Genetic diversity and zoo conservation

I'm curious, just how many genetically distinct individuals need to be present in a population for you to consider them healthy enough? It can be tough to imagine all the lemurs present today descended from only one female or one family group, but can you positively say that several hundred (if not more by your definitions) completely distinct founders made their way to the island within a generation or two?

~Thylo
I'm talking about geological time here. Within tens of thousands of years, how many rafts leave South America, into the Caribbean? With animals on board? (Hint: its several times a calendar year.) Would've been the same for Madagascar when the variables were optimal on the mainland. And how long would it take for lemurs to lose interfertility with mainland relatives? Not just a generation or two.
 
I'm talking about geological time here. Within tens of thousands of years, how many rafts leave South America, into the Caribbean? With animals on board? (Hint: its several times a calendar year.) Would've been the same for Madagascar when the variables were optimal on the mainland. And how long would it take for lemurs to lose interfertility with mainland relatives? Not just a generation or two.

We've already proven that rafting from Africa to Madagascar is not at all the same as rafting from South America to the Caribbean.

I never said they'd lose interfertility with the mainland species in a generation or two. According to your arguments on genetic diversity it would take at least hundreds of rafting events within a generation or two for the founding population to not become inbred and thus die out.

~Thylo
 
Nope: my point is that when conditions for rafting are optimal (weather and climate, vegetation, fauna, rivers), it isn't a matter of singular rafts. In some parts of the world, such as Amazonia and the northeast South American coast, the rafts are actually commonplace. In others they aren't formed at all, and don't play any part in zoogeography. Remember that for every successful rafting, many failed either before or upon landing, so multiple rafts were being washed downriver to sea.

I hope that clears it up, what I am trying to say. The very fact there were numerous coloniations of Madagascar by rafting, demonstrates a time when rafts were washed out frequently. That primates were part of the immigrant fauna, surely demonstrates a time when the mainland was more forested and riverine. Whereas the low chance of carnivores rafting, inferred from the global pattern of distribution, suggests things were once particularly optimal for them. Though the native rodents are not murines, they are at least murids, and might have dispersed under suboptimal (ie. late) conditions, as the murines did elsewhere.
 
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From where I'm sitting, this is how this conversation has gone and will continue to go:

a) you making wild claims while refusing to provide any evidence for your thinking
b) you calling out others for posting information without providing evidence
c) you ignoring the fact that even your own sources seem to indicate you're wrong
d) you selectively responding to whichever posts or sections of posts you think you can refute while ignoring all the rest
e) you continuously making new arguments that contradict your older arguments then pretending you never made the original arguments

Seems everyone else has abandoned this briefly amusing conversation so I will now do so as well.

~Thylo
 
Yea go back to saving muh wildlife, w the magic power of yr zoo tickets. :p As I saw it, this thread started with a defence of last ditch attempts at saving dead clades walking. Most recently the vaquita, now action is too long overdue to make a difference. Just the other day, people posted threads about how declines in a few British and East Asian birds have been largely ignored by zoos, although conservation zoos were surely able to take pre-emptive action in advance. They didn't though did they?
 
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Yea go back to saving muh wildlife. :p As I saw it, this thread started with a defence of last ditch attempts at saving dead clades walking. Most recently the vaquita, now action is too long overdue to make a difference. Just the other day, people posted threads about how declines in a few British and East Asian birds have been largely ignored by zoos, although conservation zoos were surely able to take pre-emptive action in advance. They didn't though did they?

Why do you think zoo's don't take action for native birds? Besides the education part (which I deem highly important), several zoos are working with European turtle doves. Walsrode has projects to save the golden plover and ferruginous duck in Germany, and don't get me started on the WWT in the UK. Several zoos have been involved in research for bird conservation (like Burgers' and their bewick's swans) or enhance the local avifauna in the zoo itself, like storks in Rheine and swifts and kingfishers in Nordhorn.

