Is the Javan tiger still extant?

DesertRhino150

DesertRhino150

Well-Known Member
15+ year member
I have just seen this rather interesting paper that was published in the journal Oryx yesterday. The Javan tiger was only classified as extinct by the IUCN in 2008, although the last confirmed sighting was from 1976.

A sighting was made in 2019 of a tiger on a community plantation near the village of Cipendeuy in the forest of South Sukabumi, West Java. More interestingly, a hair was found left on a fence where the tiger had jumped between the village road and the plantation. This hair was recovered for genetic analysis.

When compared against the Javan leopard, Bengal tiger, Sumatran tiger and a museum specimen of a Javan tiger, the hair was found to have 96.87% sequence similarity to the Bengal tiger and 97.06% similarity to the Sumatran tiger. When arranged on a phylogenetic tree, the putative Javan tiger hair and museum specimen of the Javan tiger were in the same distinct group. The fact that such intact genes were able to be extracted from the recovered hair help show that it was fresh rather than preserved.

While the authors of the paper do say that they believe the hair is from a Javan tiger, they also say its continued existence will only be proved with further sightings and genetic analysis.

The full paper can be seen here:
Is the Javan tiger Panthera tigris sondaica extant? DNA analysis of a recent hair sample | Oryx | Cambridge Core
 
If there are a few left, the species would no doubt be functionally extinct by now but it would be wonderful news if they could be photographed and studied.
 
JVM said:
If there are a few left, the species would no doubt be functionally extinct by now but it would be wonderful news if they could be photographed and studied.
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Take the few remaining into captivity and systematically crossbreed them with Sumatran tigers. Rewild their descendants into protected habitat on the island of Java many years later.

Alternatively, copy what was done with the Florida panther in the 1990's. Release several female Sumatran tigers into known Javan tiger habitat and let nature take it's course.

If enough variable habitat for a sustainable population for Javan tigers on the island of Java isn't present, then send surviving female Javan tigers to the island of Sumatra. Release them into known Sumatran tiger habitat and let nature take it's course.

With the above plan, any surviving male Javan tigers could be taken into captivity to crossbreed with Sumatran tigers. For additional insurance purposes.

Either way, the end result would be a subspecies saved from extinction.
 
Cross breeding them with Sumatran tigers is the only real option, but that dilutes the Javan genes into near irrelevance.

Crossing "Florida" panthers with western cougars worked well enough as there is actually a fair amount of habitat in Florida, cougars are very adaptive to rural and suburban environments, and the genes are pretty much the same. I am not convinced there is enough viable habitat in Java for any sustainable population of tigers with any sort of necessary genetic diversity.

IMO captive breeding by crossing with Sumatran tigers is the only realistic option, but again that dilutes whatever genetic differences there are and we result in simply a generic Sunda tiger.

There are no real "good" options to "saving" the Javan tiger, assuming they still exist.
 
Before we decide what should have done with surviving Java tigers, we should know their numbers imo.
If the numbers ("genetic material") is less then 5 individuals, it doesn't make sense to crossbreed with Sumatran tigers particulary as long as the later are still critically endangered, so that we need pure Sumatran to safe themselves from extinction. In this case, it would make more sense to crossbreed the last Java tigers with generic tigers. You will have mixed tigers then anyway. The only difference is that they are not as close to the original as if you would do it with Sumatrans only.
If the numbers of pure Java tigers are higher (what I doubt) and with an useful sexratio, then it would make probably sense to catch them and try to breed them in-situ.
However: I don't think it comes to one of these options.
 
zoomaniac said:
Before we decide what should have done with surviving Java tigers, we should know their numbers imo.
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That is exceedingly difficult to find out, they are a ghost as it is. At best we are looking at a few animals.
If the numbers ("genetic material") is less then 5 individuals, it doesn't make sense to crossbreed with Sumatran tigers particulary as long as the later are still critically endangered, so that we need pure Sumatran to safe themselves from extinction. In this case, it would make more sense to crossbreed the last Java tigers with generic tigers. You will have mixed tigers then anyway. The only difference is that they are not as close to the original as if you would do it with Sumatrans only.
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Yikes, I don't agree with that. First, there are a number of viable Sumatran tigers in captivity that are genetically redundant so as to be able to be used for a project like this. Second, while Sumatran are critically endangered in the wild they are relatively well represented in captivity (see point 1). Third, at least diluting with Sumatran keeps them generic Sunda tigers, diluting with other generic tigers makes them as useless as any other generic tiger for wild conservation. If we go that route we may as well try and re-wild generic tigers and release them on Java and Bali to fill the ecological niche.
However: I don't think it comes to one of these options.
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I agree, basically this is all fantasy theorizing, these animals may as well be bigfoot - and more bigfoots have been spotted in the last 10 years than these cats.
 
I think the best thing to do would be to prep wild areas in Java for tigers. I think ensuring some connectivity between protected areas and making sure those areas are relatively safe from poaching as well an ensuring the needs of local communities are met. Sort of like how African Parks approaches securing protected areas.

Then, I think the best thing is to introduce zoo-born Sumatran tigers. If there are any Javan tigers left, their genetic pool is going to be in such poor shape that at least we can still keep them as Sunda tigers by reintroducing another island subspecies.

I think the use of Sumatran tigers is the only way Java will ever have a viable tiger population
 
SwampDonkey said:
That is exceedingly difficult to find out, they are a ghost as it is. At best we are looking at a few animals.
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What is your definition of "a few"? How long should the search go?

