Leucism (Leukism)
Leucism is a genetic condition similar to albinism, but white tigers are not albino. Albinism is a deformity in an animal's ability to produce pigment, particularly melanin. Albinism affects the pigment in all of an animal's body including the eyes and other internal tissues. Leucistic animals have some pigmented areas because leucism is a deformity of the skin cells, particularly in their ability to support pigment. White tigers have pigmented eyes and stripes. Leucism caused the pigment in their skin to be diluted, giving them a white coat. Their stripes are pale in comparison with orange tigers, sometimes more brown than black. All white tigers have this genetic condition.
Rare White Tiger Myth
Now that we know why white tigers are white, it's easier to recognize that they are not a species or sub-species of tiger. The rare, or royal white tiger species is a myth. It is actually one of the most wide-spread and popularly believed frauds in existence. The reason this rumor was so widespread was in order for white tiger breeders to gain support from the public.
There are several sub-species of tiger, but leucism is only known to effect the bengal tiger. However, bengal tigers are not the largest tigers, siberian tigers are. For this reason, white tigers are typically a cross-bred hybrid of bengal and siberian tiger. This is why they are slightly bigger than bengals, and slightly smaller than siberians.
Leucism is a genetic condition similar to albinism, but white tigers are not albino. Albinism is a deformity in an animal's ability to produce pigment, particularly melanin. Albinism affects the pigment in all of an animal's body including the eyes and other internal tissues. Leucistic animals have some pigmented areas because leucism is a deformity of the skin cells, particularly in their ability to support pigment. White tigers have pigmented eyes and stripes. Leucism caused the pigment in their skin to be diluted, giving them a white coat. Their stripes are pale in comparison with orange tigers, sometimes more brown than black. All white tigers have this genetic condition.
Rare White Tiger Myth
Now that we know why white tigers are white, it's easier to recognize that they are not a species or sub-species of tiger. The rare, or royal white tiger species is a myth. It is actually one of the most wide-spread and popularly believed frauds in existence. The reason this rumor was so widespread was in order for white tiger breeders to gain support from the public.
There are several sub-species of tiger, but leucism is only known to effect the bengal tiger. However, bengal tigers are not the largest tigers, siberian tigers are. For this reason, white tigers are typically a cross-bred hybrid of bengal and siberian tiger. This is why they are slightly bigger than bengals, and slightly smaller than siberians.
In the Wild
Only 1 in every 10,000 wild tigers is white. Tigers have been on the endangered species list since 2010, and their current numbers in the wild are estimated to be from 2,500-3,200 and decreasing. About 1,850 of those are bengal tigers, so it's safe to say that there are no white tigers existing in the wild. The idea that white tigers live in snowy areas where a white coat could serve as camouflage is part of the myth explained above. Bengal tigers live in mangrove forest, dense forest and swampland habitats. As with albinism, leucism handicaps an animal's ability to camouflage itself from predators or prey.
History
All white tigers can have their ancestry traced to one cub named Mohan, who was captured in 1951. Mohan was bred to an orange female and produced three litters of orange cubs. Then he was bred with one of his orange daughters. This produced an all white litter consisting of one male and three females. One of these females (Mohan's daughter/granddaughter) was kept for breeding with Mohan for the rest of his days. One male and one female were transferred to New Delhi as a breeding pair. The last female was transported to Washington D.C. From then on, more white tigers from this family were bred with each other. Every white tiger in the world is a product of severe and consistent in-breeding.
Health Problems
The reason inbreeding causes problems in a population is that inbreeding prevents genetic diversity. Over time, traits may become homozygous (all the same) if no new individuals are introduced to the gene pool. This becomes serious when the traits are for genetic diseases. When homozygous parents are crossed, all of the offspring are guaranteed to share the same traits as their parents. Generation after generation, more recessive diseases start to show up in an inbred population, and when they do, they are there to stay. This decreases the fitness of the group, causing a sort of backwards evolution called inbreeding depression.
The following are genetic diseases that exist in the white tiger population:
Cleft Palates: A cleft is simply a gap, or opening, in this case in the roof of the mouth. It is caused by abnormal development during gestation. This deformity can be as severe as not having a palate at all (no separation between mouth and nose). The problem with tiger cubs with cleft palate is that it prevents them from nursing. The liquid could easily go up their nose and cause them to drown. Most animals born with cleft palates are humanely euthanized - it's unreasonable attempt to perform this type of surgery on an animal. Cleft palate may as well be a death sentence for a tiger cub.
