-scale landscapes that allow for connectivity between core breeding sites, a new study finds.

"In the midst of a crisis, it's tempting to circle the wagons and only protect a limited number of core protected areas, but we can and should do better," said Dr. Eric Dinerstein, Chief Scientist at WWF-US. "We absolutely need to stop the bleeding, the poaching of tigers and their prey in core breeding areas, but we need to go much further and secure larger tiger landscapes before it is too late."

Wild tiger numbers have declined from about 100,000 in the early 1900s to as few as 3,200 today due to poaching of tigers and their prey, habitat destruction and human/tiger conflict. Most of the remaining tigers are scattered in small, isolated pockets across their range in 13 Asian countries.

"Tiger conservation is the face of biodiversity conservation and competent sustainable land-use management at the landscape level," said Dr. John Seidensticker of the Smithsonian Conservation Research Institute. "By saving the tiger we save all the plants and animals that live under the tiger's umbrella."

The authors found that the 20 priority tiger conservation landscapes with the highest probability of long-term tiger survival could support more than 10,500 tigers, including about 3,400 breeding females. They also looked at historical examples to prove that a doubling or tripling is possible using large landscapes:

• In the jungles of lowland Nepal, tiger numbers crashed during civil conflict from 2002 to 2006. However, tigers did not disappear because Nepal and India's tiger reserves are linked by forest corridors, which likely allowed for replenishment from India.
• In the Russian Far East tigers almost disappeared in the 1940s, but the region was re-populated by tigers moving in from northeastern China.
• Recently designated habitat corridors across the Sino-Russia border are helping tigers re-establish themselves in China's Changbaishan mountains, where they had disappeared in the 1990s
• In India's Nagarahole National Park, tiger numbers are "healthy and resilient" because the park is connected to other reserves in the region. Tigers number almost 300 in this large landscape of connected parks and reserves.

In contrast, the authors point to two of India's premier tiger reserves to show how lack of connectivity can preclude tiger population recovery. Tigers disappeared from Sariska and Panna tiger reserves in 2005 and 2009 due to poaching and were not able to re-colonize because these reserves are not connected to other reserves through habitat corridors. Consequently, wild tigers had to be translocated into these reserves to attempt to re-establish populations.

Besides poaching and habitat loss, the $7.5 trillion in infrastructure projects like roads, dams and mines that will be invested in Asia over the next decade threatens tiger landscapes. A focus only on core sites and protected areas like reserves, instead of larger landscapes, could be seen by developers and politicians as a green light to move forward with infrastructure projects outside of core sites.

The authors insist that conservationists and governments must be involved in helping design infrastructure projects to mitigate their impacts on tigers both inside core sites and in current and potential forest corridors. A recently built oil depot in India's Terai Arc, for example, severed a vital elephant and tiger corridor. Conservationists are now in litigation to remove the depot. Early intervention could have avoided this.

"Following the St. Petersburg Declaration, Nepal has committed to the goal of doubling wild tiger numbers across our country by 2022," said Deepak Bohara, Nepal's Minister for Forests and Soil Conservation. "This analysis shows that it can be done, not just in Nepal, but, if done right with careful study and planning, across the entire tiger range. It is also worth noting that tiger conservation provides carbon credits, protects water resources, and complements community development efforts. Thus, it is important to promote regional cooperation to maintain a healthy tiger corridor between different reserves."

Nowhere to hide: Tigers threatened by human destruction of groundcover

The elimination of ground-level vegetation is bringing another of the world's tiger subspecies to the brink of extinction, according to Virginia Tech and World Wildlife Fund researchers.

The Sumatran tiger, native to Indonesia, could be the fourth type of tiger to disappear from the wild. This is due, in part, because of deforestation and the loss of thick groundcover, also known as understory cover, said Sunarto, lead scientist on a study that is the first to systematically investigate the use of both forests and plantation areas for tiger habitat.

Although tiger's prefer forest to plantation areas, the study found that the most important factor was that availability of thick ground-level vegetation which apparently serves as an environmental necessity for tiger habitat, regardless of location.

"As ambush hunters, tigers would find it hard to capture their prey without adequate understory cover," said Sunarto, who earned his doctorate at Virginia Tech and now is a tiger expert for the World Wildlife Fund-Indonesia (WWF-Indonesia). "The lack of cover also leaves tigers vulnerable to persecution by humans, who generally perceive them as dangerous."

Within forest areas, tigers also strongly prefer sites that have low levels of human disturbance as indicated by their preference for areas closer to forest centers and farther from human activity centers such as bodies of water and areas bordering plantations and towns.

