There are various subspecies of tiger around the world, all desperately clinging on. The Bengal tiger of the Indian subcontinent is now the most numerous, although it covers just a tiny portion of its original range and less than 3,000 individuals are left in the wild. Three species – the Caspian tiger, the Javan tiger, and the Bali tiger – are already extinct.
Long ago, tigers were decimated by hunting. While habitat loss is now a bigger threat, they are still affected by illegal poaching due to their sought-after skins, perceived threat to humans, and demand for their body parts for use in traditional Asian medicine.
The researchers found that between 2000 and 2012, the Sumatran tiger’s habitat shrunk by 17 percent. Nevertheless, they describe the threats of deforestation and habitat fragmentation as “imminent and often irreversible”, highlighting the immediate danger the tigers are in, but also signifying a ray of hope by suggesting that something can still be done to save the Sumatran tiger.
To be viable in the long term, tiger populations need 30 breeding females. The researchers only found two areas big enough to sustain this number.
"The erosion of large wilderness areas pushes Sumatran tigers one step closer to extinction," said lead author Matthew Luskin, previously a graduate student at the University of California, Berkeley, in a statement. "We hope this serves as a wakeup call."
What is needed now is for logged areas to be reforested, so that Sumatran tigers can once again spread out into more of their natural range. However, the researchers fear that this probably won’t occur, so it is essential to protect the two sites viable for breeding populations.
"Large-scale reforestation is unlikely," said co-author Mathias Tobler of San Diego Zoo Global. "If we are going to save Sumatran tigers in the wild, the time to act is now."