White Lions and Tigers - Yay or Nay

White Lions and Tigers - Yay or Nay
04-02-2008

hey jeremy,

the word melanistic only refers to dark coated animals. the stuff in our skin, human skin, that causes us to tan is called "melanin". the degree of melanin in your skin effects the colour of it.

as stated above melanistic jaguars and leopards, are a mutation that has, since it often offers no real disadvantage, become a hallmark of the species. it is naturally dispersed through teh populations of these animals and melanistic animals therfore need not be inbred. for that reason we should have zero issues with zoos displaying and mixing melanistic leopards and jaguars into the general zoo population. the important thing is that this mutation established itself naturally, long long ago. unlike white tigers and lions the melanistic trait does not need us and our intentional inbreeding to ensure its survival.

04-02-2008

Thanks for the info Patrick,

I agree, so is focusing on the 'white gene' in the Lions and Tigers recessive breeding..?

04-02-2008

if by that you mean is a recessive gene responsible for white tigers and lions the answer is yes, it is.

as is the case with melanistic leopards (though its apparently a dominant gene is responsible for black jaguars)

in any event its all mutation and trial by natural selection - the process that drives evolution. however, in the white tigers and lions, natural selection dictated it to be an unsuccessful mutation, whilst it endorsed melanism as something potential advantageous.

thus if we release white lions and tigers in the wild, we are polluting the wild population with genes proven by nature to be unsuccessful. with lion and tiger populations shrinking all over the world, why would we ever wish to put that added pressure on them?

not only are we poaching them, their prey and destroying their habitat, are we are now going to mess with their natural evolution as well? injecting unfavouring genes into their population?!!!

fortunately, despite all the talk, i'm yet to hear of any white cats released in the wild.

so thats why if you are at any zoo or individual that associates white lions/tigers with conservation is actually full of %@&* and feel free to tell them such.

05-02-2008

Interesting-the white males I saw so far were not really impressive in comparison to most of the "normal" lion males I saw so far. Did You make a photo of him by chance? EDIT: nevermind, just used google; he looks to be pretty long-legged, isn't he?
I have never heard that hypermelanistic (that term would actually be more appropriate) animals have a shorter life-span; what I heard, read about and even witnessed myself once is the accumulation of health issues in white tigers-kidney & neurological deficits, anaesthesia problems, reduced intelligence, face deformities ("bulldog" face)-most likely a result of inbreeding depression. I'm personally rather happy that these poor creatures have not become common in most European zoos-let's hope it stays this way.

05-02-2008

When at this park I remembered thinking he was very large...

He didn't move in the five minutes or so I observed him... He was sitting on his haunches with his front legs straight and on top of a log, so that could explain my impression...

I was referring black jaguars/leopards... I remember reading a few years ago that when they occur outside of the rainforest areas of their range that it has a negative effect on their lifespan...

05-02-2008

i don't imagine a black, heat absorbing coat is helpful in hot, dry savannah areas of the americas and africa. i have read the black individuals in savannah areas tend to be more nocturnal that usual as a method for counteracting such. nor would a black coat seem quite as camouflaged in a savannah as a yellow, brown and black spotted one. of course the situation may very well be reversed in the cooler, dark rainforest. certainly in parts of forested asia, black leopards dominate. apparently the same is true in parts of the jaguars range.

interestingly a pair of black jaguars can produce spotted offspring, whilst two black leopards will breed true to their coat colour (due to the gene responsible being dominant in jaguars and recessive in leopards). the interesting thing about this is, that it means whilst both species shared a relatively common ancestor, the black mutation has popped up independently and differently in each species, after they have split.

and yet the result is the same. for both cats, melanism, regardless of how its produced in the genes, has proven highly successful.

both leopards and jaguars are highly diversified cats. they inhabit (or once inhabited) a wide range of habitats from savannah to deserts and rainforest to temperate woodlands. few other big cats can adapt to such a wide range of habitats. could it have something to do with the fact that these animals carry this black gene diluted amongst the population and ready to pop up and prove itself whenever a favouring habitat arises?

05-02-2008

This has a special name: convergent evolution (check out the wiki page, quite interesting)...

That makes a lot of sense to me..!

White lions/tigers
05-02-2008

I have to disagree with portions of Patrick's recent post. There seems to be a confusion about breeding tigers or lions in captive situations as being a conservation effort. Captive tigers, for instance will never be returned to the wild in any meaningful way, just is not going to happen. Zoos have hidden under the cover of endangered species programs for far too long.

There are exceptions with certain species but big cats are not among them.

The value of captive tigers or lions is to raise awareness and funds for in-situ conservation. White tigers and lions are probably even better draws and as such better at raising funds and getting attention to issues.

05-02-2008

I did see a documentry where captive bred Siberian tigers were being released into the wild. The survival was poor, I think only 3 out of 25 survived long.

06-02-2008

@ptig: Even if the white colour morphs are more attractive, I see no good in keeping and especially breeding animals with obvious health problems. This applies for both zoo as well as for domestic animals.

And in reference to the dwindling numbers of wild big cats: who knows; maybe some day, the specimen in zoos will be the only ones left. A terrible vision in terms of possible re-introduction, but unfortunately possible.

@patrick: Your question about correspondence of widespread habitat/colour morphs: don't forget e.g. the Jaguarundi & cougar with their different morphs.
There is another animal interesting in this context: the Common European adder. Its black morph, also called "Hell snake" in German, seems to occur mainly in the more Northern, colder areas of Europe-most likely, the black colour might help the snake to gain more heat from the sun and thus be longer active than other morphs when the days become shorter.
Which makes me wonder: has anyone ever heard of a black specimen of the Amur or any other of the more Northern leopard subspecies?

white tigers
06-02-2008

@sun wukong- There are hundreds oif white tigers around the world. Certainly there are some with inbreeding issues. The vast majority are healthy animals that do represent an animal that existed in the wild for hundreds or thousands of years. They do have an important role in tiger conservation.

06-02-2008

No, ptig-there are not just "some" with inbreeding issues; the correlation between the accumulation of definite health problems and the white morph is obvious; the very same is true in several cases of white domestic breeds, f.e. Dalmatian, white Bullterrier or white cats. It's truly not a "vast" majority of healthy animals, but rather the opposite. White tigers, btw., did not exist for "hundreds or thousands of years" in the wild; there have been very few reports of examples of the white morph in the wild, which just underlines that this is an occasional variant that does not prevail due to being not an advantage in competition (keeping the recessive heredity in mind). The extremely narrow founding base of the white tiger morph found nowadays in human husbandry and its deliberate inbreeding and subspecific interbreeding disqualify these animals, together with the health handicap, from having an important role in serious tiger conservation. The deliberate deception of the public by unscrupulous advertisement that this morph is an endangered species or subspecies is just another bone of contention.
MUTANT BIG CATS

06-02-2008

Sun Wukong is correct, as there have been numerous incidents of white tigers being deformed or destroyed at birth due to a series of defects. Inbreeding has tarnished the lineage of several tiger families in captivity, and it is a genetic trait that is rarely apparent in wild cats. The fact that it would not at all be advantageous allows for the commonly held belief that such individuals would not last as long in the wild as their more "normal" counterparts. Any deception of the public in terms of "conservation" is nothing but snake-oil salesmanship.

06-02-2008

Sun Wukong ,just to l;et you know their is a female Black Amur Leopard at Thrigby Hall Wildlife Gardens in the U.K so they do occur.

06-02-2008

Melanism cannot be treated as an example of convergent evolution. It occurs in at least 18 species of cats, in some more commonly than others.