Study States That 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, according to a new paper from scientists at the Smithsonian Conservation Biology Institute and other world-leading conservation researchers. The study is the first assessment of the political commitment made by all 13 tiger-range countries at November’s tiger summit to double the tiger population across Asia by 2022.

“A Landscape-Based Conservation Strategy to Double the Wild Tiger Population” in the current issue of Conservation Letters, finds that the commitment to double tiger numbers 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.

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 study co-author John Seidensticker, head of SCBI’s Conservation Ecology Center. “By saving the tiger we save all the plants and animals that live under the tiger’s umbrella.”

The paper’s 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 doubling or tripling the population 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 repopulated 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 recolonize because these reserves are not connected to other reserves. Consequently, wild tigers had to be translocated into them 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 threaten tiger landscapes. Developers and politicians may see a focus only on core sites and protected areas like reserves, instead of larger landscapes, as a green light to move forward with harmful 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.

“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 Eric Dinerstein, chief scientist at the U.S. World Wildlife Fund and a co-author of the study. “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.”

SCBI and partnering organizations in the Global Tiger Initiative are currently hosting a monthlong course in Thailand aimed at teaching wildlife officers, field managers and researchers from tiger-range countries best practices to bolster the animals’ numbers. The goal of the Global Tiger Initiative—a project that involves SCBI, the World Bank Group and partnering organizations—is to double the number of tigers in the wild by 2022—the next year of the tiger.