Is integrity in species and subspecies important for captive populations?

[tschandler71]

true but then again "wooded" doesn't have to mean forest either. Obviously Giraffe's and other large antelope that rely on size (as opposed to relying on speed or group numbers for defense) like Kudu do inhabit "bushveld". You don't see these animals in unbroken plain because it doesn't fit their evolutionary advantages. They inhabit niches that on other continents are filled by deer - browsers at the tree line.

I tend to meld in my mind any open african grassland between Sahel and Bush Veld as being similar when they are not.

A book on the evolution of the "savanna" exhibit and how it evolved would be interesting. What we often refer to Savanna can be as many as 9/10 different biomes then add in the fact you often see Reticulated Giraffe with Grant's Zebra (and with grant's gazelle) near Southern White Rhinos

I would love to see a specific zoo nerd in mind designed set of african exhibits which actually took the different biomes in a specific area (like east or southern africa) and did them without doing a single savanna exhibit. Folk would riot to hear about a new african exhibit that did - Wetlands, Mountains, Forest, High Veld, Bushveld, instead of your basic elephants rhinos hoofstock and sleeping lions set up.

 

[jbnbsn99]

I would love to see a specific zoo nerd in mind designed set of african exhibits which actually took the different biomes in a specific area (like east or southern africa) and did them without doing a single savanna exhibit. Folk would riot to hear about a new african exhibit that did - Wetlands, Mountains, Forest, High Veld, Bushveld, instead of your basic elephants rhinos hoofstock and sleeping lions set up.

That would be the Dallas Zoo.

 

[tschandler71]

Hence why Dallas is my number one of Zoo's I have been to.

Dallas - Jacksonville - Bronx (could be one but I went in 99 and don't remember most of it) St Louis - Nashville - Knoxville -Birmingham - Atlanta - Montgomery - Jackson are the ten (major) zoos I've been to ranked how I enjoyed them.

 

[ThylacineAlive]

Hence why Dallas is my number one of Zoo's I have been to.

Dallas - Jacksonville - Bronx (could be one but I went in 99 and don't remember most of it) St Louis - Nashville - Knoxville -Birmingham - Atlanta - Montgomery - Jackson are the ten (major) zoos I've been to ranked how I enjoyed them.

While Bronx probably would still rank in your Top 10 I think you'd like it much more in '99 than today just because of all the stuff that's closed down and left the collection since 2009.

~Thylo

 

[Jurek7]

Related is conservation of genetic diversity INSIDE existing species.

For example, recent report says that wild Bengal tigers lack most of the genetic diversity in 19. century tiger trophies. The subspecies (barely) survives, but most of its is lost.

Also, captive Golden Lion Marmosets were at one time more diverse than wild marmosets. Probably because founders came from extinct sub-populations.

It would be interesting if zoo curators look for founders coming from sub-populations which went extinct or endangered, and take special care to keep their genes. Slightly against the current practice that all animals in a species are genetically equal.

 

[ThylacineAlive]

Slightly against the current practice that all animals in a species are genetically equal.

I don't think that's true at all. I thought animals were paired together for mating based on how genetically diverse they are. All animals in captive populations aren't seen as genetically equal. For example, the Smithsonian National Zoo's male Transvaal Lion was (is still) held as the most genetically diverse Lion in North America and paired with his mate with that in mind.

~Thylo

 

[jbnbsn99]

I don't think that's true at all. I thought animals were paired together for mating based on how genetically diverse they are. All animals in captive populations aren't seen as genetically equal. For example, the Smithsonian National Zoo's male Transvaal Lion was (is still) held as the most genetically diverse Lion in North America and paired with his mate with that in mind.

~Thylo

One thing I've learned on this forum, never correct Jurek. He's always right.

 

[casarettoaleash]

I believe genetic integrity should be protected in both species and subspecies. But, inbreeding should be avoided. Only healthy, genetically sound, animals should be bred, too. When it comes to breeding, the most genetically diverse mate, within the subspecies, should be selected. Genetic diversity should be persevered within subspecies. Sadly, even wild Bengal Tigers have been polluted with Siberian Tiger blood. Decades ago a first generation cross between a Bengal and a Siberian Tiger was released into India. Approximately 1% of wild Bengal Tigers now contain Siberian Tiger blood.

 

[ThylacineAlive]

I believe genetic integrity should be protected in both species and subspecies. But, inbreeding should be avoided. Only healthy, genetically sound, animals should be bred, too. When it comes to breeding, the most genetically diverse mate, within the subspecies, should be selected. Genetic diversity should be persevered within subspecies. Sadly, even wild Bengal Tigers have been polluted with Siberian Tiger blood. Decades ago a first generation cross between a Bengal and a Siberian Tiger was released into India. Approximately 1% of wild Bengal Tigers now contain Siberian Tiger blood.

