“Stripeless” or “ghost-striped” tigers, the Golden Tabby and Snow White: Their genetic cause, occurrence in the wild, and how they got into the American captive tiger population.
Both Snow White and Golden Tabby tigers occurred naturally in the wild – particularly in Assam, North East India, where the genetic variation for “ghost-striping” may still be extant. Bengal tigers from this area were imported into America during the 1950’s, which is a likely explanation for the occurrence of both types of variant in the captive American tiger population.
Golden Tabby and Snow White tigers both exhibit suppression of the black pigment on the stripes, creating an impression of “almost stripelessness” or “ghost-striping”. This is caused by the same gene variant for both.
In 2013 scientists determined the genetic basis for the white coat to be a variation in SLC45A2 p.A477V.
In 2017 they identified the cause of stripe colour suppression in Golden Tabby and Snow White tigers to be a variation in CORIN p.H587Y, a “wide-band” gene resulting in greatly diminished black pigment in the stripes.  Both variations are recessive, meaning that a tiger must have 2 copies of the variant (ie homozygous) in order to express the trait, while a tiger with only one copy (ie heterozygous) will be a carrier of the trait. 
- White tigers with black stripes must be homozygous for the SLC45A2 white variant, and may or may not carry the CORIN variant in a hidden form
- Golden Tabby tigers must be homozygous for the CORIN variant, and may or may not carry the SLC45A2 variant in a hidden form
- Snow White tigers must be homozygous for both the SCL45A2 and CORIN
- Orange-with-black-striped tigers can carry (ie be heterozygous for) either, or both, the SCL45A2 and CORIN variants
The authors of the study note that more work is needed to understand how the CORIN variant actually works and interacts with other coat pattern genes, and if it has any other effects.
2. Records of “Ghost-striped” Tigers in the Wild
Early records of wild Snow White tigers are detailed in Snow White Tigers of Assam and More Snow White Tigers… Briefly, the early 19th century records of wild white tigers were mainly “ghost-striped”, ie with stripes “only visible in certain lights”, and were mainly from the North East of India, ie Assam:
Wild Snow White Tigers 
1809 (before) India: portrait of a (dead) white tiger head (could be the 1804 tiger)
1809 India: white tiger, stripes barely visible, taken alive to England (probably the Exeter Exchange specimen)
1851 Dibrugarh: White tiger killed, “completely white”
1879 Jaintia Hills: 2 white tigers, “quite white, just showing stripes in the light”
1891 (before) Khasi Hills: white tiger “nearly white”
1899 Dibrugarh: White tiger shot, “stripes hard to see”
1900 Boga Bagh: 2 white tigers, faint lemon patch, otherwise “quite white, faint stripes”
Wild Golden Tabby Tigers
Golden Tabby tigers are more difficult to find in the historical records, but the records of Snow White tigers show that the gene for “ghost-striping” was once present in the NE India tiger population, so we would also expect to find Golden Tabby tigers there in history – and indeed they were. In fact Assam is the only area of India that I have found so far to have clear indications of Golden Tabby Bengal tigers living in the wild.
According to the Van Ingen brothers who provided the photograph: “The red tigress in the foreground was shot some years ago in Assam by the late Mr W G Forbes. The skin was white with the pale tan background and marked with fine stripes in a darker shade of tan. Curiously the three last stripes at the tip of the tail were black. The white tiger shown in comparison was pure white and marked with chocolate stripes. This tiger was shot by the Ruling Chief of Korea also some years ago.” (ie Koriya, the former princely state of Korea in India).  J.C.Daniel gives further information: The two light-coloured tigers shot by W.G. Forbes of Hathikuli Tea estate in 1929 were described at the time of curing by Messrs. Van Ingen as ‘red tigers’. 
Later writers place the area of Assam as the Southern border of Kaziranga, and some grouped these tigers with “white tigers”, but the Van Ingens’ letter and photo make it clear that they were Golden Tabby colouration.
2017 Assam, India – tiger photographed in Kaziranga
A photograph of a wild Bengal tiger in Kaziranga was recently posted online here:
I do not know if it has been authenticated, however, it does show a Golden Tabby tiger with pure Bengal characteristics, ie not likely to be one of the American-origin Bengal/Amur tigers. Given the history of “stripeless” tigers in the area in which it was photographed, it is plausibly authentic.
RI Pocock: “the red tiger, illustrated in our coloured plate….is a unique type with all the black pigment abstracted from the stripes, leaving them reddish-brown and only a little darker than the ground colour…The dressed skin of a tigress ticketed ‘Northern slopes of Mount Elburz’ and presented by Col. R.L. Kennion who told me it was presented to him by a native chief. This tiger, represented in the coloured plate, is of extreme interest. The ground colour and the pattern are as in the Afghan specimen; but there is not a trace of black on the skin, all the stripes being brown and indistinctly defined owing to their approximation to the general hue of the coat.” 