Leucism: As discussed above, leucism is a deformity in the skin cells' ability to sustain pigment. This is a genetic condition like all the others, but this is the reason they are bred. Humans artificially select for this genetic condition, sometimes with an understanding of the implications and sometimes without. Leucism is genetically linked to vision problems, making it undesirable even in captivity.
There are many different ways for the vision to become impaired, including strabismus, photophobia, axial myopia [near-sightedness], congenital nystagmus [rapid involuntary movements of the eye], etc. These vision impairments make them more desirable for people who want to tame or train a tiger because they are slightly more dependent on the handler. These conditions are directly linked to the white gene, not inbreeding.
Strabismus (cross-eyed vision): The leucistic gene that causes tigers to be white also causes strabismus, or crossed eyes. This means that the optic nerve is wired to the wrong side of the brain. Even if the cat's eyes appear normal, their vision is always cross-eyed. They have problems with spacial orientation, and bump into things until they learn to cope with their poor eyesight as they grow older.
Photophobia: This is not a "fear of photos." It's sensitivity to light, due directly to strabismus. Because the optic nerve is wired to the wrong side of the brain, white tigers may experience pain or discomfort when exposed to bright light. Ironic, considering they're bred for the media attention.
Reduced Fertility and Miscarriages: Some deformities take affect before the cub is even born. It can prevent them from developing correctly and the result is fewer surviving cubs. Some are stillborn and many others are born alive, but die very soon after. They are too weak to handle the outside world. The mortality rate in newborn white tiger cubs in captivity is 70-80%.
Tiger cubs that survive birth must also survive examination by their mother. Mother tigers in captivity have been known to intentionally kill their cubs if they notice any unacceptable deformities. This is a practical survival technique in the wild - save the food for the healthy babies. This is part of why the death rate is as high as it is.
Scoliosis of the Spine: Instead of being relatively strait, the way a backbone should be, scoliosis causes it to curve to the side. This can happen anywhere on the spine, including the neck, resulting in life long problems for the tigers affected. These tigers would not live very long however, because they would not be displayable and therefore would be disposed of if not rejected by their mother.
Immune Deficiency: Immunodeficiency is a condition in which the immune system is either compromised or completely absent. This is very important because it's the tiger's only defense system against diseases other than genetic conditions. It's not uncommon for a cub to get sick and die shortly after birth, whereas a healthy baby could have lived.
Club Foot: This is a deformity of the feet, where one or more are turned inwards or outwards. It would appear as though they were walking on the sides of their feet, or their ankles. Tigers with deformed feet are not suitable for viewing and may even be killed by their mother.
Mental Impairments: It shouldn't be surprising that the deformities expand to the mind as well as the body. The white tiger below was famously known as the mentally "retarded" tiger. It's important to trainers that their animal be capable of learning and obeying commands. Mentally handicapped tigers are definitely throw-away tigers.
Facial Deformities: Bulging or blatantly crossed eyes, bulldog-like faces that are scrunched in with widely set apart eyes and misshapen skulls - usually large and dome-shaped. Crooked teeth that stick out from severe underbites. All of these grotesque physical deformities make a tiger unacceptable for viewing by the public, and they are typically destroyed, if they survive. Even if the cub survives the deformities themselves, it's very likely their mother will reject them.
Kenny (below) is a white tiger whose parents were both white siblings. He has leucism, strabismus, photophobia, mental impairments and facial deformities.
Only 1 in every 10,000 wild tigers is white. Tigers have been on the endangered species list since 2010, and their current numbers in the wild are estimated to be from 2,500-3,200 and decreasing. About 1,850 of those are bengal tigers, so it's safe to say that there are no white tigers existing in the wild. The idea that white tigers live in snowy areas where a white coat could serve as camouflage is part of the myth explained above. Bengal tigers live in mangrove forest, dense forest and swampland habitats. As with albinism, leucism handicaps an animal's ability to camouflage itself from predators or prey.
History
All white tigers can have their ancestry traced to one cub named Mohan, who was captured in 1951. Mohan was bred to an orange female and produced three litters of orange cubs. Then he was bred with one of his orange daughters. This produced an all white litter consisting of one male and three females. One of these females (Mohan's daughter/granddaughter) was kept for breeding with Mohan for the rest of his days. One male and one female were transferred to New Delhi as a breeding pair. The last female was transported to Washington D.C. From then on, more white tigers from this family were bred with each other. Every white tiger in the world is a product of severe and consistent in-breeding.