SwampDonkey said:
Third, at least diluting with Sumatran keeps them generic Sunda tigers, diluting with other generic tigers makes them as useless as any other generic tiger for wild conservation. If we go that route we may as well try and re-wild generic tigers and release them on Java and Bali to fill the ecological niche.
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You can turn it on every side you want, they will still be generic. Recreate real pure Java tigers is impossible, at least at the moment.
And yes, as long as there is no (longer) risk to mix with pure individuals and there would be a save, long term habitat, generic tigers could released on Java or Bali imo. Better then contaminate pure stocks.
 
tigris115 said:
I think the best thing to do would be to prep wild areas in Java for tigers. I think ensuring some connectivity between protected areas and making sure those areas are relatively safe from poaching as well an ensuring the needs of local communities are met. Sort of like how African Parks approaches securing protected areas.

Then, I think the best thing is to introduce zoo-born Sumatran tigers. If there are any Javan tigers left, their genetic pool is going to be in such poor shape that at least we can still keep them as Sunda tigers by reintroducing another island subspecies.
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Partially agree. However, first (and this is valid for my post also): Rewild predators like tigers is extremely difficult and expensive. Second: Release pure Sumatran Tigers in protected Areas of Java is a good idea imo, as long as a.) it is prooved that there is really no pure Java tiger is left there or b.) these individuals are managed outside of any other in-situ or ex-situ programm beside imports (What comes to Java, stays in Java).
 
zoomaniac said:
Partially agree. However, first (and this is valid for my post also): Rewild predators like tigers is extremely difficult and expensive.
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My main model would be lion reintroduction projects like the ones in Akagera in Rwanda and Coutada 11 in Mozambique

zoomaniac said:
Second: Release pure Sumatran Tigers in protected Areas of Java is a good idea imo, as long as a.) it is proved that there is really no pure Java tiger is left there or b.) these individuals are managed outside of any other in-situ or ex-situ program beside imports (What comes to Java, stays in Java).
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Tbh, I was gonna interbreed the two subspecies as, like I said, the remaining Java tiger population NEEDS these genes as, their genetic health is probably so far in the dumps that there's no way they can recover on their own and, even with managed breeding, without new genes, inbreeding depression would wipe them out.
 
Ah, I see. Maybe I have to be more precise as well: If there is not enough "genetic material", then there are only 2 ways: Let them die out definitely or mix them with other tigers. If you do the latter, then you must aware that they will be allways generic and will not have any conservation value in the way zoos and other wildlife organisations handle this at the moment and that all individuals, that you bring to an in-situ project on Java - no matter from which pure subspecies - will be lost for EEP etc.
 
zoomaniac said:
Ah, I see. Maybe I have to be more precise as well: If there is not enough "genetic material", then there are only 2 ways: Let them die out definitely or mix them with other tigers. If you do the latter, then you must aware that they will be allways generic and will not have any conservation value in the way zoos and other wildlife organisations handle this at the moment and that all individuals, that you bring to an in-situ project on Java - no matter from which pure subspecies - will be lost for EEP etc.
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I'd rather they be somewhat diluted than die out completely.
 
Truthfully, I fail to understand why subspecies simply must remain "pure", no ifs, ands, or buts about it.

Purity and purebreeding are entirely human concepts. Animals are rarely picky when it comes to choosing a mate. Hybrids are far more commonplace than typically admitted. Hell, some species even originated as hybrids!

Subspecies come about as a result of a species adapting to local conditions, and subsequently becoming isolated from the rest of the population.

Crossing a Java tiger, with a Sumatran tiger, would produce more tigers. Better still, the resulting cubs would be Sunda Island tigers! The far less common of the two tiger lineages.

Javan and Sumatran tigers are closely related, similar in size, predate on many of the same species, and live in similar habitats.

They have much to offer one another, assuming that the Javan tiger really is still alive and well IMHO.
 
Furthermore... it's not like crossbreeding Javans and Sumatrans would be equivalent to the still prevalent Bengal/Amur cross.

Bengals and Amurs are dissimilar in size, preferred prey, typical habitat, and are only related via both of them being continental tigers.

That being said...

A zooborn Bengal/Amur crossbred tigress named Tara was successfully rewilded to Dudhwa National Park in the late-70's. She died in 1992, having produced at least four litters of cubs.

In 1995, a male tiger sporting features typical to Amur tigers was spotted in Dudhwa National Park. DNA testing conducted some years later confirmed that this tiger, in addition to another from the same area, had Amur DNA. Of course, it could never be conclusively proven, but Tara is believed to have been the source.

A Siberian tiger in an Indian jungle? The saga of Tara the tigress has

Nature is a hell of a lot more adaptable than we give it credit for.
 
Wisp O' Mist said:
Truthfully, I fail to understand why subspecies simply must remain "pure", no ifs, ands, or buts about it.
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I agree with your above premises. That's just the thing, they are not even considered subspecies any longer (at least by most). Mainland and Sunda are the current recognized subspecies along with Northern and Southern clades for the mainland tigers, so mixing Sumatran and Javan makes a lot of genetic sense at this point (again, assuming the Javan still exist).

As such, a mixed Sunda subspecies is still of conservation value, a mixed Javan/Mainland would be of little to no conservation value. But any tiger mix would be of ecological value.

We still need evidence that there is even enough wild space left on Java for a sustainable population....and we still need to actually find a live tiger. A hair from 2019 is great, but that is a few years back and only a hair.

We literally have more evidence of bigfoot being real from the last 5 years than of these tigers.
 
If there are male and female Javan tigers, sperm and eggs could be used to produce embryos to be transplanted into female Sumatran tigers
 
I was confused about the Phylogenetic tree, the sample from suspecious hair and museum almost become the outer group of all the other tiger.
 
Well the first step is really habitat restoration. And that'll have outstanding benefits for not just tigers but a wide host of other critters. But use tigers as the umbrella species

Elephants could also be reintroduced to Java if that's an option
 
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