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

[Zoofan15]

EAZA Proposal to Cull Adult Male Gorillas

Campaigners criticise European zoo proposals to cull adult male gorillas

Overcrowding of critically endangered Western lowland gorillas in zoos has led the influential European Association of Zoos and Aquaria (Eaza) to consider killing adult males of the species.

Leaked documents seen by the Guardian reveal that culling, castration and keeping adult single males in solitary confinement for a large portion of their lives are seen as potential solutions to an overpopulation of the species in zoos. The gorilla population in Eaza zoos consists of 463 individuals (212 males, 250 females and one of unknown sex) at 69 institutions.

The gorilla action plan, released to stakeholders in zoos, admits that culling would be “the most appropriate tool if strictly talking from the biological point of view,” but that the decision could be unpopular with the public.

Click link to read full article.

 

[Daniel Funk]

Here's an article from the German newspaper Der Spiegel.

Zoos wollen Gorillas töten

 

[Zoofan15]

Damian Aspinall is promoting rewilding them. Surely he realises the implications of releasing dozens of lone males into the wild...

A alternative to culling them could be to retire several of them off to non accredited zoos/wildlife parks that prove they can provide for their welfare and husbandry needs.

 

[Coelacanth18]

Leaked documents seen by the Guardian reveal that culling, castration and keeping adult single males in solitary confinement for a large portion of their lives are seen as potential solutions to an overpopulation of the species in zoos.

Doe anyone know if using birth control has been considered as a potential solution? Contraception is one of the primary methods used in the U.S. for managing population growth, and it's particularly common with great apes since they can use human birth control pills. I know that many continental European zoos have a different perspective on that when it comes to welfare, but I'm curious if the subject even came up or was being considered - I couldn't find it mentioned anywhere in that Guardian article at least.

 

[Jana]

Doe anyone know if using birth control has been considered as a potential solution? Contraception is one of the primary methods used in the U.S. for managing population growth, and it's particularly common with great apes since they can use human birth control pills. I know that many continental European zoos have a different perspective on that when it comes to welfare, but I'm curious if the subject even came up or was being considered - I couldn't find it mentioned anywhere in that Guardian article at least.

Contraception is used by European zoos for gorillas for decades, of course.

 

[Yassa]

Most female gorillas in European zoos are on the pill. Many zoos havnt had a birth in many years. So of course contraception is used, almost everywhere!
But limiting the numbers of babys doesnt change the sex ratio.

The idea of Damian Aspinall is ridiculous. Having too many adult, lone male gorillas in one area results in aggressive attacks of these lone males against family groups, meaning injuries and deaths, especially for infants. Plus Damian forgets that in the wild, male gorillas have a much higher death rate than females. In addition to that the death rate of gorillas put back in the wild is high. I would really like to know how many of the 70+ gorillas he sent back to Africa are still alive today, and how many of they are males.

 

[HungarianBison]

Major Hungarian online journal Telex citates Damian Aspinall about the issueTúl sok nyugati síkvidéki gorilla él az európai állatkertekben, felmerült, hogy leölik a felnőtt hímek egy részét
In my opinion this decision of the EAZA helps vegans and other anti-zoo people to continue their propaganda against zoos.
I know that this issue is quite complex because afaik there are a few behaviour and aggression problems in the majority of bachelor groups, but killing endangered animals never can be a solution.

 

[Yassa]

As far as I understand NO ONE in the EAZA is recommending/ instructing zoos to kill male gorillas. They said it would be the most appropriate tool from a biological point of view, but also has many disadvantages.

 

[Zoofan15]

Doe anyone know if using birth control has been considered as a potential solution? Contraception is one of the primary methods used in the U.S. for managing population growth, and it's particularly common with great apes since they can use human birth control pills. I know that many continental European zoos have a different perspective on that when it comes to welfare, but I'm curious if the subject even came up or was being considered - I couldn't find it mentioned anywhere in that Guardian article at least.

Several zoos in Europe use contraceptive pills and the last infant at Prague was castrated, which has been done at other European zoos. Contraception is even stricter in Australasian zoos with some females having gaps of six to ten years between offspring.

