The tiger is not only a charismatic example of megafauna, but also an umbrella species. As a predator at the top of the food chain, tigers maintain the balance between herbivores and the vegetation upon which they feed. Thus, by protecting and conserving tigers, we also help preserve biodiversity and a whole suite of ecological processes within their habitat.
Tigers are mostly solitary, which is why they need a large territory to survive. Unfortunately, habitat loss, along with poaching, has significantly brought down tiger populations. According to the World Wildlife Fund, the world has lost 97 percent of wild tigers in just over a century and less than 3,500 tigers remain in the wild today.
There are currently 13 tiger-range countries in the world, including Indonesia with six priority Tiger Conservation Landscapes (TCLs) in Sumatra, i.e. protected areas to conserve tigers: Ulumasen-Leuser, Kampar-Kerumutan, Bukit Tigapuluh, Kerinci Seblat, Bukit Balai Rejang Selatan and Bukit Barisan Selatan.
In addition to the Sumatran tiger, Indonesia used to be home to Bali and Javan tigers, but they became extinct in the 1960s due to rampant poaching and abuse. A 2010 study by the Smithsonian Institution estimated that there are no more than 400 tigers in Sumatra. With only a few tigers remaining in Sumatra, TCLs have become more important than ever.
A recent joint study by researchers from the University of Minnesota, RESOLVE, Stanford University, the Smithsonian, the University of Maryland and the World Resources Institute revealed that saving tigers from extinction is within reach as long as their remaining landscapes are effectively monitored and protected. The study suggests that less than 8 percent of all 76 TCLs (nearly 79,600 square kilometers) was lost from 2001-2014, which was less than anticipated given that tiger habitats generally span fast-growing developing economies.
Other encouraging news is that the Khata corridor in the Terai Arc Landscape, Nepal, connecting Nepal’s Bardia National Park and India’s Katerniaghat Tiger Reserve, gained tree cover over 2.7 percent of its area in the last 14 years, which has likely resulted in an increase of 32 tigers between 2009 and 2013 in Bardia. Nepal and India in general also experienced 61 and 31 percent increases in tiger populations from 2001-2014 thanks to community-driven forestry programs and antipoaching efforts.
Unfortunately, their findings for Southeast Asia were not as rosy as those for Nepal and India. The vast majority ( 98 percent) of tiger forest habitat loss occurred within just 10 TCLs in Indonesia and Malaysia. Indeed, our analysis based on the Global Forest database revealed that the six priority TCLs in Indonesia have lost 12.5 percent of their forests in the past 14 years. Kampar-Kerumutan experienced the highest tree cover loss of 3,389.5 sqkm ( 34 percent of its total area), followed by Bukit Tigapuluh with almost 3,000 sqkm tree cover loss ( 42 percent) and Kerinci Seblat with 2,361.60 sqkm tree cover loss ( 8.35 percent).
However, Bukit Balai Rejang Selatan, Bukit Barisan Selatan and Leuser experienced less than 270 sqkm (less than 9 percent) tree cover loss, with Leuser only experiencing tree cover loss of 0.09 percent of its total area, suggesting that these landscapes are relatively intact and there is still hope for protecting Sumatran tigers’ remaining habitats.
Our analysis also revealed that more than 12,000 sqkm of oil palm and timber concessions overlap with 16 percent of the six priority TCLs in Sumatra, strongly suggesting that the conversion of natural forest to plantations for agricultural commodities has become a major driver of tiger habitat loss in Indonesia.
Somewhat unsurprisingly, the three TCLs that recorded the highest tree cover loss also recorded major overlaps with oil palm and timber concessions. These concessions overlap with 48 percent of Kampar Kerumutan’s landscape, 42 percent of Bukit Tigapuluh’s and 13.5 percent of Kerinci Seblat’s.
We cannot afford to lose more Sumatran tigers. Many have suggested that habitat loss, poaching of tigers’ prey and tiger poaching are three major threats to tiger populations in Sumatra. Our analysis highlighted the threats posed by oil palm and timber plantations to defined TCLs in Indonesia, most of which have been designated as national parks or wildlife reserves. Therefore, merely turning tiger habitats into conservation areas is not enough. Collaborative efforts are needed to ensure that habitats for one of the most iconic species are protected and restored.
To protect existing Sumatran tiger habitats, continuous monitoring is needed. Satellite-driven data to monitor near real-time forest change via Global Forest Watch will be useful to preempt further efforts to encroach upon or convert TCLs for other land uses.
The involvement of locals both to protect habitat loss and to combat illegal tiger poaching is crucial.
The government should integrate the management of TCLs with the land-use plans of surrounding regions, including in addressing the challenges associated with human population growth. Finally, restoring degraded or deforested areas within TCLs will be critical. The lesson from Nepal, which succeeded in increasing its number of tigers by protecting and expanding tree cover in its TCLs, provides us with a glimpse of hope.