This could well be a Golden Tabby – but Pocock also notes that this may be one extreme end of the variation in stripe colour that occurred in the Caspian tiger (ie black to brown to paler brown).
3. Care Needed in Interpretation of Historical Records
Golden Tabby tigers are rather difficult to track down in the historical records. The terms “Golden Tabby”, “Strawberry” or “Golden” are of fairly recent origin and were not used to describe them in the past in India, so it becomes a matter of understanding the different terminologies used. The following cautions apply:
Two different types of “stripeless”
There are 2 different reasons a tiger might be described as “stripeless” or “nearly stripeless”, either:
- The stripes are there, but so faint that they are hard to see because of the colour reduction – the Golden Tabby and Snow White with the CORIN variation are in this category. 
- The stripes are greatly diminished in number but those remaining are of normal dark colour – there is no pale remnant of the missing stripes to be seen. There have been several tigers recorded with a noticeable reduction of stripes, and an extreme case might be described as “nearly stripeless”. These are probably not Golden Tabby tigers. 
Variations in Colour and Terminology
Tigers come in a variety of colours, even the common orange-with-black-stripes type can vary from a pale/tawny/bright-orange/rufous/deep-brown background with black/reddish-black/brown stripes. Different authors have used different terms to describe colours in tigers. Van Ingen used the term “red tiger” to describe the Golden Tabby, yet “red” was also used to describe dark rufous coloured tigers. “Pallid” could mean white, or it could mean pale gold, or pale-striped. “Brown” was used to describe a rare chocolate-brown-with-black-stripes – but “brown” is also commonly used, even today, to describe the common orange-with-black-stripes variety. (eg the cubs of a white tigress who was outcrossed to an orange tiger are often described as “brown” meaning “not white”.) 
To add to the confusion an author will sometimes quote a previous author in an abbreviated form, and later readers may misinterpret this abbreviated quote. Eg Was that “pale” tiger white ? Were those “nearly stripeless” tigers lacking stripes, or with colour-reduced stripes ?
Thus it is very important to trace back as far as possible to the original source of the information to find out exactly how a tiger was described by the actual observer.
4. Some Possible Records of Golden Tabby Tigers in the Wild
In the records listed previously, the original sources were explicit in their descriptions and/or provided illustrations. However the following records of possible Golden Tabby tigers are not conclusive, given the cautions outlined above.
1932 Mysore Pradesh, South India ?
“The last recorded wild golden specimens were a pair shot in 1932 at Mysore Padesh.” [sic] 
This statement is repeated in many articles, but with no reference given. It is possibly a misinterpretation of the Assam pair described above. The Van Ingens’ photograph of the skins was published and signed Mysore 1941, but the location of shooting of the tigers – Assam – was given on a previous page of the book.
1961-88 Similipal, Orissa, India – “tigers without stripes”
In a letter to “The Indian Forester” in 1989 AR Sagar (Field Director) and IAK Singh (Research Officer) of the Similipal Tiger Reserve in Orissa described 4 instances of “tigers without stripes” seen by – 
1988: a forest guard at N Similipal
1977: an experienced tracker in NW Similipal
1979: same tracker in NE Similipal
1961: Senior officer of the IPS cadre in Chitrakonda close to Orissa-Andhra Pradesh border
1917 Sunderbans, India – Tigers with only a few dark stripes
In the JBNHS, 1937, S H Prater of the Bombay Natural History Society wrote “Mr W H Carter (Times, 16 Oct 1936) writes ‘In one of the official district Gazetteers of Bengal (Khulna or Backerganj) there is mentioned a local variety of tiger which had lost its stripes as camouflage in the open sandy tracts of Sunderbans. The uniform colour scheme adopted was however, brown”. 
But the original report is a little different – in the Gazetteer, dated 1917: “…those frequenting the sand dunes along the sea face of the Sundarbans have almost lost their stripes in adaptation to their environment, so that their coats are of a tawny orange with only a few dark lines”. 
5. Source of the American Golden Tabby and Snow White Tigers
Tigers with “ghost-stripes” were first born in captivity in the American white tiger population. From 1979 to 1985 the prolific white tiger pair Bhim and Sumita at Cincinnati Zoo produced about 20 white cubs, a quarter of which were Snow White. Today they have many descendants internationally, including both Snow White and Golden Tabby tigers (via matings with orange tigers of the line).