Health Problems
The reason inbreeding causes problems in a population is that inbreeding prevents genetic diversity. Over time, traits may become homozygous (all the same) if no new individuals are introduced to the gene pool. This becomes serious when the traits are for genetic diseases. When homozygous parents are crossed, all of the offspring are guaranteed to share the same traits as their parents. Generation after generation, more recessive diseases start to show up in an inbred population, and when they do, they are there to stay. This decreases the fitness of the group, causing a sort of backwards evolution called inbreeding depression.
The following are genetic diseases that exist in the white tiger population:
Cleft Palates: A cleft is simply a gap, or opening, in this case in the roof of the mouth. It is caused by abnormal development during gestation. This deformity can be as severe as not having a palate at all (no separation between mouth and nose). The problem with tiger cubs with cleft palate is that it prevents them from nursing. The liquid could easily go up their nose and cause them to drown. Most animals born with cleft palates are humanely euthanized - it's unreasonable attempt to perform this type of surgery on an animal. Cleft palate may as well be a death sentence for a tiger cub.
Leucism: As discussed above, leucism is a deformity in the skin cells' ability to sustain pigment. This is a genetic condition like all the others, but this is the reason they are bred. Humans artificially select for this genetic condition, sometimes with an understanding of the implications and sometimes without. Leucism is genetically linked to vision problems, making it undesirable even in captivity.
There are many different ways for the vision to become impaired, including strabismus, photophobia, axial myopia [near-sightedness], congenital nystagmus [rapid involuntary movements of the eye], etc. These vision impairments make them more desirable for people who want to tame or train a tiger because they are slightly more dependent on the handler. These conditions are directly linked to the white gene, not inbreeding.
Strabismus (cross-eyed vision): The leucistic gene that causes tigers to be white also causes strabismus, or crossed eyes. This means that the optic nerve is wired to the wrong side of the brain. Even if the cat's eyes appear normal, their vision is always cross-eyed. They have problems with spacial orientation, and bump into things until they learn to cope with their poor eyesight as they grow older.
Photophobia: This is not a "fear of photos." It's sensitivity to light, due directly to strabismus. Because the optic nerve is wired to the wrong side of the brain, white tigers may experience pain or discomfort when exposed to bright light. Ironic, considering they're bred for the media attention.
Reduced Fertility and Miscarriages: Some deformities take affect before the cub is even born. It can prevent them from developing correctly and the result is fewer surviving cubs. Some are stillborn and many others are born alive, but die very soon after. They are too weak to handle the outside world. The mortality rate in newborn white tiger cubs in captivity is 70-80%.
Tiger cubs that survive birth must also survive examination by their mother. Mother tigers in captivity have been known to intentionally kill their cubs if they notice any unacceptable deformities. This is a practical survival technique in the wild - save the food for the healthy babies. This is part of why the death rate is as high as it is.
Scoliosis of the Spine: Instead of being relatively strait, the way a backbone should be, scoliosis causes it to curve to the side. This can happen anywhere on the spine, including the neck, resulting in life long problems for the tigers affected. These tigers would not live very long however, because they would not be displayable and therefore would be disposed of if not rejected by their mother.
Immune Deficiency: Immunodeficiency is a condition in which the immune system is either compromised or completely absent. This is very important because it's the tiger's only defense system against diseases other than genetic conditions. It's not uncommon for a cub to get sick and die shortly after birth, whereas a healthy baby could have lived.
Club Foot: This is a deformity of the feet, where one or more are turned inwards or outwards. It would appear as though they were walking on the sides of their feet, or their ankles. Tigers with deformed feet are not suitable for viewing and may even be killed by their mother.
Mental Impairments: It shouldn't be surprising that the deformities expand to the mind as well as the body. The white tiger below was famously known as the mentally "retarded" tiger. It's important to trainers that their animal be capable of learning and obeying commands. Mentally handicapped tigers are definitely throw-away tigers.
Facial Deformities: Bulging or blatantly crossed eyes, bulldog-like faces that are scrunched in with widely set apart eyes and misshapen skulls - usually large and dome-shaped. Crooked teeth that stick out from severe underbites. All of these grotesque physical deformities make a tiger unacceptable for viewing by the public, and they are typically destroyed, if they survive. Even if the cub survives the deformities themselves, it's very likely their mother will reject them.
Kenny (below) is a white tiger whose parents were both white siblings. He has leucism, strabismus, photophobia, mental impairments and facial deformities.