1% isn't bad at all. The majority of American Bison in the wild have cow blood in them! And about half the wild European Bison populations contain blood from two subspecies. And I've never heard of AmurXBengal crosses being released into the wild in India.

~Thylo

 

[Kifaru Bwana]

1% isn't bad at all. The majority of American Bison in the wild have cow blood in them! And about half the wild European Bison populations contain blood from two subspecies. And I've never heard of AmurXBengal crosses being released into the wild in India.

~Thylo

Arjan Singh.

 

[khakibob]

I'm always interested into why folks cross species, sub species, lines,etc, intentionally. Is it arrogance? Do some feel they can do a better job than nature, out in the back paddock & have it sustainable?

Yes, first crosses of most species can show some vigour in captivity but F2's, 3's & 4's are a mess & it takes lots of selection to have "your creation" breed true several generations later. Yes it can be done, but by very few breeders with OCD.

My experience with several species & their hybrids are that they lack "fitness" for their indigenous range. They lack the required anti preditor strategies of their parents & are quickly cleaned up in naturally occuring hybrid zones.

If zoo's are practicing "lifeboat conservation" then most hybrids have little conservation value unless they are the last chance for a species & to be used to breed back to origin. Very few understand this let alone have the resources. What's more important in these cases, temperament, or conformation? Who chooses the sire, the dam from many choices (& the competition within the boys), or the keeper with "his/her own" selection? There is sooo much more to think about, & it's my own view that after a few generations in a zoo even "pures" will have been culled for temperament (not intentionally, but PCM from flighty animals is a selection process) & lack the fitness required to evade predators without support if they are ever turned back out.

I'm a splitter in the worst way, but I'm also a realist.

Cheers Khakibob

 

[ThylacineAlive]

Arjan Singh.

Who's that?

@Khakibob- Many species/subspecies are crossed to get more impressive animals. Farmers mixed American Bison and Domestic Cattle together to get a more impressive and larger beef cattle. Zoos crossed white Bengal Tigers and Amur Tiger so that the white Bengals would be more impressive and larger.

~Thylo

 

[khakibob]

@Khakibob- Many species/subspecies are crossed to get more impressive animals. Farmers mixed American Bison and Domestic Cattle together to get a more impressive and larger beef cattle. Zoos crossed white Bengal Tigers and Amur Tiger so that the white Bengals would be more impressive and larger.

~Thylo

I'm well aware of these things & that they dont breed true after the first cross which may be "impressive" if some vigour is gained. However very carefull selection needs to be made for the next several generations from as large a selection a possible, if any improvements to the herd, mob, flock, etc can be guaranteed as heritable.

I have used some of these sub species recipies myself to produce "impressive" animals. The difference is I maintain pure parents & their lines to keep the heritability predictable in the offspring from the crosses & the offspring are not bred as they have no predictability in their heritability. In some species this means I maintain three seperate lines of pure sub species. I don't consider the offspring from these crosses better than their pure parents, although commercially they may be more impressive. I also don't kid myself that I have somehow cooked up a better animal than eon's of natural selection.

Cheers Khakibob

 

[ThylacineAlive]

What species do you cross-breed and why?

~Thylo

 

[khakibob]

What species do you cross-breed and why?

~Thylo

Several.
Didn't you answer this in your previous post? There is demand. I don't like producing crosses but some think they are more "impressive" than pures.

Cheers Khakibob

 

[ThylacineAlive]

Several.
Didn't you answer this in your previous post? There is demand. I don't like producing crosses but some think they are more "impressive" than pures.

Cheers Khakibob

Oh so you sell them, okay. Can you give me an example of what you breed? I wasn't aware that there were breeders around that specifically cross-bred subspecies for sale.

~Thylo

 

[khakibob]

Oh so you sell them, okay. Can you give me an example of what you breed? I wasn't aware that there were breeders around that specifically cross-bred subspecies for sale.

~Thylo

By request & only If I feel inclined too. There are lots of folks breeding crosses they just dont "specify" it.

Sale!! Making assumptions?

Cheers Khakibob

 

[nanoboy]

actually DavidBrown will tell you that they are separate species, and that is why they don't interbreed in the wild.

Yes, good point. We need the scientific community to get on board now.

 

[ostrich]

In my honest opinion, hybridization is just wrong. But, that is my personal opinion. That goes for species and subspecies alike. It’s a shame that some wild populations have been tainted. For example, Bengal Tigers like somebody mentioned. I don’t believe in crossing species. It pollutes the gene pool. However, on the other side of the argument, crossing species lines in very closely related species can produce hybrid vigor. I think this would only be beneficial in highly inbred populations. For example, some species of finches kept in captivity can produce hybrids and the offspring are often healthier. They aren’t worth much in the bird fancier world, though. But, since many finches are inbred to begin with, hybridizing species can be beneficial. I’m using Zebra and Society finches as my main example.