MUTANT BIG CATS - RED, BROWN, STRIPELESS & DOUBLE-STRIPED TIGERS

Mutants are natural variations which occur due to spontaneous genetic changes or the expression of recessive (hidden) genes. Recessive genes show up when there is too much inbreeding. In the past, the obvious reaction to any unusual big cat was to shoot it for the trophy room. As a result, many interesting mutations may have been wiped out before the genes were passed on. Some colour mutations which would disadvantage a wild big cat are bred in captivity and are not viable in the wild. It is questionable whether these mutants should be perpetuated for the sake of curiosity or aesthetics alone.

Some of the information here may also be found in "Mystery Cats of the World" and assorted articles by Karl Shuker. I am grateful to Paul McCarthy and Mary Ann Howell for researching and providing extensive material, information and corrections on tiger mutations.

Brown and red tigers and other anomalies have also been reported. According to F G Alexander in Harmsworth Natural History (1910): Concerning the tiger’s coloration, my field of observation has been limited to Rajputana, Central India, and Bundelkhand, the jungles in which may be called " open jungles." The colour of all the tigers killed by myself and by brother sportsmen has, with two exceptions, been of a light red ochre. I once lured a cave tiger from its lair before sundown by tethering a bleating goat to a post in front, and within twenty yards of the underground cave. The incident occurred in the Asseerghur jungles. The colour of that beast was dark red ochre, far darker than that of any other tiger I ever killed.

I have seen Siberian and Chinese skins, and have killed tigers during the hot weather, monsoon, and cold weather; and as regards the length of their hair, I have found very little difference between a cold-weather tiger and a hot-weather tiger. There was, however, one exception. In Pertabgurgh territory - which is within twenty miles of Neeinuch - on one eventful Sunday I killed an adult male tiger. Judging by the teeth, he was very old. In length he was only 8 feet 1 inch, but his fur was quite an inch long all over the body; his colour was ruddy ochre, the ruff round the neck was particularly full, and his whole appearance led me to regard him as a dwarf-like specimen. If the skin had been exposed for sale in a furrier’s shop, it would have been accepted as a Chinese or Siberian specimen. This uncommon beast was killed in the autumn of 1888.

There is no doubt that in dark jungles, such as those of the Siwaliks or the Dun forests, animals’ skins assimilate themselves to the localities wherein the beasts live. That is Nature’s general rule, but in open jungles the pigment of the tiger’s skin is invariably light. The Beemashunkur, Canara, and Belgaum jungles contain darker-coloured specimens, and I have seen skins from them all which were, on the average, far ruddier than the thirty-one I have obtained and a dozen more which I have seen killed. Black-and-white tigers are but freaks of nature, and can no more be accounted for than can albino blackbuck or black panthers. In the markings of tigers and tigresses I have noted that the black markings on the body and belly are broader on the male, and that the double black band often surrounds an island of white or ochre, whereas in the tigresses such "surroundings" are by no means so common.

A stripeless tiger was reported in eastern India's Sunderbans and was supposedly a local strain of Bengal tiger; it was reported in 1936 by WH Carter writing to the Times of 16th October 1936 "I was much interested in Captain Guy Dollman's letter on black tigers in The Times of October 14th, having been resident in the neighbourhood mentioned by him for years. 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 and not black, but perhaps his cousin in the hinterland found black more suited to his background. The author of the Gazetteer in question is, I believe, dead." These stripeless brown tigers were further documented in the early 1970s. In domestic cats, there are genes which turn black into dark brown and strong sunlight can produce a similar effect (known as "rustiness" in domestic cats). K Ullas Karanth wrote in "The Way Of The Tiger" that there was a tiger with scanty stripes photographed at Nagarahole in 1993.

In 1929, Reginald Pocock documented a brown tiger whose stripes were only a little darker than its coat's background colour i.e. dark orange-brown markings on a normal orange base colour; others are brown with black stripes. In "Lions and Tigers and Mares, oh My!" (2004), Gay Louise Balliet wrote that Josip Marcan had been researching tiger colouration and colour genetics for around 20 years and was interested in the rarer colours. Marcan selectively breeds for the rarer colours. His tigers at the time included a golden tabby Bengal (Assam); a brown-striped beige (Jasmine); melanistic whites (chinchilla gene with black stripes) and grey-striped melanistic whites (chinchilla gene with dilution of black to grey). The brown-striped beige bred by Josip Marcan may be due to non-extension of the black gene i.e. red pigment (phaeomelanin) is produced instead of black (eumelanin).

There are several reports of brown Bengal tigers with no stripes. In 1989, the Indian Forester published a short article S A Sagar and L A K Singh of Orissa's Similipal Tiger Reserve. They noted four different sightings, all made by experienced trackers, of stripeless tigers in 1961, 1977, 1979 and 1988. Like recent black tiger sightings these are located in a single geographical area and probably indicate inbreeding which is allowing recessive or aberrant genes to show up and be perpetuated. Red tigers display chocolate markings on a rich red background, though the distinction between brown tigers and red tigers is one made by the observer.

