Climate Change & Anthropocene Extinction 31: ‘New’ great ape species – directly at risk of extinction

Say hello to Pongo tapanuliensis, or ‘the Tapanuli orangutan’ – a close relative of yourself who had been hiding in plane sight on the Indonesian island of Sumatra.

Sadly, unless hunting and deforestation are halted, you can also immediately say goodbye – as just 800 individuals remain of this newly discovered ape species, living scattered across a fragmented rainforest of about 1,000 square kilometres.

Pongo tapanuliensis orangutan species
Pongo tapanuliensis, the ‘new orangutan species’, compared to the Sumatran orangutan. Excluding the genus Homo there are now seven great apes known to science that are alive today…

Evolutionary Anthropology – it’s good to know your own family, as it’s good to know yourself

The Anthropocene Extinction’ is the world’s ugliest word named after us, humans. Here is what it implies: Earth may be home to over a trillion species. Most we don’t know, often because they’re very small. It means in the Anthropocene Extinction we are killing species we haven’t even met, species we haven’t even documented, species we didn’t even know were there – before they were gone for good.

Rarely though, would such undocumented endangered biodiversity include a great ape.

Today though it does. It is cause for celebration, and a lot of other emotions. We take a look at the face of a new family member, and pronounce its name: ‘Tapanuli’. We also have to take a look in the mirror, to see ourselves. Sapiens. 800 versus 8 billion – the first a peaceful vegetarian, the second a species with a bad temper – that’s also armed. We are the estranged family member here…

The joyful news: 88 years after Bonobo someone else is ‘New to Science’!

Can you discover an already inhabited land? Can you claim discovery of a species that must have made eye contact with humans many many times before?

It’s wording of course – but what we can say is that there is a great ape that’s new to science that is still alive today, and that the date for that truly remarkable news is November 2, 2017.

What we can also say is that this news was announced by a large international research team led by the Evolutionary Genetics Group of the Department of Anthropology, at the University of Zurich.

Yes, you read that right, Anthropology, because we are talking about a very close relative here!

The last time there was similar news of this magnitude was in 1929, when the bonobo (Pan paniscus) was recognised as a separate species, distinct from the common chimpanzee.

And the chance it will happen again, yet another great ape species, still unknown today? Well, this may be it – also considering the speed at which remaining great ape habitat is destructed globally…

Pongo tapanuliensis must have lived in close human contact for thousands of years. But of course it’s a huge hit for the journal Current Biology and especially the authors to first publish evidence (PDF) that this small remnant primate population is actually a separate species of orangutan – and one that is actually more closely related to the Bornean orangutan than to its closer neighbour, the Sumatran orangutan.

Including us and the Neanderthal there were 8 great apes, we thought

Scientists prefer to refer to ‘great apes’ as homonidae or homonids, and that’s a very suited name as it emphasizes that these tree-loving animals are our closest relatives – and that in fact humans too are a great ape – being part of this same family of primates.

If you would ignore complexities like subfamilies or tribes, and exclude distant ancestors, the taxonomic classification within our homonidae family used to be quite tidy, as [a bit like your own family tree, four grandparents and eight great-grandparents, but then in reverse] you could neatly split our family into four main branches with two species each.

That would get you to 8 different homonid species in total – the 8 great apes.

Now half of our family only lives in or close to the Congolese forests of Central Africa. That is the genus Gorilla – with the western (lowland) and eastern (mountain) gorilla as two species, the genus Pan, with the common chimpanzee and the bonobo as again two separate species.

Then there is the great ape genus of humans (Homo), with Homo sapiens as sole surviving species since the very recent [40ka BP, possibly 12ka BP] extinction of Homo neanderthalensis [arguably the first victim of the Anthropocene Extinction, together with the ice age megafauna].

And then the remaining homonid genus – Pongo – lives in Southeast Asia exclusively and was thought to also exist of two living species, the Sumatran orangutan and the Bornean orangutan.

Now the new research shows that Pongo is actually the richest homonidae genus, as it contains not two, but three separate species, including the newly discovered (or rather newly described to science) species of Pongo tapanuliensis.

Neanderthal was the first great ape driven to extinction by that other great ape, homo sapiens. Tens of thousands of years later the tapanuli orangutan could be the second close family member in line to be slain

That means we all have another cousin to celebrate and the total number of great apes would be nine. But then tapanuliensis, or the tapanuli orangutan, could soon go the same route as our slain brother: Neanderthal.

Although the IUCN has not yet had the chance to officially determine the conservation status, all indicators show Pongo tapanuliensis is a critically endangered primate species – with a smaller total population size even than the critically endangered mountain gorilla.

The links to climate change

So, this series is about the links between climate change and Earth’s biodiversity crisis, and we have seen (in part 29) that sometimes climate change can indeed pose an immediate extinction threat to an already endangered primate: the Madagascan greater bamboo lemur.

We’ve also seen (in part 30) that climatic droughts can wreck havoc in the remaining rainforests of Sumatra – and that subsequent forest fires lead to global spikes in CO2 emissions, in turn linking these rainforest droughts to the wider global climate story.

These Sumatran droughts have a strong link to El Niño though, and thus far there’s no clear evidence that either El Niño becomes more frequent or in general that precipitation would decline over Indonesia as a result of 21st century climate change. (It’s a different story for the other three remaining expanses of tropical rainforest, that are all likely to experience increasing droughts under a global average temperature rise. This goes for the Central American rainforests, the Amazon rainforest and probably also the Congolese rainforests.)

‘How to survive’, and telling the human history tale

For the sake of the Tapanuli orangutan’s continued survival it would be good to focus on a far more immediate threat: Homo sapiens – our direct actions, our deliberate actions. For Sumatra prime concern is ongoing slash and burn deforestation by the palm oil industry. And that other prime concern is hunting.

So let’s stop using palm oil, and let’s stop burning Sumatran rainforests. Let’s also stop killing our own family members. It would make Earth a nicer place, and the human history a much nicer tale to tell to our children.

© Rolf Schuttenhelm |

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