WildFact
›
Information Section
›
Terrestrial Wild Animals
›
Wild Cats
›
Tiger
White, Black & Golden Tigers
White, Black & Golden Tigers
|
White, Black & Golden Tigers
|
Indian Miniature Painting from Mughal Period on old handmade paper with natural colours depicting wild 'White Tiger'.
 *This image is copyright of its original author Source: https://m.alibaba.com/guide/shop/splendi...53312.html 
I think white tigers are formed due to non expression of orange colour genes. The genes for pigmentation must had been stressed to express or due to higher hunting success rates in their previous generations there must have been no need for camaflogue genes or orange colour genes and hence pale or white colour or colourless tiger is formed. This is just an opinion.
(03-16-2019, 12:09 PM)parvez Wrote: I think white tigers are formed due to non expression of orange colour genes. The genes for pigmentation must had been stressed to express or due to higher hunting success rates in their previous generations there must have been no need for camaflogue genes or orange colour genes and hence pale or white colour or colourless tiger is formed. This is just an opinion. Maybe. Like melanism in tigers is basically their black stripes on steroid... Our "black tigers" are actually pseudo-melanistic.
@Rishi what do you mean by that? Were u sarcastic?
Even black tigers must have had low hunting success rates in previous generations . Hence develop more black colour to hunt effectively during the night times. Golden tabby's must be for hunting effectively during day time. (03-16-2019, 01:03 PM)parvez Wrote: Even black tigers must have had low hunting success rates in previous generations . Hence develop more black colour to hunt effectively during the night times. Golden tabby's must be for hunting effectively during day time. That's not really how evolution works friend. You don't get what you need, rather if you are lucky enough to get what you need then you live long enough to pass it on... or else  Siberian tigers never had a white coat in the wild, although that'd be very successful in their habitat. But the mutation just didn't happen in them.  *This image is copyright of its original author Usually this kind of mutations take place because of error while copying the genes, in this case, too thick & numerous stripes. Or too faded stripes for golden tigers. The following part is my own speculation. The recent population crash of tigers during the '80-'90s may have something to do with it. Let me explain why i think so. Keep in mind these are all recessive genes & even if the genetic change happens in an individual it won't show. Yes, the first tiger to get the white coat's gene may not have been white itself. Only when two specimens, both carrying the gene mate will their cubs be black or white or golden. Because the gene was out there, this trait of pseudo-melanistic fur occasionally surfaced in Simlipal from time to time, while golden or white tigers hadn't been seen in the wild for past hundred years (1915-Mohan) until both were found in recent years. Then came the 2 decades of insurgency when tiger numbers were brought down drastically due to poaching. Some of the survivors clearly carried the recessive genes & then their numbers quickly increased back due to ramped up conservation measures. But now more tigers have those genes because the source population was small, meaning more of the animals are carriers ...like almost all tigers of Ranthambore have Machhli's blood. If she was melanistic, most tiger-cubs being born at Ranth today would be black. Because Simlipal was hit so bad (fell from almost 100 to a dozen) black tigers are so common there now, more than 10. But there's only 1 golden tiger & 2 white tigers, as numbers in Kazi or Nilgiri didn't crash that hard. Otherwise just like in black leopards, as long as normal tigers-leopards are equally successful in hunts & passing their genes, the traits due to recessive genes will be seen rarely. Black tigers may have some advantage while hunting in darkness, but other tigers aren't dying of starvation or their cubs aren't reaching adulthood at a lower rate. Even if some difference exist, it's not much & can be negated by a little hunting/mothering skill.
@Rishi well, Siberians live in different habitats. The main subspecies of tiger panthera Tigris Tigris lives in india under conditions that are strangely tough. Hence development of genes takes place among tigers only in tough conditions of certain places in the world. The rest of the world follows. Everything gets sucked in in some places. So, living here is completely different than rest of the world. The fruits of tough living surfaces and distributes to all the organisms of the same species in the world. Even here some traits are not distributed because they are typical to certain geographical locations. In case of tigers that location is india. Gravitational waves are the answer. Living in the wild in some places is tough every moment for new comers here. Even indigenous organisms face tough situations. Doing every work is tougher here. So, the normal mode of pigmentation development too feels to be tough here. Adaptations i dare to say that must be almost continuous across generations are must here. So, everything must be tactful and every organism here is taught the harsh way and pushed to be the best, learning every tactic for survival in best way. The rest of world follows. So, development of pigmentation too is a work that is tough under extremely stressful conditions where as for other subspecies it is the basic phenomenon but not here.
Even i said that the evolution of higher hunting success rates to white tiger is lower probability of my answer and this occurs through some generations not a few. The higher possibility is stress for pigmentation that is a basic thing. 
@Rishi completely correct. Very very good.