Why not breed white tigers with orange tigers?
The white coat is coded for by a simple recessive gene. Orange tigers can be carriers for the white gene, but only if they have a white tiger somewhere in their ancestry. Orange tigers with white lineage are also bengal-siberian hybrids and will inherit the same genetic health problems. This means that they also cannot be released into the wild or part of conservation breeding programs and health problems may add to their struggles. But most importantly, breeding healthy orange tigers to these white ones will cause even their orange offspring to inherit diseases. The tiger population is endangered and declining. Their genetics are of invaluable importance to the survival of their species. However, cross-breeding is sometimes done in the hope that eventually this will not be the case. The vision impairments are genetically linked to the white gene. Those issues will never be bred out of the population, they're simultaneously bred into them along with the white coat.
Business
There are legal ways to purchase tigers (I strongly advise against this). A typical orange tiger will go for anything between $13,00 to $15,000. White tigers are much more valuable, worth anywhere from $50,000 to $150,000. There are different breeders who operate on different levels of legality, smuggling the animals from place to place as is done with many large exotic cats. A lot of paperwork is involved in order to be legal. White tigers are almost always bred with other white tigers simply because this combination would produce a 100% white litter which is efficient for a business. White tiger cubs that survive the mortality rate are then only allowed to live if they are acceptable for viewing. Orange cubs are eledgedly grouped with these unacceptable cubs called "throw-away" tigers (Kenny would have been a throw-away tiger had he not been rescued). These animals are bred for profit, entertainment, or publicity - but never conservation.
Legality
It is a state law, not a federal one, that determines whether or not you can own a big cat in the US. Private ownership of exotic big cats is legal in approximately 30 states. Some states, including Rhode Island, require a permit or a license, and some places are effected by local laws dictating how the cats must be purchased and cared for. There is no law stopping people from continually inbreeding white tigers.
Conservation Value
The purpose of conservation is to preserve species that occur naturally in the wild, to save them from extinction. White tigers are as artificial as anything else man-made. Therefore the term "conservation" does not even apply to them. All white tigers are destined for a life in captivity. Releasing them into the wild with their white coat to prevent them from hunting could be considered cruel. No conservation program currently has any plans to release white tigers into the wild. They will also not release hybrids as long as pure, healthy populations of each sub-species are present in their respective regions.
The white coat is coded for by a simple recessive gene. Orange tigers can be carriers for the white gene, but only if they have a white tiger somewhere in their ancestry. Orange tigers with white lineage are also bengal-siberian hybrids and will inherit the same genetic health problems. This means that they also cannot be released into the wild or part of conservation breeding programs and health problems may add to their struggles. But most importantly, breeding healthy orange tigers to these white ones will cause even their orange offspring to inherit diseases. The tiger population is endangered and declining. Their genetics are of invaluable importance to the survival of their species. However, cross-breeding is sometimes done in the hope that eventually this will not be the case. The vision impairments are genetically linked to the white gene. Those issues will never be bred out of the population, they're simultaneously bred into them along with the white coat.
Business
There are legal ways to purchase tigers (I strongly advise against this). A typical orange tiger will go for anything between $13,00 to $15,000. White tigers are much more valuable, worth anywhere from $50,000 to $150,000. There are different breeders who operate on different levels of legality, smuggling the animals from place to place as is done with many large exotic cats. A lot of paperwork is involved in order to be legal. White tigers are almost always bred with other white tigers simply because this combination would produce a 100% white litter which is efficient for a business. White tiger cubs that survive the mortality rate are then only allowed to live if they are acceptable for viewing. Orange cubs are eledgedly grouped with these unacceptable cubs called "throw-away" tigers (Kenny would have been a throw-away tiger had he not been rescued). These animals are bred for profit, entertainment, or publicity - but never conservation.
Legality
It is a state law, not a federal one, that determines whether or not you can own a big cat in the US. Private ownership of exotic big cats is legal in approximately 30 states. Some states, including Rhode Island, require a permit or a license, and some places are effected by local laws dictating how the cats must be purchased and cared for. There is no law stopping people from continually inbreeding white tigers.
Conservation Value
The purpose of conservation is to preserve species that occur naturally in the wild, to save them from extinction. White tigers are as artificial as anything else man-made. Therefore the term "conservation" does not even apply to them. All white tigers are destined for a life in captivity. Releasing them into the wild with their white coat to prevent them from hunting could be considered cruel. No conservation program currently has any plans to release white tigers into the wild. They will also not release hybrids as long as pure, healthy populations of each sub-species are present in their respective regions.