Tigers occupy only around 7 percent of their historic range. Estimates place the current wild tiger populations at as few as 3,200 tigers, including only about 400 Sumatran tigers, which are listed as critically endangered on the International Union for Conservation of Nature Red List of Threatened Species.

"These study results indicate that to thrive, tigers depend on the existence of large contiguous forest blocks," said study co-author Marcella Kelly, an associate professor in Virginia Tech's Department of Fish and Wildlife Conservation and Sunarto's graduate advisor.

The Indonesian government has set aside many areas and national parks for the conservation of endangered species but about 70 percent of tiger habitat in Sumatra, an island in western Indonesia, remains outside these protected areas. The preservation of such habitats, which requires support from government, landowners, and concession holders, is critical for conservation of the species, the study authors emphasize.

A recently published Indonesian presidential decree on land use in Sumatra points out the importance of building wildlife corridors between critical areas, where commitments from concession owners are key to successful implementation.

"Even with current legal protection for the species, tigers are not doing well in many places, especially those outside protected areas," Sunarto said. "As long as forest conversion continues, tigers will require active protection or they will quickly disappear from our planet."

The study is the first of its kind to systematically investigate the Sumatran tiger’s use of different land cover types for habitat.

The study concludes that in order to protect tigers, it is critical to stop clearing Indonesia's remaining natural forests for plantations. With adjustments in management practices on existing plantations to include more understory and riparian forest corridors, tigers could use a mosaic of forest patches across fragmented landscapes.

"We hope that plantation managers and concession owners can use the recommendations of this report to apply best management practices to further protect Sumatran tigers from extinction," said Anwar Purwoto, director of the Forest, Freshwater, and Species Program at WWF¬Indonesia.

"Ensuring that tigers are able to roam freely in natural forests and restored habitat is crucial to their survival," said co-author Sybille Klenzendorf, head of WWF's species program, who earned her master's and doctorate degrees in wildlife science from Virginia Tech. "This study is a reminder of just how important it is for us to protect the natural forests that tigers and other animals rely on."

The report was published in the Public Library of Science's online journal PLoS ONEon Jan. 23, and was a collaboration between the university and WWF, with support from the Indonesian Ministry of Forestry.

Human activities threaten Sumatran tiger population

Sumatran tigers, found exclusively on the Indonesian island of Sumatra, are on the brink of extinction. By optimistic estimates, perhaps 400 individuals survive. But the exact the number and locations of the island's dwindling tiger population has been up for debate.

Virginia Tech and World Wildlife Fund researchers have found that tigers in central Sumatra live at very low densities, lower than previously believed, according to a study in the April 2013 issue of Oryx -- The International Journal of Conservation.

The findings by Sunarto, who earned his doctorate from Virginia Tech in 2011, and co-researchers Marcella Kelly, an associate professor of wildlife in the College of Natural Resources and Environment, and Erin Poor of East Lansing, Mich., a doctoral student studying wildlife science and geospatial environmental analysis in the college, suggest that high levels of human activity limit the tiger population.

Researchers studied areas and habitat types not previously surveyed, which could inform interventions needed to save the tiger.

"Tigers are not only threatened by habitat loss from deforestation and poaching; they are also very sensitive to human disturbance," said Sunarto, a native of Indonesia, where people typically have one name. "They cannot survive in areas without adequate understory, but they are also threatened in seemingly suitable forests when there is too much human activity."

The smallest surviving tiger subspecies, Sumatran tigers are extremely elusive and may live at densities as low as one cat per 40 square miles. This is the first study to compare the density of Sumatran tigers across various forest types, including the previously unstudied peat land. The research applied spatial estimation techniques to provide better accuracy of tiger density than previous studies.

Sunarto, a tiger and elephant specialist with World Wildlife Fund-Indonesia, collaborated on the paper with Kelly, Professor Emeritus Michael Vaughan, and Sybille Klenzendorf, managing director of WWF's Species Conservation Program, who earned her master's and doctoral degrees in wildlife science from Virginia Tech. The WWF field team collected data in partnership with the Indonesian Ministry of Forestry staff.

"Getting evidence of the tigers' presence was difficult," Kelly said. "It took an average of 590 days for camera traps to get an image of each individual tiger recorded."

"We believe the low detection of tigers in the study area of central Sumatra was a result of the high level of human activity -- farming, hunting, trapping, and gathering of forest products," Sunarto said. "We found a low population of tigers in these areas, even when there was an abundance of prey animals."

