Gorilla Casteration

[Leptonyx]

What we are looking for is exactly a reduction in the hormones produced. To make the Silverback a less threating agressive animal.

Intersting path though

Ohhh...my mistake! I thought we were just looking for ANY alternatives to castration. Although on that note- chemical castration would definetely lower silverback agressiveness/libido- unfortunately it's also coupled with depression and weight gain...

 

[zooman]

Indeed, it has been reported in mountain gorillas so far; and in my opinion, this does "justify" the foundation of bachelor gorilla groups in captivity. If it works with mountain gorillas in the wild, why not with captive lowlands? The existing zoo bachelor groups seem to support this assumption.QUOTE]

Hi Sun, you know what l wish l had your ability to comunicate in the written word that you do. As you present a very interesting and informative point.

It's just that l think you are completely wrong in a couple of points. Most importantly "If it works with mountain gorillas in the wild, why not with captive lowlands" Firstly l not convinced that there are wild bachealor groups of lowland gorillas. An example of 1 mountain gorilla group is not convincing. Also variables are obviously huge in captivity. Most importantly that males are free to move in and out of said group in the wild. Far from a reality in captivity.

"The existing zoo bachelor groups seem to support this assumption." The only to my knowledge trully working long term result is achieved when the gorillas are placed together at a very early age. Something that is just not becoming zpp practice.

Once again though wish l could write like you do.

PS are you a zoochat supporter?

 

[zooman]

Ohhh...my mistake! I thought we were just looking for ANY alternatives to castration. Although on that note- chemical castration would definetely lower silverback agressiveness/libido- unfortunately it's also coupled with depression and weight gain...

Hi, mmmm not so sure a soloution if we end up with a whole lot of depressed overweight silverbaks. Can you just picture them

Shame about that though chemical castration sounded good for a momment.

Tell me what are you studying?

 

[Steve Robinson]

This is a tangent- but the above mentality is also the reason why 9.6 million cats and dogs are euthanized in the States due to overbreeding. I realize the ethical debate that surrounds castration, but I do believe it has it's place in certain animals...a necessary evil unfortunately, until things get under control again.

As to the gorilla castration...how about a vasectomy? Essentially the same as castration, only the side effects are less pronounced as the same hormones are still being produced. I also looked into chemical castration...it has it's negative side effects, but it is reversible. In either case, both methods used in humans, so it would fit nicely with the ethical concerns on this board.

Yes, it was a bit of a [light -hearted] tangent and you are quite right - castration is a legitimate husbandry tool to control gender imbalance problems in captive populations. Better, surely, than another equally legitimate tool - euthanasia?

However - why not vasectomy? It won't solve the testosterone problems of course, but in groups isolated from cycling females, is that going to be a problem with gorillas?

 

[black_wreath]

Hi matey, interesting question as it would seem a stupid thing to do!
In the early 80"s l challenged the Bristol Zoo. As to why they would put there female gorillas onto a contraceptive!

Then l was told.
1/ There was a shortage of suitable zoo's with enclosures that were adequate to house more gorillas.
2/ that they did not want some of the females mating with a close relative.
3/ There were too many male gorillas being born and that they were a problem when mature. As they would then require there own group or they would live in isolation. Something a highly intelligent sociable animal is not meant to do!!

Nothing has changed in 25 years!

What has evolved from the experience of Atlanta zoo and Howlettes. Is that male gorillas will live together for periods of time. Just not indefinatley, and often for short periods of 1-2 years. Also it is a huge problem when the male reaches sexual maturity and becomes a silverback.

To move a Silverback gorilla from 1 group to another is a very difficult procedure given there highly evolved social structure.Apenhaul zoo in the Netherlands has spent at least 9 months gradually introducing there new silverback to the group.

To move a Silverback from a 1 all male group to another all male group. Does not always work with success at all and can be very expensive and time consuming.