This is why I say I'm against zoo conservation, its not the principle, in fact ppl should do more for things like frogs and passerines.

But as you are against zoo conservation, I guess you don't approve the actions I described above?
 
Not against the principle of zoo conservation, but the practice which is misguided. You will notice out of all collections involved in conservation work by captive breeding, very few are involved in the cases you cited, and its particularly specialist collections such as WWT & Walsrode.
 
Platypus are difficult in captivity, while short-Beaked echidnas are relatively easy (they do still require specalised care, but a lot less so than the platypus).
 
Not against the principle of zoo conservation, but the practice which is misguided. You will notice out of all collections involved in conservation work by captive breeding, very few are involved in the cases you cited, and its particularly specialist collections such as WWT & Walsrode.
Charming as Sealpup undoubtedly is, I think some of what she's doing here, is her having fun at someone else's expense. I wonder what she has personally done for conservation?
 
Charming as Sealpup undoubtedly is, I think some of what she's doing here, is her having fun at someone else's expense. I wonder what she has personally done for conservation?
Uppities deserve it, and the tone of zoo conservation became uppity. Yet entire clades or taxon groups are still neglected, and things are still left too little, too late, too often. Attitudes surrounding contemporary zoos are bogging them down, and a part of this is the rebranding of zoos as consevation or ecology centers instead of... just zoos. Its not that I oppose captive breeding, its done in a way too misdirected, and unfairly biased toward charismatic megafauna.
 
The "unfair bias" you speak of really is extremely logical though, if you think about it.

First of all, conservation of species isn't something people have to do, it's something individuals choose to do. However, conservation and research costs a lot of money, and money isn't an infinite resource, so to be able to spend a lot of money that goes towards conservation (a charity, if you will), one has to make a lot of money first. Zoos could go on about an obscure species of warbler and pour a lot of money into the saving of that species, but they have to have money in the first place... And people prefer seeing and paying for things they're familiar with (pandas, tigers, elephants...) over some obscure small species they've never heard of.

Another important factor is the fact that "keystone species" still exist; if an apex predator or large herbivore goes extinct, an entire ecosystem might potentially collapse. If a small migrating songbird were to go extinct, it likely has a much, much smaller influence on the rest of the environment. Therefore it is better for zoos to create back-up populations of some species instead of others.

Conservation of species is (sadly) something very economical, and so choices have to be made. In my opinion, it's better we save some species than none at all. It's not about 'neglect;' captive breeding programs are the exception rather than the rule.
(Though I'll be the first to support any breeding programme for a smaller, less well-known species!)
 
Following Vision's point, I like the WCS's method where they work to preserve ecosystems and specific habitats (and thus all of the species which live there) by making a specific species the public will latch onto to be the mascot of their efforts. Examples include tigers in Russia and gorillas in the Congo. Yes the advertise mainly the large popular megafauna, but they're really helping a lot of smaller species.

~Thylo
 
Uppities deserve it, and the tone of zoo conservation became uppity. Yet entire clades or taxon groups are still neglected, and things are still left too little, too late, too often. Attitudes surrounding contemporary zoos are bogging them down, and a part of this is the rebranding of zoos as consevation or ecology centers instead of... just zoos. Its not that I oppose captive breeding, its done in a way too misdirected, and unfairly biased toward charismatic megafauna.

I would strongly recommend you to try to meet some people in the zoo sector and get some insights in how zoos decide on what conservation processes to get involved in and how they do it. Unfortunately a lot what zoos do differs widely of what zoos communicate. You would be surprised with how many zoos are involved with some of the less high-profile species without communicating it as it is not sexy enough for the general public.
 
I would strongly recommend you to try to meet some people in the zoo sector and get some insights in how zoos decide on what conservation processes to get involved in and how they do it. Unfortunately a lot what zoos do differs widely of what zoos communicate. You would be surprised with how many zoos are involved with some of the less high-profile species without communicating it as it is not sexy enough for the general public.