Contraception is a good method of controlling population growth, but it’s a double edged sword when you consider the benefits young gorillas gain from observing the raising of infants.

 

[Coelacanth18]

But limiting the numbers of babys doesnt change the sex ratio.

That's true, but the problem cited isn't the sex ratio - it's overpopulation. If the problem is that there are too many males specifically, that's a different issue than there just being too many gorillas generally. I believe the US has dealt with a problem of surplus males by several zoos holding bachelor troops - either as the only troop at the zoo or in a renovated space that has enclosures for multiple groups. I think it's interesting that the article noted this: "Once male gorillas reach a certain age, zoos do not keep them in all-male groups, because of the risk of violence." I wasn't aware of that and perhaps it's true, but there are certainly a good number of bachelor troops over here.

In my opinion this decision of the EAZA helps vegans and other anti-zoo people to continue their propaganda against zoos.

Just saying "anti-zoo people" is probably the best way to phrase this, given that not all vegans - perhaps not even a majority of vegans - are anti-zoo. The two are often correlated, but people can be vegans for lots of reasons that have nothing to do with animal rights.

I know that this issue is quite complex because afaik there are a few behaviour and aggression problems in the majority of bachelor groups, but killing endangered animals never can be a solution.

While I don't know whether I agree with these solutions or not - I'd need more information to feel secure in making a judgement one way or another - I wouldn't necessarily agree that killing endangered species can *never* be a solution. Unless you're against killing all animals generally, there are arguments that can be made for culling even endangered species if there are no good alternatives and the endangered species are a problem for their area - for example, overpopulating a particular park with no good place to move them.

Contraception is a good method of controlling population growth, but it’s a double edged sword when you consider the benefits young gorillas gain from observing the raising of infants.

It is, and I'm open to arguments against using contraception like that one - I was just curious about the fact that it wasn't mentioned alongside the other options, all of which also involve potential downsides.

 

[Zoofan15]

I believe the US has dealt with a problem of surplus males by several zoos holding bachelor troops - either as the only troop at the zoo or in a renovated space that has enclosures for multiple groups. I think it's interesting that the article noted this: "Once male gorillas reach a certain age, zoos do not keep them in all-male groups, because of the risk of violence." I wasn't aware of that and perhaps it's true, but there are certainly a good number of bachelor troops over here.

We’ve to date had two bachelor troops in Australasia:

Werribee Open Range Zoo:

1.0 Motaba (23/12/1983) Jambo x Nandi; Imported 1990
1.0 Yakini (28/11/1999) Motoba x Yuska
1.0 Ganyeka (29/04/2000) Motoba x G-Ann

Orana Wildlife Park:

1.0 Fataki (24/05/2003) Kibabu x Frala
1.0 Fuzu (08/12/2007) Kibabu x Frala
1.0 Mahali (18/08/2008) Kibabu x Mouila DECEASED

Both have existed for years without issue. The previous alpha of the older troop (Motoba) was displaced as alpha by his son with minimal conflict a few years ago.

There’s also successful bachelor troops in Europe.

 

[Yassa]

Honestly, there are very few ‚sucsessful‘ bachelor groups in Europe. All-male groups work well as long as there is only one adult male, but as soon as all members mature, there is usually a lot of agression. It happens often that one male needs to leave the group permanently, and even if levels of aggression seem tolerable, there is often no positive interaction between the males, just aggression or at best ignoring each other. That is not a good situation for social animals.

I am sure all-male groups in the US have the same problems, maybe they just hide it better. And I would really like to talk with a keeper from Werribee and Orana to learn if their groups really work this well or if the problems are just not known by the public.

 

[Pongo]

Many EAZA programs have implied a management plan in the meantime, in which e.g. they analyze the maximum of individuals that can be kept of a species given the current number of holders. The problem is that in the past most zoos were breeding and breeding and as long as they somehow got rid off the offspring they kept doing it - after all it's still the cheapest and most attractive advertising to show little babies. But there was no real plan behind and now after analyzing they realise that for many species need to imply a breeding stop to lower the number of animals. This of course is a problem mainly with animals who live pretty long.