The most successful arrangement to date is at Atlanta where the males were put together at a very young age and have grown up together. Atlanta zoo was very sure that the blood line of these gorillas was already very exposed in the captive population of Gorillas specifically North America.

So in 2008 we have a surplus of male gorillas in captivity. Exactly what Bristol said would happen when l spoke with them. It's only going to get worse. I would say in 5-10 years time the problem will be huge.

The castration of a gorilla seems like a feasible option to me. Certainly not what l would suggest in a perfect world but this is not a perfect world!

The only experience l have with an animal that has been castrated is. Horses and dogs which l have had most of my life. They seem to adjust well.

PS your picture are great!

Does anyone know if there is a gorilla semen bank somewhere? I'm pretty sure some zoos do it for their critically endangered animals where they can't ship the individual to other zoos to breed. So hypothetically- if there was a gorilla semen bank...we could castrate them without fear of losing their lineages....?

...That all seems very obvious now, I withdraw my embarrasingly stupid question lol...

Thanks.

 

[Pertinax]

Evidence for Wild bachelor groups. Sun Wukong says 'if it works with Mountain Gorillas in the wild, why not with captive Lowland Gorillas?' But that's assuming Mountain gorillas DO have bachelor male groups and I don't think there is ANY evidence for this apart from that one (unusual?) situation in Dian Fossey's Mountain Gorilla study group 5(which originally included at least one female so perhaps the males leftover were a relict of a normal male/female group.) So its interesting that in the absence of any other evidence, the phenomenum of male groups in captivity may well have stemmed from that one example and may be therefore largely based on fallacy rather than fact. No one in this discussion so far has come forward to dispute or document any other evidence for wild male groups in either of the Gorilla species. I would very much like to hear of any.... Natural or not, it has to be agreed that (fortunately) this type of grouping certainly works with younger male Gorillas in captivity and with some silverbacks too(but not all) seemingly depending on temperament and individual situations.

Castration versus vasectomy- vasectomy will not reduce normal sexual drive/aggressive instincts, the silverback would remain normal in everything except fertility. Castration may seem an extreme solution but like it or not, while captive gorillas continue breeding and producing 50% male offspring, it may prove to be the easiest/only option for some of the most overrepresented young males. Apenheul who are nowadays responsible for the EEP Gorilla programme have been the instigators for both the castrations done- many years apart- so far (Kukuma & Loango both being born there) and as Yassa said, its likely they will promote this method in the future.

 

[Sun Wukong]

Gosh, I must have had hit a nerve there-as that innocent little post of mine has been quoted at least twice...
Seriously:
@Pertinax:
Are you sure that it was just a single case in the mountain gorillas? I remember discussing this very topic with some quite versed folks a few years ago; one of them sent me an interesting link where several cases of wild bachelor grouping in Mountain Gorillas were mentioned. Unfortunately, I deleted that link after reading; maybe I will stumble upon it again or happen to meet that guy and ask him. In any case, I will post it here, as I assume that you're not the only one in this forum interested to read more about this topic.

I don't think that forming bachelor gorilla groups in zoos-may it be in the US or Tenerife-was highly influenced by observations in the wild; I rather assume it was a "trial-and-error" experiment, born out of sheer necessity.
@zooman: Well, thanks for the compliment.
However, I-naturally-don't see myself being wrong in that many points. The observation of this behaviour in the wild and the more or less successful bachelor groups in zoos seem to go along with each other; maybe future observations in the wild and additional husbandry experience will prove whether my assumption here was premature and wrong-or correct. In regard to then not-castrated males-let's hope for the second.


http://www.aza.org/AZAPublications/2006Proceedings/Documents/2006RegMtg1.pdf
http://www.aza.org/AZAPublications/2006Proceedings/Documents/2006RegMtg2.pdf

 

[Pertinax]

Seriously:
@Pertinax:
Are you sure that it was just a single case in the mountain gorillas? I remember discussing this very topic with some quite versed folks a few years ago; one of them sent me an interesting link where several cases of wild bachelor grouping in Mountain Gorillas were mentioned. The observation of this behaviour in the wild and the more or less successful bachelor groups in zoos seem to go along with each other; maybe future observations in the wild and additional husbandry experience will prove whether my assumption here was premature and wrong-or correct.