 These coat variants are random error or variants or genetic mutants formed in nature continuously during sexual reproduction and recombinations and it is natural to happen and should happen. In which only very very small percentage are naturally selected individuals which show favorable adaptations to the changing conditions will survive and pass on their traits to progeny and the rest of the individuals of species will die due to circumstances or environmental conditions (Bottle neck and founder's effect too play roles). So that over time, the population of that species gradually filters out necessary characters morphological and physiologically through natural selection process resulting in subspecies further to entire species, genera and so on which inter breed only themselves. That's how Evolution works like a continuous flow or process. And these mutant tigers are formed due to inbreeding in our current Indian reserves in which these mutant genes are being carried as recessive genes. They become expressive due to inbreeding. Nothing more, these are just freaks that won't last "long" in survival unless environment changes favoring to their morphology. Man filtered these from wild and selectively breeding them in captivity for various purposes of his own. These golden, white, psuedo melanistic blah blah tigers should go extinction by stopping breeding them in captivity or breeding them with dominant variants over time to eliminate those recessive genes. In case of wild, it is high time to take measures against this inbreeding effect in ranth, gir, similipal etc.., whatever to stop this high abnormality rates and risk of wiping out as whole due to any type of catastrophe by either building corridors naturally or human intervened relocation. In Tiger canyons too white tiger specimens are sterilized to make them stop breeding as they don't have conservation importance.
After Nandankanan zoo in Odisha (where wild black tigers are found), the 2nd litter of black tigers in captivity were born in Andhra's (no wild black tigers recorded) Arignar Anna zoo this January & went on display last week.
A female white tigress Namrutha sired with a male tiger Nagula, who has the white gene, litter turned out to be two black cubs along with a white. I've been trying to find whether they were sourced from Odisha or their tigers had melanistic genes ancestrally present in them too.  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author
(Were these posted before?) http://feline-world.e-monsite.com/pages/...lipal.html
The first reports of black tigers, date from 1975 and 1976. A black specimen was shot down. A black tiger skin confiscated in 1992, of unknown origin, probably comes from the Similipal area, and another seized in the area in 1997.  *This image is copyright of its original author The most famous case dates from 1993. Confronted by a young tigress who was threatening him, in a village near Similipal, a young man shot her. It turned out that this tigress was black. She was examined, photographed and filmed. Her widened stripes, which even met on her belly, made her darker than ordinary tigers. The skin has been preserved.  *This image is copyright of its original author Painting by ???  *This image is copyright of its original author Some Black&White Photos, source unknown.
This video has an interesting footage and an old Indian painting of a white tiger:
Also, back in 2017, a white tiger was spotted at Nilgiris Biosphere Reserve, South India: https://www.thehindu.com/news/national/t...217223.ece *This image is copyright of its original author
The photographers point of view in capturing pale tiger,
https://www.team-bhp.com/forum/travelogu...serve.html Quote:There is no reason why a melanistic leopard couldn't survive in Africa but it hasn't been seen there in recent times and it seems mostly only seen in kabini, not throughout other Indian reserves.@Pckts Actually, there is a very common misconception amongst people about melanistic leopards of India. According to camera traps laid in Nilgiri Biosphere reserve and other places in Karnataka, Tamil Nadu and Kerala, more than 10% of all camera trapped leopards were melanistic. https://blog.nationalgeographic.org/2014/07/16/legendary-black-leopards-appear-on-camera-traps/ There was also a pseudo melanistic leopard camera trapped from Kerala which looked like a King cheetah in it’s markings. I am guessing the evergreen nature of the Western Ghats makes it conducive for them to thrive. And, you are right about Kabini. I have seen 3 melanistic leopards myself in Nagarhole (also the place where I saw my first tiger so is a special place in my life). (07-24-2019, 05:04 PM)Ashutosh Wrote:Quote:There is no reason why a melanistic leopard couldn't survive in Africa but it hasn't been seen there in recent times and it seems mostly only seen in kabini, not throughout other Indian reserves.@Pckts That reminds me of the issue of the 'Pogeyan', which was mentioned by the photographer Sandesh Kadur, and is known to locals in the area of Anamudi, the highest point of the Western Ghats, in the Indian state of Kerala. Its name means "The cat that comes and goes like the mist." During broad daylight, Kadur reportedly saw the felid in the high-altitude grasslands around Anamudi. He described it as being big, with a long tail and rounded ears. Its uniform colour was darkish grey. Of the known cats, the Pogeyan is most likely to be an Indian leopard, because it was described as being similar to the leopard in size and shape, the leopard is known to exist in the Western Ghats, and the furs of some leopards may differ from their main appearance of being yellow with rosettes, such as by being melanistic. https://scienceblogs.com/tetrapodzoology...n-the-ghat, https://books.google.com/books?id=GJhFAQ...YQ6AEINjAC, |
| Users browsing this thread: |
| 1 Guest(s) |