Legal protection of an area, followed by intensive management, can reduce the level of human disturbance and facilitate the recovery of the habitat and as well as tiger numbers. The researchers documented a potentially stable tiger population in the study region's Tesso Nilo Park, where legal efforts are in place to discourage destructive human activities.

The study -- "Threatened predator on the equator: Multi-point abundance estimates of the tiger Panthera tigris in central Sumatra" -- indicates that more intensive monitoring and proactive management of tiger populations and their habitats are crucial or this tiger subspecies will soon follow the fate of its extinct Javan and Balinese relatives.

Hope for tigers lives in Sumatra

In time for the third annual International Tiger Day, recent findings from a camera trap survey in Sumatra, Indonesia have uncovered a burgeoning tiger stronghold on an island that typically makes headlines for its rampant loss of forests and wildlife.

Mr. Tomy Winata, an Indonesian businessman, conservationist and founder of Tambling Wildlife Nature Conservation (TWNC, which is a 450km2 privately managed concession), has carried out critical tiger conservation initiatives in the region since 1996, and recently partnered with Panthera, a global big cat conservation organization, to implement this successful survey.

The study's preliminary camera trap data recently indicated an unexpected density of six tigers per 100km2 in the southern region of TWNC. This estimate is nearly double the highest recorded for the island to date. These findings, including camera trap images of tiger cubs like that above, have identified Tambling, which is part of the globally significant Bukit Barisan Selatan National Park (BBSNP), as a beacon of hope for the last remaining 400-500 wild Sumatran tigers.

Panthera's CEO and tiger scientist, Dr. Alan Rabinowitz, stated, "The extraordinary tiger densities that have been discovered in Tambling are the tangible result of Mr. Tomy Winata's program not just to provide tigers sanctuary, but to protect them. Simply put, the main threat to tigers across their range is from poaching. Poaching is not a disease we can't see or a threat we can't identify. It can be beaten if the will is there to do so. Armed with a zero tolerance policy towards poaching, Mr. Tomy Winata and his team have successfully secured a significant area utilizing effective enforcement. This fact, coupled with good science and monitoring, has had the desired results; tigers are now breeding. Tambling is a model tiger conservation site that is giving the Sumatran subspecies a real chance not just to recover...but to thrive."

Prior to TWNC's efforts, Tambling's tigers were subjected to high levels of poaching and habitat loss. However, Mr. Tomy Winata's use of law enforcement patrols carrying out strict protection efforts, and maintenance of lowland tiger habitat and prey populations, has allowed Tambling to emerge as a key site for tigers in Sumatra and across their range. TWNC's initiatives have also benefited Tambling's local fishing community, which Mr. Tomy Winata has supported by providing villagers with employment opportunities, contributions to the community health clinic and school, student scholarships and more.

Mr. Tomy Winata stated, "I am doing all this because it is my belief that nature has provided us with everything we need to survive and live in this world, and yet so many people have taken from her for their own benefit without giving anything back in return. So I hope that my efforts in wildlife conservation and forest and ecosystem sustainability can be a role model for others, so that together we can help save Mother Nature and never forget where we came from."

Situated within a picturesque peninsula forming the southern tip of BBSNP, the TWNC region encompasses a privately managed concession which is critical to the protection and connectivity of core tiger populations in the larger BBSNP landscape -- an area extending 3,568 km2 that represents one of the largest contiguous protected regions of Sumatra.

A wild tiger cub walks past a camera trap in Tambling Wildlife Nature Conservation, Sumatra, 2013.

Panthera's tiger conservation efforts in southern Sumatra began in 2012 with the filming of the BBC Natural World documentary, Tiger Island, which follows Dr. Rabinowitz as he assesses the state of Mr. Tomy Winata's wild tiger conservation initiatives in Tambling.

Today, Panthera's wild cat scientist and post-doctoral fellow, Dr. Robert Pickles, is working with the TWNC team to extend the population density analysis to the northern region of TWNC and implement extensive habitat analyses to determine the vitality of Tambling's ecosystem. Expanding the reach and efficacy of the Tambling tiger conservation project, the field teams will soon implement a new monitoring software known as SMART to track evidence of illegal activities and better evaluate and target law enforcement efforts. Additional activities include assisting local authorities with park boundary delineations and determining additional threats and their solutions, besides poaching, to tigers, their prey, and their habitat.

Through this joint initiative, Panthera is working with Mr. Tomy Winata and TWNC to establish its first 'Tigers Forever Legacy Site.' Dr. Rabinowitz concluded, "There would be no greater legacy than creating safe havens for tigers where the legacy is that they live on, in the wild forever. Together with TWNC, we're one step closer to that becoming a reality."