I don't see it as a case of hitting a nerve, more a case of trying to unravel the facts from the fiction. I for one would be really interested to know of other indisputable evidence for wild bachelor groups- I don't understand why I've never come across any in everything I've read- but that's not to say it isn't there.

I believe the initial idea of forming bachelor groups WAS taken from the presumption that they do this in the wild. When it worked initially with mixed age groups of animals at St Louis and Loro Parc (and Port Lympne), it seemed to bear out the theory too. Only later when some(I agree not all) Silverbacks started fighting and partnerships had to be broken up did some institutions realise keeping males in this way wasn't going to be all 'plain sailing'. To quote the keeper at Paignton when the two initial silverbacks of their nascent bachelor group had to be split up(after growing up from juveniles together in Cologne Zoo in Germany) ' Basically Klaus just wanted to kill him' (Pertinax, the 2nd male.) Doesn't sound too harmonious does it?

Anyway, if anyone can find me some more bachelor group data/evidence for any gorilla population I would be interested. I do know that recent researchers studying wild Lowland gorillas have reported 'No evidence of males grouping together' and 'adult males without harems live solitary and seem to avoid interactions with each other' which seems fairly clearcut evidence to the contrary to me.

Incidentally, I'm not particularly pro-castration for Gorillas either- if Belfast's Kukuma is anything to go by it produces a sorry looking creature- but it may still be a necessary evil, so to speak.

 

[Leptonyx]

Yes, it was a bit of a [light -hearted] tangent

Hehe- completely I was merely expressing my disdain for people who use the phrase as a scape-goat rather than responsible pet ownership. Otherwise I'm completely in agreement of the golden rule of treating others as you would yourself I guess the whole "castration vs. euthanasia" all depends on who you ask...at least...for the friends in my group...haha.

Hi, mmmm not so sure a soloution if we end up with a whole lot of depressed overweight silverbaks. Can you just picture them

Shame about that though chemical castration sounded good for a momment.

Tell me what are you studying?

Mmmm..not sure if I really want to. Although our male "Charles" looks rather grumpy most of the time anyways...hehe. I just graduated this summer from university with a Bachelors in Zoology, and I'm doing my masters now looking at the impact of human development on reproduction of wild waterfowl I'd heard of chemical castration being done before- but I believe it was as a form of control for rapists/agressive re-offenders to keep their hormones down. However it is reversible- so once you take them off the medication they're back to their old selves...so perhaps a rotation of meds on and off would help? In either case- the issue of space will probably hit before we come up with a viable solution to save all the males

 

[Leptonyx]

"immunocastration is seen as a means of controlling testosterone-dependent behaviour (libido and aggression) in a way that does not result in a permanent loss of breeding potential, does not carry the risks of surgery and does not infringe regulations with respect to pharmacological treatment."

Veterinary Sciences Tomorrow

Veterinarians inject a vaccine which will basically make the body create anti-bodies against it's own hormones, sterilizing itself. At least in boars, bulls, and stallions, it has been shown to reduce agressive behaviours. It only requires one or two injections, with it's effects lasting roughly 3.5 months. It's being investigated for use on farms, so I'd imagine it would be easily cost-effective. It's also reversible.

 

[Sun Wukong]

Don't celebrate too prematurely; these procedures are still in an experimental stage and their acceptability in each species and individual is still highly debated. Similar experiments in humans (for example with sexual offenders) didn't have the desired results and showed several adverse reactions.
Additionally, finding a company producing such treatment for gorillas for an affordable price to use on a wider spectrum is going to be tricky, too...

