Is it feasible/acceptable to breed-to-cull male Gorillas?

@Zoofan15 Of course, some cases are differents and I fully agree euthanasia for healthy reasons. But a single male lion could have lived lonely. It arrives in the wild.

And to be honest : culling is used sometimes in french zoos but never revelled as too outrageous for the general public.

 

Most cases in New Zealand zoos aren’t disclosed to the public - but are sometimes mentioned in annual reports. For example, Wellington Zoo mentioned in an annual report that their dingos had been euthanised, one on medical grounds; one on welfare grounds.

The most controversial to date has been the euthanasia of four adult male Hamadryas baboons at Wellington Zoo. The public refused to understand it was necessary due to fighting amongst the baboons and an inability to place them at other zoos. Personally, I understood the reasons, but they were entirely of the zoo’s own making as they had previously exported all the females.

 

I do not know about the laws in any of the Scandinavian countries. When German media brings up the topic of euthanizing animals they always refer to Scandinavia, and within Germany you can be sure that sooner or later Nuremberg is mentioned as their zoo director is an avid supporter of it. I know that the Czech Rep has pretty lax laws regarding this topic, but this is not brought up as they have never been mentioned in the public Also, I am far from saying that there is only one right view on this topic

Well, of course euthanizing is an option in singular cases. I don't agree to this particular example though, it's not necessarily a problem for a lion to live alone, especially for an old one. Why not waiting and checking on how she behaves after the death of the other one?

 

Could moderators please change the thread title? EAZA never proposed to cull gorillas. And it is better not to encourage clickbait / sensationalist titles.

Concerning gorillas, I think Gelada EEP has much more sensible stance. They recognize that aggression and infanticide are natural behaviors, and that keepers attempts to 'fix' them don't consistently result in better welfare.

My solution would be redesigning group exhibits with more internal sight barriers, to reduce tension and allow juvenile males to stay longer in the natal group, reducing the time when they are alone. Grass lawns with few wooden frames should go. Second, rebuilding exhibits to keep males next to breeding groups (possibly their natal ones), allowing both interaction through the gates and withdrawing. This would model the real social structure of gorillas, where bachelor males regularly interact with groups. Third, keep more bachelor groups, and redesign them to be able to keep several males in separate sub-exhibits with voluntary visual contact. Maybe old and influential zoos which insist on keeping gorillas, but have objectively small exhibits stitched from several even smaller old rooms, should switch to bachelor groups, and give breeding groups to larger exhibits? Fourth, rotate males in groups more often, even at the cost of stopping breeding and disturbance to females. This would mimic the natural response of gorilla population to high population size, where social tension rises and breeding slows.

And I feel that some people project Western ideals or human ethics to gorillas. Objectively, there are natural and unnatural behaviors, and natural or unnatural frequency of behaviors, but there is no 'good' or 'bad' animal behaviors. Aggression of gorillas is as natural as affiliation, and killing as natural as conception. Trying to eliminate gorilla aggression is projecting human values, the same as calling carnivore animals villains. One should be concerned if aggression of zoo gorillas was higher than wild gorillas, but zoo gorillas live with unnaturally low or no fighting.

Second, both from the view of science and view of welfare, no sex or age class is less desirable than another. Young males are as worthy as old females and any others. Word 'surplus' males belongs to livestock husbandry, where the goal is maximizing production of young. But gorilla EEP no longer needs to maximize breeding.

 

Unfortunately in many cases zoos sill shy away from having male groups, I could name you one that was asked to split their group into a family and a bachelor group but they rejected it although the enclosure would have allowed it with ease, it wouldn't even have caused building costs. A fifth solution that IMO is not done enough in zoos and would keep the breeding rate lower (applies to other species as well) is to castrate males as e.g. Stuttgart, Cologne and Duisburg have done.

 

Zoos who participate in EEP programs are following several targets, including keeping selfsustaining population numbers at sufficient level and the most important - conserving as much genetical diversity inside the captive population as possible. Holding space in Europe is finite and with growing space demand per individual, it might decrease in future. If 1/3 of available capacity of a harem-living species is blocked by males that are not needed for breeding at all (and would be probably already dead in the wildness), it decreases effective size of the population. This is negative.

 

This same suggestion was brought up with Asian elephants but discarded for the same reasons the gorilla proposal was. I think it's very valid to be concerned of public opinion. They buy the tickets, the souvenirs, the food, they provide the income. Their opinion matters (unfortunately, in many cases...)

