A tiger subspecies thought to be extinct for nearly half a century has possibly been spotted again in Indonesia, raising hopes that the animals still exist somewhere on their lush island, reports Jon Emont for the New York Times

One of the nine subspecies of tiger, the Javan tiger was once a dominant predator on the tropical island of Java. In the 18th century, they were so numerous on the island that Dutch colonizers put a bounty on the head of the animals to encourage their killing. Though Javan locals refrained from killing the creatures unless they did harm, as human populations swelled many big cat encounters resulted in human deaths, according to A. Hoogerwerf 's 1970 book Udjung Kulon, The Land of the Last Javan Rhinoceros. The Javan tiger's numbers dwindled over the next two centuries.

By the 1940s, hunters reported seeing few if any of them on the island. The remaining Javan tigers had fled to the mountainous areas and national parks where humans couldn't easily follow. The last positive confirmed sighting of the big cats occurred in Java's Meru Betiri National Park in 1976. And in 2003, they were listed as extinct by the International Union for the Conservation of Nature's Red List.

Even so, wildlife enthusiasts haven't given given up hope that the tigers still may be out there. Spurred on by rumors and reported glimpses, ​people have regularly set camera traps since the 1990s in a bid to capture the reclusive tigers. But they've had no luck getting the shot, Jeremy Hance of Mongabay reported in 2012.

Last month, however, a wildlife ranger has photographed what may be the first definitive sighting of a Javan tiger in more than 40 years, reports Emont​. Workers in West Java's Ujung Kulon National Park spotted a big cat that appeared different than any of the species usually seen in the area, and when the pictures were published online, speculation swirled around whether this cat could be the one.

“This used to be Javan tiger habitat,” Mamat Rahmat, the head of conservation at the park, told the local news media, according to Emont. “We hope that they’re still there.”

Experts are skeptical, however, noting that the video of the spotting appears to show a cat moving more like a leopard than a tiger. The Javan leopard is listed as "critically endangered" by the IUCN, but still lives in some sections of the island.

Nonetheless, the World Wildlife Fund is now supporting an expedition to track down whether the Javan tiger could still exist, Emont reports.