 

[Leptonyx]

True...BUT....

Sun Wukong, just wondering where/when immunocastration was ever performed on a human? I agree it's a recent procedure in which the kinks still have to be figured out- but compared to other techniques discussed at least it is the more *ethically* acceptable choice.

To add to your comments, the argument goes that studies done on pigs/stallions/bulls can be quite applicable to other species because the same hormone is present in all reproducing mammals (GnRH). Of course nothing ever turns out as it lays out in the textbook , but there is some basis in doing these procedures on other mammals first, which have shown promising results.

The cost shouldn't be an issue really- the reason immunocastration is being investigated so thoroughly is because agriculture hopes to limit the occurance of a hormone-induced diseases (ex., boar taint) in pigs that go to market. So if a farm can afford immunocastration vaccines for all the pigs it sends to markets...it shouldn't be that hard for a zoo with valuable animals to afford either Just some friendly comments to add- but feedback is always appreciated

 

[Al]

Kukuma at belfast is a well adjusted member of our gorilla group. He may not be as impressive as a adult silverbak but non the less I think he is still a striking animal. I believe a life in a social group is far more important than leaving animals intact and solitary. I believe there has been some work in the states on gorilla semen and there are plans to AI using sex selected semen. This although not completely successful so far may be an increasingly practiced procedure in the future.

 

[Sun Wukong]

@Leptonyx: GnRH is also present and working in gorillas-yet the receptors, their numbers and sensibility differ from species to species-thus also prompting to the production of different vaccines. Additionally, rather negative side effects have been observed, depending on the species:

In a pilot study conducted at Utrecht University, eight out of 12 ferrets immunized against Gn-RH became lethargic and anorectic after subcutaneous vaccination. Long-term supportive care did not result in any improvement, and the eight affected animals had to be euthanized (Schoemaker NJ, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands: Unpublished data, 1998). Postmortem examination disclosed nonspecific lymphocytic-plasmacytic infiltrations in multiple organs (liver, kidney, lung, and intestines), suggesting a nonspecific immune reaction. In the same experiment, 24 control ferrets were used (12 surgically neutered and 12 intact). Since these ferrets had not received any component of the Gn-RH vaccine, had been kept in the same area, and had not shown any signs of disease during the vaccination trial, it is assumed that a component of the vaccine was responsible for the nonspecific immune reactions. To confirm this assumption, further studies are necessary. Such a vaccine should not be used before the cause of these reactions has been unraveled. So much about a basis...
Current and future alternatives to surgical neutering in ferrets to prevent hyperadrenocorticism - Veterinary Medicine

Reg. sex offenders:
Grossman LS, Martis B, Fichtner CG. Are sex offenders treatable? A research overview. Psychiatr Serv 1999;50:349-361.

Boar taint is not a disease; it's a normal characteristic of the not or too lately neutered male pig (and its meat), unwanted by human consumers. Veneric diseases hardly ever occur nowadays in modern commercial animal "production" due to vast employ of AI. Mentioned techniques rather aim to get a more productive sex ratio in regard to the intended use (i.e. more cows for milk production).

Compare numbers of pigs and cattle commercially raised and kept worldwide to that of surplus male lowland gorillas in zoos; and now start to think why companies are more likely to invest in mass-producing such methods for domestic animals (not to mention the pet market) than specifically for a handful of zoo animals. For many zoos, costs ARE an issue. If it's cheaper to neuter a surplus male, send him to another institution or even kill him, most zoos will rather choose one of these options than a very costly (as specifically made) and not yet tested one. Hope that's the feedback you wanted.

 

[Pertinax]

Kukuma at belfast is a well adjusted member of our gorilla group. He may not be as impressive as a adult silverbak but non the less I think he is still a striking animal. I believe a life in a social group is far more important than leaving animals intact and solitary. I believe there has been some work in the states on gorilla semen and there are plans to AI using sex selected semen. This although not completely successful so far may be an increasingly practiced procedure in the future.