There have been unconfirmed reports from the Sunderbans of Reverse Striped Tigers whose coats have an abnormally dark background colour patterned with orange stripes. This is the reverse of the normal black-on-orange colouration. During 1996, yellow-striped black tigers were reported near Baladaghar and between Patabil and Devasthali. This may have been the cause of a Spotted Tiger where orange spots were present on a black background. This would appear to be a tiger form of pseudo-melanism/abundism, a colour variation that has been recorded in leopards. Others have dismissed the spotted tiger as an optical illusion caused by dappled shadows on a normally striped Bengal tiger.

One of the most famous "double striped tigers" was "Jungla", exhibited at Belle Vue Zoo, Manchester, during the 1850s (illustrated) and pitted against tigers and buffalo in fights. Reverend JG Wood wrote a detailed description a few years later for his "Illustrated Natural History". Jungla was then about 5 years old. In his "Illustrated Natural History" (1853, 1874) the Rev JG Wood writes:

“Jungla” is one of the finest, if not the very finest Tiger that has ever set foot on English ground, and even when penned in the straight limits of a wooden cage that would not permit his noble head to be raised to its full height, and only gave room for a single short step backwards and forwards, his grand proportions were most striking. His present age is about five years. In height he is about four feet, and the relative proportions can be judged from the illustration. The total length of the animal is said, by his keeper, to he thirteen feet six inches and in girth he measures four feet eight inches. The principal peculiarity in the appearance of this animal is, that nearly all the stripes are double, including those which partially surround the tail. Sometimes these dark streaks are very long, and sometimes comparatively short and very wide, leaving a broad interval of the golden-yellow fur between the outer and inner stripes. Between many of these streaks are placed a number of spots similar to those which appear on the leopard’s skin, but the spots are small in size and not so distinctly outlined as the stripes. They are rather thickly scattered by the shoulders and flanks, occasionally making their appearance on the sides. Over the eyes some black lines are drawn, which closely resemble a stag’s horn, and on the forehead runs a series of equally dark stripe. which remind the spectator of the figure of a bat with outstretched wings. The ears are black, with a solitary white spot upon the back of each ear.

His light yellow eyes are constantly changing their tint, at one moment becoming green, and at another time assuming a deep neutral tint. As is the case with all felines. The pupil of the eye varies rapidly in size, the passing of a hand near the front of the cage sufficient to make them contract to half their previous diameter. He has been matched against many antagonists, and always came off victorious in the fight, whether his opponent were a strong-horned and hard-headed buffalo, or a Tiger like himself. The last Tiger to which he was opposed was killed in fifteen minutes.

In November 1869, Mander's Menagerie, a large travelling exhibition in Britain, included in its stocklist "double striped royal Bengal tigers". Modern experts have suggested that the tiger was actually a Javan tiger (now extinct) as this had complex striping on its upper hind legs. Since then, a number of double striped Bengal tigers have been reported. A tiger's striping is variable ranging from fine double stripes like a mackerel tabby cat, through the normal pattern to heavy, broad stripes which partially obscure the background colour. The pattern depends on the sub-species to which the tiger belongs - some sub-species have minimal striping on the forequarters. In zoos, little regard was given as to which sub-species the tigers were when they were bred together and their descendants have intermediate patterns.

As well as unusual colours and patterns in tigers; tail-less tigers, intersexual tigers and tigers with unusually short tails have been reported. A short or absent tail could be due to either an accident, birth defect or gene mutation.

 

RED TIGERS

There are records of stripeless golden Bengal tigers in India dating back to the early 1900s. In 1929, Pocock described a brown tiger with stripes only a little darker than the coat's background colour (probably a golden tiger). No specimens were obtained and it may have been a single aberrant individual. Some Bengal tigers are very sparsely striped, with little striping on their bodies. A stripeless local strain of Bengal tiger; it was reported in 1936 by WH Carter writing to the Times of 16th October 1936 "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 and not black." These stripeless brown tigers were further documented in the early 1970s. In domestic cats, there are genes which turn black into dark brown and strong sunlight can produce a similar effect (known as "rustiness" in domestic cats). K Ullas Karanth wrote in "The Way Of The Tiger" that there was a tiger with scanty stripes photographed at Nagarahole in 1993.

Confusingly, white tigers may sometimes be known as "red tigers" due to the varying background colour (ranging from white to cream) and stripe colour (from dark grey to chocolate colour). The two "red tigers" shot on a tea estate at the southern boundary of Kaziranga, Assam (around 1928) and described by the taxidermist van Ingens where actually white tigers, probably with brown stripes.

USEFUL GENETIC TERMS

INBREEDING DEPRESSION & OTHER GENETIC ANOMALIES IN TIGERS

COLOUR MORPHS & POSSIBLE GENE COMBINATIONS IN WHITE TIGERS

Textual content is licensed under the GFDL.

For more information on the genetics of colour and pattern:
Robinson's Genetics for Cat Breeders & Veterinarians 4th Ed (the current version)
Genetics for Cat Breeders, 3rd Ed by Roy Robinson (earlier version showing some of the historical misunderstandings)
Cat Genetics by A C Jude (1950s cat genetics text; demonstrates the early confusion that chinchilla was a form of albinism)

For more information on genetics, inheritance and gene pools see:
The Pros and Cons of Inbreeding
The Pros and Cons of Cloning

For more information on anomalous colour and pattern forms in big cats see
Karl Shuker's "Mystery Cats of the World" (Robert Hale: London, 1989 - some of the genetics content is outdated)

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