In the rainforests of Sumatra live the last of the Sunda or “Island Tigers” – a distinct group of tiger subspecies once found across Indonesia’s Sunda Island chain. Until only a few decades ago, tigers roamed the islands of Bali and Java. Today, the Bali and Javan tiger subspecies are extinct.
The Bali tiger (Panthera tigris balica) was the smallest of the tiger subspecies and was last positively recorded in the late 1930’s in Bali Barat National Park. Pushed to the edge by growing human populations, hunted for sport, and persecuted by villagers as a pest, it was declared extinct not long after the end of the Second World War.
The Javan tiger (Panthera tigris sundaica), which is more similar to the Sumatran, held on longer into the 20th century. Between 1900 and 1975, the population on Java almost tripled from 28 million to 85 million people. During this time, the annual production of rice was unable to keep up with population demands, resulting in the clearing of forests for rice cultivation. In 1938, tropical forests covered 23% of the island; By 1975, only 8% remained.
As habitat for Javan tigers dwindled, the tigers and their prey were hunted and poisoned during intensified human-wildlife conflicts. Tropical forests were converted to rice fields or teak and rubber plantations, further fragmenting tiger habitat.
During the 1960‘s, disease ravaged Rusa deer, the tigers’ most important prey, further weakening the species. Civil unrest in Java after 1965 pushed militants into reserves killing many of the remaining tigers.
In the following decades, the remaining Javan tiger population was restricted to only three reserves on the island that lacked adequate protection for them and their prey species. Confirmed sightings became increasingly infrequent and in 1984 the last confirmed Javan tiger was killed outside Halimun Reserve in west Java.
To follow up on alleged sightings, a survey was conducted with the help of WWF between 1993 and 1994 using camera traps in east Java’s Meru Betiri National Park. No tiger tracks or other signs were found in the survey. The cameras revealed no tigers, few prey and many poachers. After the final report of this survey, the Javan tiger was declared extinct. Unofficial “ghost sightings” occasionally occur, but they are likely just that – ghosts.
Clearance of Java’s rainforests for agricultural expansion led to the extirpation of the Javan tiger and intensified other factors that led to what biologists refer to as an “extinction vortex”: a series of mutually reinforcing feedbacks that drives a population downward to extinction.
The same forces of rapid population growth, forest clearance for agriculture, rampant oil palm development and the ongoing persecution of tigers and their prey by poachers are now threatening the Sumatran Tiger (Panthera tigris sumatrae) – the last of the Sunda Tigers.
We can’t bring back the Bali and Javan tigers, but we can save the Sumatran Tiger and pull it out from the vortex of extinction.