I wrote a few moths ago, about a picture taken in Java, which purported to show a living Javan tiger. As with many similar photos, it was of low resolution, which in many situations, would appear suspicious. If you are on safari in Java, you would think that you would take a high resolution camera, and that this would be within reach at all times, as such the resolution is not really explained well enough.
The latest study has been started after a hair was tested and found to be from a Javan tiger – but recently.
Now, before I say anything, I have to say that I would love the Javan tiger to still survive. However, the simple fact is that they have not been seen in the wild since the early 1980s.
Furthermore, there was a false DNA test, not that long ago, where the DNA from a brown bear was mistaken for the DNA of a polar bear. This is not to dispute the sample, but it seems more likely that a mistake has been made on the hair (or that the hair is actually 50 years old) than that Javan tigers have been living unseen for all that time.
A Sumatran tiger reaches sexual maturity at 3-4 years. That means that 50 years is 12-17 generations. The 50/500 rule, says you need 50 individuals to combat inbreeding, and 500 to combat genetic drift (where small genetic traits can become common and then standard, changing the whole population). As of 2010, Java had around 10,000 hectaires of forest left (38 square miles), though upland rainforest has an area of around 85,000 or 328 square miles. Now, in Sumatra, the Tiger density rarely goes above around 1 tiger in 13 square miles – meaning that this upland rainforest can only support around 25 tigers.
While I would love for the Javan tiger to be found alive, it is highly unlikely. Were it found alive, it is likely to replace the Amur Leopard as the most endangered big cat in the world, and its long-term survival would be very hard to help.
Could the Sumatran tiger return to Java, through a translocation? It is certainly true that the Sunda Asian tigers (those on the Indonesian islands) are the closest related. It is thought that they lived as one population until the sea level rose, cutting off the land bridges between the islands – this would have occurred during the last Glacial maxumum around 20,000 years ago, with the submerging starting around 18,000 and completing around 5000 years ago. This is only 4000 generations at the outside, down as low as 1000, just 5000 years ago. This is just a blink of an eye in evolutionary scales (it is thought that Lions and Tigers split 4-5 million years ago), so while there may well be genetic differences between the Sumatran and the Javan tigers, these will not be great enough to stop the Sumatran tiger filling the evolutionary hole left by the Javan tiger. What is clear, is that, should the Javan tiger survive, it is incredibly close to extinction, and with the Sumatran tiger continuing its slide towards extinction (as a result of lost habitat), a translocation before the population recovers would endanger the population in Sumatra, as well as all individuals that move to Java.
The current population is thought to be around 400 (though other sources estimate 600). As such, as other tiger subspecies have been recovering, it is clear that the Sumatran tiger is not recovering at the same rate (the aim was to double tiger populations between years of the tiger (China). While many, such as the Indian tiger, did, others did not. Clearly, a wild population of 400 is not large. While it may be possible to translocate some to Java, it would have to be clear that their life there would be less dangerous than in Sumatra, and that is going to be hard to demonstrate.
Below, you will find a short video about the last tigers of Java.
