Australasian Western Lowland Gorilla Population

[Jambo]

Do you remember how old Rigo and Yuska were when they entered captivity?. I think there's a difference between gorillas that are reared by humans from birth to those that have the important first two years or even longer in the wild being raised other gorillas. I beleive they are as a result more normal in their behaviour than a hadraised zooborn.

Rigo was three when he arrived at Melbourne, Yuska was just two. It's quite notable to see how both were perhaps far more 'socially competent' compared to others who have been hand raised, such as Julia and G Ann. Julia too came from the wild but I believe she was taken in when she was less than a year old.

 

[Pertinax]

and the other has failed to produce surviving offspring in the Jersey troop.

Bambuti- known as Bahasha in Jersey, has a daughter born 2019 called Amari. But I think that she had a number of failed pregnancies before this successful birth.

 

[Zoofan15]

Rigo was three when he arrived at Melbourne, Yuska was just two. It's quite notable to see how both were perhaps far more 'socially competent' compared to others who have been hand raised, such as Julia and G Ann. Julia too came from the wild but I believe she was taken in when she was less than a year old.

The most detrimental effect on Julia’s formative years was being raised in the company of chimpanzees. Julia acquired a repertoire of chimpanzee behaviours that were interpreted as threatening/antagonising by silverbacks.

One thing that seems to come up a lot with hand raised apes is their inability to read the room - to know when to give others space etc. I read of an incident where Julia was repeatedly charging past Nandi, who was growing irritated; until Nandi snapped and slapped her. She would also (pre-contact) chest beat and posture at Jambo through the bars, causing him to shoulder charge the dividing wall. Tragically, this is what was primarily attributed to her death - she ignored Otana’s repeated commands to give Kimya and her newborn space.

There’s a comprehensive account of Julia’s background here:

The Integration of Julia

 

[Pertinax]

Rigo was three when he arrived at Melbourne, Yuska was just two. It's quite notable to see how both were perhaps far more 'socially competent' compared to others who have been hand raised, such as Julia and G Ann. Julia too came from the wild but I believe she was taken in when she was less than a year old.

Yes, three and two are quite typical ages for zoo imports and a lot of other pairs of similar age were imported to zoos in Europe and the USA during the 1950/60/70's, these are mostly the ones that turned out to be normal and later bred- though often only after having to be switched to fresh partners. Unsurprisingly its the very small babies that are the ones that suffer the worst desocialisation. Ganne was handraised from birth and no doubt spoilt, and she wasn't kept with other gorillas fulltime until going to Jersey. Julia was also very young and later imprinted largely on the Chimpanzees which formed her company I think.

 

[Zoofan15]

Yes, three and two are quite typical ages for zoo imports and a lot of other pairs of similar age were imported to zoos in Europe and the USA during the 1950/60/70's, these are mostly the ones that turned out to be normal and later bred- though often only after having to be switched to fresh partners. Unsurprisingly its the very small babies that are the ones that suffer the worst desocialisation. Ganne was handraised from birth and no doubt spoilt, and she wasn't kept with other gorillas fulltime until going to Jersey. Julia was very young and later imprinted largely on the Chimpanzees which formed her company I think.

I’ve similarly seen this with chimpanzees too where those removed as infants (before the age of three) are deprived of learning social behaviours such as mating and rearing young; while those who remain in their natural troop for a minimum of five years are largely unaffected. Those that are removed in between are effectively on a continuum of socialisation, where the extent of the damage varies.

Even though hand raised males (of both gorillas and chimpanzees) can often cohabit with females, whether they mate with them is another matter - with behavioural non-breeders being a common side effect.

As a side note, it’s interesting how many silverbacks of decades past were sterile. I recall hearing their susceptibility to previously common human diseases like mumps was often the cause.

 

[Trua]

I was told by a gorilla keeper at Melbourne Zoo it was due to the genetic representation of Orana and Kimya. Although I note that Kimya’s full sister Kipenzi has bred twice now at Mogo, this was with Kisane, who is a more genetically valuable male.

This is incorrect. Otana and Kimya should have had the opportunity to breed before her death.

 

[Jambo]

Bambuti- known as Bahasha in Jersey, has a daughter born 2019 called Amari. But I think that she had a number of failed pregnancies before this successful birth.

She had a single birth in 2013. A female offspring which died at six days old due to being born premature.

 

[Zoofan15]

This is incorrect. Otana and Kimya should have had the opportunity to breed before her death.

That’s what I was told by her keeper, though I recall a number of us speculating at the time that she was off contraception, with her failure to conceive theorised to be a result of living in a 1.1 (which is rarely conducive to successful breeding).

Females feel uneasy when they lack the support of other females against the silverback, who will otherwise have no recourse should they exert unnecessary force (similar to tyrant chimpanzee alphas, who seldom last long in the alpha position if there’s enough subordinates under them to oust them from that position).

 

[Trua]

That’s what I was told by her keeper, though I recall a number of us speculating at the time that she was off contraception, with her failure to conceive theorised to be a result of living in a 1.1 (which is rarely conducive to successful breeding).