Bhim and Sumita were descended from 4 founder tigers: 
- Mohan and Begum of the Rewa line of white tigers
- Susie, an orange-with-black-stripes “imported circus Bengal”
- Kubla, a pure-bred Amur tiger whose parents were wild-born
There have been no reported Golden Tabby or Snow White tigers in the studbook-registered Indian captive tiger population, so it is highly unlikely that the “ghost stripe” variation came from Mohan or Begum, leaving Bengal Susie and Amur Kubla as the only candidates.Susie – the Circus Bengal
Susie’s ancestry is not known for sure. She is reputed to have been born in 1959,  and as an adult was purchased from Sarasota, FL, in 1965 by the Great Plains Zoo in Sioux Falls, SD.  Her parents were likely wild-born imports. (see [future article] for more information about Susie)
When “Bengal” tigers were imported into America in those days, it was often not known exactly where they came from. However, there was one animal collector who made several unusual trips to Assam in the 1950s, to obtain Indian Rhino from Kaziranga, and elephants from the Garo Hills. This was Peter Ryhiner, and on his trips he also obtained other animals in the area – including tigers/cubs – to be sold in America. Most of these were sold to Animal Dealer Zeehandelaar (FL), who on-sold them to Circuses and Zoos. Kubla – the Amur Tiger
Kubla’s parents were registered wild-born Amur tigers bought in 1955 by the Como Park Zoo in Saint Paul, Minnesota. They were reputed to have been captured in Manchuria, Northern China.  There are old records of white tigers in China, rumours of them in Siberia, and an unconfirmed sighting of a white tiger in Manchuria in the 1930s. 
I have found no mention of “stripeless” tigers in those areas, either white or golden – some of the white skins in China were specifically described as being striped with black. However, the “red tiger” described by Pocock above was a Caspian tiger, a subspecies which has recently been found to be extremely closely related to the Amur , although the location of this “red tiger” was far from Manchuria.
So there is a slight possibility that the white gene came from Kubla, and an even slighter possibility that he carried the “ghost-striping” gene – but it seems far more likely that his Bengal mate Susie was the source of both.
6. Notes and References
 The Genetic Basis of White Tigers, by Xu X, et al Curr Biol 2013;23
 The genetics of tiger pelage color variations, by Xu X, et al. Cell Research 27, 954-957 (2017)
 For explanation of how a recessive trait is carried or expressed see White Tiger Genetics – The Basics
The CORIN variant is separate from the “white gene” but is inherited in the same way.
 For details and references of the snow white tigers see The Snow White Tigers of Assam and More Snow White Tigers….
 “Variation in Colour of Tigers and Panthers” by Van Ingen & Van Ingen, in JBNHS v.42:pt.3-4 (1942)
 Book: “The Tiger in India” by JC Daniel, 2001.
 “Tigers” by RI Pocock, in JBNHS v.33:pt.3-4 (1929)
 For an example of “a tigress from Nepal showing unusual reduction in the stripes” see Pocock 1929 , Plate D. This is a mild example but shows that the stripes are missing, not just light in colour.
 For examples of “brown” being used to describe orange tigers with black stripes see Nandankanan’s Ipsita gives birth by M Narasingh Rao, in Odisha Today 11 Nov 2009: “..one of the cubs is white in colour while three are brown“.
or White tigress to mate with brown tiger in Vandalur zoo by K Preveen Kumar, in The Times of India, Chennai. Oct 7 2010. “…zoo authorities are planning to shift…a white tigress to the enclosure of…a male brown tiger….hoping to get brown cubs. The two brown tigers we currently have at the zoo…” etc
 for example: Rare Tiger Cubs Call Polk County Home By Linda Florea, in Orlando Sentinal, Apr 13 2003.
 1989 “Tiger without stripes” by S.R. Sagar and I.A.K. Singh, in “The Indian Forester” April 1989
 Letter from S H Prater, Bombay Natural History Society, in JBNHS v39: 1937-8
 The Provincial Geography of India – Bengal, Bihar and Orissa, Sikkim. LSS O’Malley, 1917
 “White Tigers and Their Conservation” by AK Roychoudhury, in Tigers of the World, 1st Ed, 1987, Tilson & Seal Ed.
 http://messybeast.com/genetics/tigers-white-genealogies.htm See chart 3.
 Argus-Leader, Sioux Falls, SD, Wed, Feb 3 1965, p2. and Wed March 31, 1965, p7.
 “The Wildest game” by Peter Ryhiner and Daniel P Mannix, Cassel London, 1959. & May 11, 1954 The News Tribune from Fort Pierce, Florida · Page 7; & September 14, 1955 Argus-Leader from Sioux Falls, South Dakota · Page 12
 September 10, 1955, The Minneapolis Star from Minneapolis, Minnesota · Page 1
 See History of White Tigers in the Wild, & “The Tiger’s Claw: The exploits of George Yankovsky, East Asia’s mighty hunter” by Mary Linley Taylor. London, Burke, 1956.
 Driscoll CA, Yamaguchi N, Kahila Bar-Gal G, Roca AL, Luo S-J, MacDonald D, O’Brien SJ. 2009. Mitochondrial Phylogeography Illuminates the Origin of the Extinct Caspian Tiger and Its Relationship to the Amur Tiger. PLoS ONE 4(e4125):1-8.
 Photo credit: Snow-white tiger photo in diagram is from www.Amazing-world-in-free-stock-pictures-and-photos.com. Diagram is by whitetigertruths.