I haven't actually seen Kukuma- only photos. Is he as large as a normal male or nearer female sized?

I agree about the social life part. You are also right about the sex selection work and I think this may well come into play in the future. But it still leaves the current problem with so many young surplus males around.

 

[Pertinax]

Mountain gorilla bachelor groups.

Further to my original posts, the only evidence I can find relates to Dian Fossey's study Group 8 (not 5 as I previously stated). It contained a Silverback(Rafiki) four younger males and a very old female(Coco) Dian Fossey surmised that the female was the mother of two of the younger males, and by facial likeness that the other pair were also related, possibly the offspring of another(deceased) female and that the 4 younger males were all fathered by the old silverback Rafiki. As such the four younger males were still living in their natal group. They had NOT come together from other groups.

After the old female died, the males started to become more restive and two left the group together. The old male continued to squabble with the eldest remaining son(Samson) and after his father acquired new females, this son left too but later came back and abducted a female from his own father. (The youngest male remained longer with his father and single mate before finally leaving to 'travel alone' in search of females.).

I can't see any male cohesion in all this - more a mirror of what happens in some captive male groups. I'm still looking for further evidence though.

 

[Leptonyx]

Compare numbers of pigs and cattle commercially raised and kept worldwide to that of surplus male lowland gorillas in zoos; and now start to think why companies are more likely to invest in mass-producing such methods for domestic animals (not to mention the pet market) than specifically for a handful of zoo animals. For many zoos, costs ARE an issue. If it's cheaper to neuter a surplus male, send him to another institution or even kill him, most zoos will rather choose one of these options than a very costly (as specifically made) and not yet tested one. Hope that's the feedback you wanted.

@ Sun Wukong- Most definetely the feedback I wanted As long as I'm learning something- it's all good! As to the comments of cost, I wonder if any private NGOs would be willing to fund a project looking into immunocastration? Maybe some animal welfare advocates? I'm not ready to give up on a complete alternative to castration yet

I'll have to read the article you posted and get back to you later on once this crazy week of school is over, AND get back to you on the subject of "species specific" drugs/injections...at least in my experience, I'm pretty sure there are a couple of exceptions to that as well! Hope your week goes better than mine...

 

[Sun Wukong]

"I wonder if any private NGOs would be willing to fund (...)" I have friends who hardly do anything else but being on the knocker to find sponsors for noble causes. It's not that easy. Besides: why just gorillas? The problem runs much deeper-including less "attractive" species like ungulates or various species of reptiles.

Many if not most of the "animal welfare advocates" would rather see the zoo closed than help financially...

So far, my week has been rather lousy, too...

 

[Leptonyx]

Ahhh phooey. I read the article to procrastinate from studying (hoping to find a loop-hole ) and no luck. Darn. The one source I had where immunocastration was deemed acceptable had fine print which I didn't catch either...oh well...guess the guy gorillas will have to lose em

HOWEVER...I was discussing this topic with my co-worker the other day- and she suggested IVP (in-vitro production). You can determine the sex of the offspring, and it's supposedly more effective than AI (haven't been able to look this up personally yet). It's worked in rhesus macaques, and in humans too. So if this were to work- we would at least be able to limit the number of male gorillas entering the world. That's my last suggestion- I promise!

**On an interesting sidenote- I didn’t know that “neutering” was attributed to both male AND female…we’ve been using the term “spay” for the females castrations done at the vet clinic for as long as I can remember!**

 

[Leptonyx]

Actually- I was thinking gorillas might be easier to find sponsors for...they're definetely one of the more popular animals, and everyone seems to empathize and appreciate gorillas more than the other animals (this whole thread just proves it )

Although I agree it'll become more complicated once you try moving away it'll become more difficult. Annd...as an afterthought...maybe we'll leave the animal welfare advocates out of this..haha. Hope your week goes better! Back to work