Females feel uneasy when they lack the support of other females against the silverback, who will otherwise have no recourse should they exert unnecessary force (similar to tyrant chimpanzee alphas, who seldom last long in the alpha position if there’s enough subordinates under them to oust them from that position).

Ah okay that makes sense. It would be a huge shame if she was pregnant when she passed.

Do we know why females were never acquired? Hopefully they look at some from overseas now with Kimya gone

 

[Jambo]

Ah okay that makes sense. It would be a huge shame if she was pregnant when she passed.

Do we know why females were never acquired? Hopefully they look at some from overseas now with Kimya gone

I would honestly hope so. I do acknowledge my comments earlier on this were merely assumptions however I have reason to believe this may be the route Melbourne may end up taking now.

Imports can take a while (years even in some cases) so let's hope something is already organised, or worst comes worst, they act quickly!

From what I understand there's really not much otherwise they can do, Taronga are probably unlikely to send females across (at least in the present situation).

 

[Zoofan15]

Ah okay that makes sense. It would be a huge shame if she was pregnant when she passed.

Do we know why females were never acquired? Hopefully they look at some from overseas now with Kimya gone

To my knowledge she wasn’t pregnant, unless it was in the early stages (such an ectopic pregnancy). I would be surprised if her death was something reproductive related (not necessarily a pregnancy) but like a uterus infection/pyometra etc.

Melbourne will certainly need to work quickly to provide Kanzi with support as living in a 1.1 troop isn’t an option for the long term. It wouldn’t even surprise me to see her go to Mogo as a non-breeding female for 5-10 years until a breeding placement opens up elsewhere. It would be a double up to have her and her aunt breeding with Kisane.

 

[Jambo]

To my knowledge she wasn’t pregnant, unless it was in the early stages (such an ectopic pregnancy). I would be surprised if her death was something reproductive related (not necessarily a pregnancy) but like a uterus infection/pyometra etc.

Melbourne will certainly need to work quickly to provide Kanzi with support as living in a 1.1 troop isn’t an option for the long term. It wouldn’t even surprise me to see her go to Mogo as a non-breeding female for 5-10 years until a breeding placement opens up elsewhere. It would be a double up to have her and her aunt breeding with Kisane.

Melbourne previously announced Kimya's last pregnancy when she was just a few months pregnant, so unless they chose not to announce a pregnancy this time around; I agree it would probably be unlikely.

Transferring Kanzi out wouldn't really make much sense. As you mention, she's not needed at Mogo so a transfer there isn't justified at all. Additionally, if Melbourne were to acquire some additional females, Kanzi would still be required to provide additional support and balance out the sex ratio.

 

[Zoofan15]

Melbourne previously announced Kimya's last pregnancy when she was just a few months pregnant, so unless they chose not to announce a pregnancy this time around; I agree it would probably be unlikely.

Transferring Kanzi out wouldn't really make much sense. As you mention, she's not needed at Mogo so a transfer there isn't justified at all. Additionally, if Melbourne were to acquire some additional females, Kanzi would still be required to provide additional support and balance out the sex ratio.

It really depends on how soon Melbourne Zoo can acquire females. Holding a 1.1 troop for six months, potentially up to a year could be feasible; but any longer and it would be far from ideal from a welfare perspective.

Mogo’s troop would have been an ideal social setting for Kanzi prior to the birth of the new infant, which will make Kipenzi less receptive to any newcomers (and potentially Kisane). It’s easy to see how as an adolescent nulliparous female, she would have formed a strong bond with Kaius, the juvenile male.

Really the options are: import females within a year; bring in Mbeli (and/or Frala from Taronga); or transfer Kanzi out.

 

[Jambo]

It really depends on how soon Melbourne Zoo can acquire females. Holding a 1.1 troop for six months, potentially up to a year could be feasible; but any longer and it would be far from ideal from a welfare perspective.

Mogo’s troop would have been an ideal social setting for Kanzi prior to the birth of the new infant, which will make Kipenzi less receptive to any newcomers (and potentially Kisane). It’s easy to see how as an adolescent nulliparous female, she would have formed a strong bond with Kaius, the juvenile male.

Really the options are: import females within a year; bring in Mbeli (and/or Frala from Taronga); or transfer Kanzi out.

Considering Melbourne (and the regional as a whole) need new gorillas and new genetics I would imagine importing females would/should be the first step.

If that can't be managed they may have to resort to acquiring some of Taronga's females with Taronga then looking to be the ones to acquire new females in the long run. But hopefully, if everything proceeds to plan they'll be able to achieve the former.

 

[Tiger91]

Im not sure where this idea of transferring in a reproductive aged female from taronga is a good idea. If Kimya was contracepted because they were worried about Otana himself or how a new born would make him act.
It is a fcckin terrible idea to put one of the few reproductive females we have left with him. Transfer kanzi to taronga and transfer the two non reproductive females. Yes that's feasible. But to actually transfer a female down to such a risky male is a terrible idea. If Melbourne have gone a decade without new females because of the risk of him not accepting them, a female was put down from his antics and no new breeding was achieved because of how he may react. There is absolutely no good reason to risk it.