The issue EAZA faces is that there is no general EU law about such matters. In Scandinavia it's probably pretty easy to cull, in Eastern Europe probably, too. In Germany culling an ape or a big cat and many other species is considered a criminal action, also for zoos. I am pretty sure that this is similar in the Netherlands where they are pretty strict with animal rights.

 

[Pertinax]

There’s also successful bachelor troops in Europe.

As Yassa mentioned, they work okay while the animals are younger, but as they mature there is more fighting and tension, frequently to the extent where seperation becomes necessary. In some of the oldest groups, e.g at Port Lympne, Paignton and Loro Parc, at least one male has been permanently seperated and lives solitary for many years now- (two males out of a group of five do this at Port Lympne). New groups are still being formed however, nowadays using a single silverback with several younger males, related if possible but often not. Again, this works until all the animals are mature, when the aggression often starts. More recently EAZA have sent surplus males to form new groups in places like the Middle East and India also.

I think both the Australasian groups are so small they may have largely avoided these problems- one being three related animals(father/sons) and the other only two animals- both factors that may help, though like Yassa I wonder if there are underlying stresses that go unmentioned.

 

[Opieone86]

In Scandinavia it's probably pretty easy to cull

Who says it is easy for people in Scandinavia to kill animals?
it's never easy, and never has been.
After the giraffe marius was killed, people may have thought we were indifferent, which does not fit at all.
We do care a lot about animal welfare and that animals are treated properly.
We are not barbarians

 

[Zoofan15]

Who says it is easy for people in Scandinavia to kill animals?
it's never easy, and never has been.
After the giraffe marius was killed, people may have thought we were indifferent, which does not fit at all.
We do care a lot about animal welfare and that animals are treated properly.
We are not barbarians

I believe @Pongo was meaning that euthanasia for management reasons is an option in Scandinavian countries as opposed to countries where it’s outlawed unless for medical reasons. I have no doubt the general public there were as outraged as other people across the world by Marius’ death.

Euthanasia in Australasian zoos has often been carried out for management reasons and most of us on ZooChat accept it happens and the reasons why it’s undertaken.

 

[MRJ]

Seems to me the long-term answer may be sex-selective abortion.

But things have come a long way from the time of my childhood, when the birth of a gorilla in captivity was seen as an amazing thing.

 

[Zoofan15]

Seems to me the long-term answer may be sex-selective abortion.

But things have come a long way from the time of my childhood, when the birth of a gorilla in captivity was seen as an amazing thing.

That’s a good point. I was only thinking the other day of an article I found from Taronga’s history about one of their gorillas. In 1999, Frala was pregnant with her fifth infant which testing had identified was a female. The zoo denied the infant would have been aborted if it were male - and indeed welcomed 4.2 infants into their troop in the 2000’s proving that wasn’t their management practice; but 22 years on, perhaps this could be implemented more in zoos?

 

[Antoine]

I believe @Pongo
Euthanasia in Australasian zoos has often been carried out for management reasons and most of us on ZooChat accept it happens and the reasons why it’s undertaken.

You are probably true but I have to say that I will never agree with this type of management and maybe have to fight against zoos if they want to generalize this. I think we have a duty to animals as we are responsible of their disappearance : that's the major reason we say zoos must still opened and why we accept the animals are captive. Now, because zoos do wrong for decades animals must be killed for management reasons. Well, if so, zoos failled their missions and must close.

Sorry for this message but I think it was important for me to give my personal feelings.

 

[Zoofan15]

You are probably true but I have to say that I will never agree with this type of management and maybe have to fight against zoos if they want to generalize this. I think we have a duty to animals as we are responsible of their disappearance : that's the major reason we say zoos must still opened and why we accept the animals are captive. Now, because zoos do wrong for decades animals must be killed for management reasons. Well, if so, zoos failled their missions and must close.

Sorry for this message but I think it was important for me to give my personal feelings.

No apologies necessary. I agree it’s sad when animals are euthanised due to a lack of planning; but support decisions such as Auckland’s to euthanise their two elderly lions together (when one needed to be euthanised on medical grounds), as to not do so would lead to suffering from a welfare perspective (being social animals).