Bornean Orangutan subspecies.

[Pertinax]

Does anyone have any information(or links) about the 3 subspecies of Bornean Orangutan which are nowadays regarded as being seperate from each other?

How do they differ in characteristics- can they be identified by physical appearance for example?

Are any moves being made to try and differentiate them in the captive population?

 

[MikeG]

The 3 subspecies are:
P. pygmaeus pygmaeus - western Borneo, including southern Sarawak.
P. pygmaeus morio - north & east Borneo, including Sabah.
P. pygmaeus wurmbii - central & southern Borneo.
There's apparently some difference in fur coloration, with morio being generally darker ['morio' is a Latin word for a type of dark brown stone].
There's been a suggestion - based on craniometric measurements - that P. p. wurmbii may be closer to the Sumatran Orang-utan (P. abelii) than to the other Bornean forms, but this has yet to be confirmed as far as I'm aware.

 

[MikeG]

Are any moves being made to try and differentiate them in the captive population?

I think the simple answer to this is - No.
According to the Orang-utan SSP "Because holding space is limited, the Bornean population is not managed to the subspecies level in captivity – populations of sufficient size to be viable cannot be maintained in captivity."

I wonder about orang rescue & rehabilitation centres within Borneo itself - i.e. whether rescue animals have ever been released or translocated into areas populated by other subspecies?

 

[Pertinax]

I think the simple answer to this is - No.
According to the Orang-utan SSP "Because holding space is limited, the Bornean population is not managed to the subspecies level in captivity – populations of sufficient size to be viable cannot be maintained in captivity."

Plus all the Orangutans which have been bred for several generations in captivity now must resemble a real 'cocktail' of these three subspecies, in much the same way as Bornean/Sumatran hybrids used to be mistakenly produced before their true classification was realised.

Possibly in Borneo itself there has been little or(hopefully) even no mixing if any rescued animals have been re-released at least in the same general region of their birth, rather than in a completely different part of Borneo.

 

[Taisha]

I wonder about orang rescue & rehabilitation centres within Borneo itself - i.e. whether rescue animals have ever been released or translocated into areas populated by other subspecies?

Here you are: Day 4: Three Orangutans Return to East Kalimantan | BOS Foundation

 

[Pertinax]

Here you are: Day 4: Three Orangutans Return to East Kalimantan | BOS Foundation

Thankyou Taisha. Very interesting.

 

[TeaLovingDave]

Plus all the Orangutans which have been bred for several generations in captivity now must resemble a real 'cocktail' of these three subspecies, in much the same way as Bornean/Sumatran hybrids used to be mistakenly produced before their true classification was realised

In any case, I suspect that the species is pretty much at the point where it is wiser to keep it around as non-subspecific mongrels, rather than trying to keep subspecific purity and ending up with multiple inbred lines doomed to extinction.