This map (above) shows the distribution of all six tiger subspecies. Bengal tigers are only found within the borders of India and Siberian tigers live in the isolated northern range of Russia and northeast China.
Novelty
There is only one other reason to continue breeding white tigers. People like them. There are considered one of the most beautiful creatures in the world almost universally, and the world would be very sad to see them go. Everyone wants to find a way to make it work, so that the white tigers could stay but also live healthier lives. So far though, we haven't. It may be a tough decision, but we need to ask ourselves - is this a good enough reason to breed sick animals?
Statistics
-Only 1 in 10,000 tigers in the wild would be leucistic.
-According to some tiger trainers, only about 1 in 30 white tigers will consistently perform for handlers.
-Only 1 in 4 cubs from the pairing of a white tiger to a heterozygous orange tiger (carrying the white gene) are born white.
-70% to 80% of white tiger cubs die at birth
-There are approximately 130 white tigers in captivity in the world, all with origins in India.
My Personal View
I am strongly OPPOSED to white tiger breeding, exhibition, and exploitation in any way. This means I don't think that anyone should ever intentionally bring more white tigers into the world or use them to make a profit. The only good reason to own a white tiger today, in my opinion, is for a non-profit organization to provide sanctuary or use a rescued ambassador to educate the public about their situation. It must be kept in mind, however, that rescuing an individual tiger from a breeding operation will save that one animal, but will support the business and enable the breeder to breed more tigers. For this reason, I agree with Big Cat Rescue's decision not to take in white tigers from anyone trying to find an easy place to get rid of them because it would not end the cycle for future cats. The only tigers that should be rescued are individuals from breeding facilities that have been shut down, or in any way that acquiring the tiger doesn't support any more tiger breeding business.
I would be a little disappointed if there were no more white tigers in the world, just like everybody else, but I would be happy for the tigers. It's their lives, they don't deserve to live or die like this for superficial reasons. The orange tigers are the truly beautiful ones, because they are healthy and able to live fulfilling lives of quality. They are the ones that can be saved and released into the wild, because they actually belong in the wild. The white tigers do not need to be saved from extinction, they need to be saved from existence.
If you consider this to be an issue, click below to see what you can do to help.
Novelty
There is only one other reason to continue breeding white tigers. People like them. There are considered one of the most beautiful creatures in the world almost universally, and the world would be very sad to see them go. Everyone wants to find a way to make it work, so that the white tigers could stay but also live healthier lives. So far though, we haven't. It may be a tough decision, but we need to ask ourselves - is this a good enough reason to breed sick animals?
Statistics
-Only 1 in 10,000 tigers in the wild would be leucistic.
-According to some tiger trainers, only about 1 in 30 white tigers will consistently perform for handlers.
-Only 1 in 4 cubs from the pairing of a white tiger to a heterozygous orange tiger (carrying the white gene) are born white.
-70% to 80% of white tiger cubs die at birth
-There are approximately 130 white tigers in captivity in the world, all with origins in India.
My Personal View
I am strongly OPPOSED to white tiger breeding, exhibition, and exploitation in any way. This means I don't think that anyone should ever intentionally bring more white tigers into the world or use them to make a profit. The only good reason to own a white tiger today, in my opinion, is for a non-profit organization to provide sanctuary or use a rescued ambassador to educate the public about their situation. It must be kept in mind, however, that rescuing an individual tiger from a breeding operation will save that one animal, but will support the business and enable the breeder to breed more tigers. For this reason, I agree with Big Cat Rescue's decision not to take in white tigers from anyone trying to find an easy place to get rid of them because it would not end the cycle for future cats. The only tigers that should be rescued are individuals from breeding facilities that have been shut down, or in any way that acquiring the tiger doesn't support any more tiger breeding business.
I would be a little disappointed if there were no more white tigers in the world, just like everybody else, but I would be happy for the tigers. It's their lives, they don't deserve to live or die like this for superficial reasons. The orange tigers are the truly beautiful ones, because they are healthy and able to live fulfilling lives of quality. They are the ones that can be saved and released into the wild, because they actually belong in the wild. The white tigers do not need to be saved from extinction, they need to be saved from existence.
If you consider this to be an issue, click below to see what you can do to help.
25th of July, 2013
Updated 14th of January, 2014
Updated 14th of January, 2014