Melbourne either need to import new females in directly from overseas and accept that risk, or figure out what to do with Otana. If the risk of females from overseas is to risky. Why risk one of only 3 young viable breeding females with him. That is an idea that is probably one of the least intelligent I've seen mentioned on this site.

ETA: spelling/ grammar.
If the region wants to build up a population from the 3 remaining viable females. Then they need to be concentrated around silver backs that won't hinder that achievement.

 

[Zoofan15]

Im not sure where this idea of transferring in a reproductive aged female from taronga is a good idea. If Kimya was contracted because they were worried about Otana himself or how a new born would act.
It is a a fcckin terrible to put one of the few reproductive females we have left with him. Transfer kanji to taronga and transfer the two non reproductive females. Yes that feasible. But to actually transfer a female down to such a risky male is a terrible idea. If Melbourne have gone a decade without new females because of the risk of him not accepting them, a female was put down from his antics and no new breeding was achieved because of how he may react. There is absolutely no good reason to risk it.

Melbourne either need to import new females in directly from overseas, or figure out what to do with Otana. If the risk of females from overseas is to risky. Why risk one of only 3 young viable breeding females with him. That is an idea that is probably one of the least intelligent I've seen mentioned on this site.

I will just note that the prior transfer of mother raised viable females from within the region likely didn’t happen because there were none available. Frala and Mbeli have been tied up with infants in Taronga’s troop for the past decade; while Kipenzi, an infant when Otana was first imported, has contributed to the succession of Mogo’s troop and is in any case a full sister to the female Melbourne had.

Any fears around how Otana would react following the birth of a subsequent infant are merely a theory proposed on here as an explanation for why Kimya never bred. They mostly concerned how Otana would act toward an elderly female, with an incomplete social repertoire. I’d as such have no concerns about mother raised adolescent or prime aged females joining Otana’s troop.

The only alternative is to attempt to integrate Otana into a bachelor troop. It could be worth a try if they’re unwilling to import more females. Kanzi could go to Taronga; and their three adolescent males come to Melbourne to join Otana in time.

 

[Pertinax]

As a side note, it’s interesting how many silverbacks of decades past were sterile. I recall hearing their susceptibility to previously common human diseases like mumps was often the cause.

I wonder though, how many of them were really 'sterile' rather than in fact just being non-breeders? When no babies appeared did the zoos put it down to 'sterility' rather than absence of mating perhaps? There have been a few cases where regular mating occurred though and no babies, in which case true sterility was perhaps the case.

The only gorilla male I heard of that contracted mumps, which indeed may in fact have affected him, was Buluman.

 

[Pertinax]

I wouldn't have concerns about giving Otana a fresh group of normal, properly socialised females either. He's had a poor deal really with desocialised females like G anne and Julia as his group members.

 

[Jambo]

Im not sure where this idea of transferring in a reproductive aged female from taronga is a good idea. If Kimya was contracepted because they were worried about Otana himself or how a new born would make him act.
It is a fcckin terrible idea to put one of the few reproductive females we have left with him. Transfer kanzi to taronga and transfer the two non reproductive females. Yes that's feasible. But to actually transfer a female down to such a risky male is a terrible idea. If Melbourne have gone a decade without new females because of the risk of him not accepting them, a female was put down from his antics and no new breeding was achieved because of how he may react. There is absolutely no good reason to risk it.

Melbourne either need to import new females in directly from overseas and accept that risk, or figure out what to do with Otana. If the risk of females from overseas is to risky. Why risk one of only 3 young viable breeding females with him. That is an idea that is probably one of the least intelligent I've seen mentioned on this site.

ETA: spelling/ grammar.
If the region wants to build up a population from the 3 remaining viable females. Then they need to be concentrated around silver backs that won't hinder that achievement.

I do see your reasoning - put plainly you don’t see the point in risking one of the last viable females in the region with Otana.

To be fair, none of us really know the exact situation and there are a few facts at hand that we can base our assumptions on. That is that Melbourne have had the opportunity to breed/import yet haven't for some reason or another. Otana seems to be the simplest explanation for both for reasons previously stated.

I also don’t see why Taronga would be willing to offload their only viable female when they won’t likely get Kanzi in return. No breeding at Taronga will occur anyway until the young males are moved out and at the present time there’s not an obvious facility regionally that will take them on which is a slight concern.

 

[Jambo]

I wouldn't have concerns about giving Otana a fresh group of normal, properly socialised females either. He's had a poor deal really with desocialised females like G anne and Julia as his group members.

I’d like to hope so! However I have noted he isn’t the most ‘hands on’ silverback. Heck even Rigo seemed more interested in his troop from what I can remember.

I’ve rarely seen Otana approach any other members, I used to see Kimya go up to him a bit years back but that was about it. In saying that, the group did often ‘follow’ him around the exhibit as you’d expect them too.

He’s always seemed to be a bit misunderstood to me; I like to think he took a liking to Yuska. Even though she was often on the periphery, I saw her go and sit near him on a few occasions. Indeed in her later years she mellowed out; especially as she used to effectively be the ‘dominant’ female of the group from all accounts.