I don't think culling animals is "barbaric" as has been suggested here before. I believe it can be a humane and stress-free solution to the problem. Even easier than if that animal was experiencing a natural death, say of old age related causes. I also believe the byproduct of culling could (and should) be used as an educational tool and contributed to scientific and veterinary understanding of the animals. Marius was brought up in this thread as a negative example, but I find that case to be a positive one where the animal was utilized in an educational presentation for the public. That kind of opportunity is very rare. I'll never forget the killer whale necropsy (of a wild animal that died) that I was able to watch live -- that can be a defining moment for the right kid with the right passions and interests.

Absolutely the animals should be bred responsibly to avoid "surplus" stock in the first place, but populations change over time (particularly with such long-lived animals), and the importance of maintaining a healthy and stable age pyramid within the breeding population can't be understated.

Perhaps going forward a reliance on sex-selected AI could be implemented. I'm sure there are other solutions, including the establishment of additional gorilla holding facilities to expand the overall capacity.

 

This would be true for a rarer species. But zoo gorilla population is large (>800 in EAZA + AZA, and new zoos interested) and generation length is long, so a lower effective population will still be sustainable, theoretically perhaps for >200 years of zoo breeding.

And non-breeding adult male gorillas are actually the most attractive displays. They are the iconic huge beastly apes which attract the paying public. Zoos should want them, perhaps often prefer them to breeding groups.

It is a bit of a fashion in zoo circles to have a breeding group. But it is no longer special to breed gorillas. A zoo can participate in saving gorillas by keeping non-breeding ones and e.g. raising funds for wild reserves. 50 years ago zoos had the opposite fashion - they preferred just 2 or 3 individuals for display. Big breeding groups were seen as lack of financial prudence - cost more but don't bring proportionally more visitors.

 

Actually zoos were looking to breed them at the time, and there was huge kudos for any zoo that did. They just had no idea that a correctly balanced social group was required. They thought a couple, just like humans, would be fine. I remember lack of breeding being blamed on "incompatibility", films of gorillas mating being shown as after hours entertainment to get them in the mood, and of course AI. Once gorillas started to be kept in correctly structured social groups, breeding flourished. There is a lesson here - animals will breed successfully so long as we provide them with the conditions they need, not what we assume is best. Failure to breed a species successfully in captivity is our fault not theirs.

 

Aren't I correct in thinking at one stage around the 1990's, Taronga did say they would cease gorilla breeding until some form of sex selection became scientifically possible. But then they didn't adhere to this and have had further (regulated) births since- which have unfortunately continued to have a male bias?

 

The major problem until the 1970's was that so many young pairs were imported from the wild as babies and then grew up together, developing a platonic or sibling relationship where over-familiarity inhibited or much reduced mating behaviour, or alternatively they had to be seperated due to the male's aggression. Once zoos realised this and breeding transfers/
addition of unfamiliar females starting being practised, the problem was cracked.

 

In the meantime, EAZA itself has responded with a statement.
https://www.eaza.net/assets/Uploads/2021-11-24-Press-statement-gorillas4.pdf

 

Besides the main topic, the statement has an interesting quote: ' EAZA zoos that have provided €12,591,891 and close to 8,000
staff hours to in situ conservation projects for gorilla and other great apes in the past five years'.

I feel zoos should make a list of money they provide to wild conservation and publicize it more. Any anti-zoo organization criticizing keeping some animals should be immediately responded: zoos raised XXX€ for wild animals of this species, which would not happen if there were no education animals in zoos, could you please match this sum? Since the main purpose of anti-zoo lobbyists is getting money for themselves by parasitizing on popularity of zoos, this should be a very effective statement - even if other arguments for zoos are objectively more valid.

 

That’s news to me, but might explain the pause they had in breeding.

After arriving from Apenheul in 1996, Frala gave birth to two non surviving infants in 1998 and 1999. There was then a four year delay until she and Mouila produced infants in 2003. This was the largest gap between surviving infants (1996-2003) the troop had ever had.

Kibabu’s troop produced 4.2 infants between 2003 and 2008; Kibale’s troop has produced 3.1 infants since 2014.

 

I am pretty sure remembering an announcement at that time. It seems they were trying to find a solution to the problem even back then.