A perfect example of this is Chester Zoo's work with European Sand Lizards. They captively breed and reintroduce to the wild one, if not two (or maybe they switched their work to a more endangered ssp?), subspecies of them.

~Thylo
 
A perfect example of this is Chester Zoo's work with European Sand Lizards. They captively breed and reintroduce to the wild one, if not two (or maybe they switched their work to a more endangered ssp?), subspecies of them.

And there are loads of other examples. Partula snail species don't get much publicity but have had massive zoological support, likewise many amphibian species have benefitted from such programmes too... But if the zoo wants to raise money by income then snails and frogs aren't going to draw in the crowds, therefore the cash won't flow down the chain to lesser known species.
 
And there are loads of other examples. Partula snail species don't get much publicity but have had massive zoological support, likewise many amphibian species have benefitted from such programmes too... But if the zoo wants to raise money by income then snails and frogs aren't going to draw in the crowds, therefore the cash won't flow down the chain to lesser known species.

Great example! I was referring to a zoo working with a native species specifically but yes you're 100% correct.

~Thylo
 
Thoughts about Sumatran rhino? Crippled since the early Holocene, much like the lingering mammoths and Irish elks of the mammoth steppe, or the North Pacific sea cow Hydromalis, harmed by climate changes before their final extinction during the Holocene. The same forces caused the earlier extinction of the woolly rhino, the Sumatran rhino's closest relative, with the chronology of skeletons showing evidence that a limited gene pool was increasing hereditary pathologies.

http://www.cell.com/current-biology/fulltext/S0960-9822(17)31466-5
DOI: 10.7717/peerj.3684

Other large bodied members of the same fauna (as the rhinos) are in decline. Now there are cultural or scientific reasons to save Sumatran rhinos, but I can't help but think this is primarily natural extinction at work, and saving attempts have (or will) fail. And what nature can do, must be happening all over the world by way of anthropogenic causes. Lions went extinct when their populations were isolated in areas the size of the Iberian peninsula during the Pleistocene: what is the prognosis for large predators today?

Surely genetic diversity matters in the case of the Sumatran (and woolly) rhinos.
 
I was referring to a zoo working with a native species specifically...

Ah, I didn't realise that we were talking about local species. In that case there are a fair few collections in the UK that have nature walks or encourage local wildlife to set up home in the zoo. Dudley, for example, has colonies of bats and also signage for said bats. Twycross, Paignton, Colchester and even urban London* all have areas of natural growth or nature walks.
And then there are Birdworld and Slimbridge which aren't trying to reintroduce small species; they've gone for bustards and cranes respectively! ;)


*I know we all hate the North Bank for its lack of animals but that isn't the point of this argument.
 
I have found my new role model

...

Richardson's approach was normal in the past, there is somewthng wrong with the over-caution, homogenisation and bureaucratic stagnation of supposed world class zoos today. In the UK this is called Jersey-ification, but people forget Durrell could not open Jersey Zoo today.

This is an interesting thread and raises a number of important issues, and discusses some species I have worked with. Before I comment I would like some clarification on what "Jersey-ification" means?
 
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This is an interesting thread and raises a number of important issues, and discusses some species I have worked with. Before I comment I would like some clarification on what "Jersey-ification" means?
Jersey-ification is the English term for all medium sized zoos converging upon the zoo the Durrells founded at Trinity, Jersey - a strong conservation focus, at least in presentation and especially in education departments, fewer large animals and fewer species (pre-Jerseyification collections, are decried as "postage stamp collections").

I don't find it fair upon Durrell or his zoo, which could not actually be founded today, thanks to what people call Jersey-ification. The process is however undeniable, as hit home when I finally went to Trinity... it felt like any mainland UK zoo. It didn't feel special and nor did the zoo seem to find itself special. (Highlights IMO were the Asian aviary and the wonderful reptile house.)
 
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