MUTANT LEOPARDS

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, either in isolated wild populations or in captive populations. Albinism (pure white), chinchilla (white with pale markings) and melanism (black) are the commonest mutations. Erythristic (red), leucistic (partial albinism/cream) and maltesing (blue) are also reported in big cats. Sometimes the markings are aberrant e.g. too sparse or too heavy (abundism), giving the appearance of a pale or dark individual. White, black, red, blue or cream mutations are similar to those found in domestic cats. Sometimes the pattern is different from normal. As well as anomalous colours, there are abnormally large or small individuals, longhaired individuals, short-tailed or even tail-less individuals. All of these occur in domestic cats so why are they less common in big cats? Wild cats displaying these traits may be less likely to survive to pass on the traits. In captivity, humans control which traits are bred, hence the multitude of domestic cat colours and types. In the wild, nature selects against any trait which does not enhance the animal's survival chances.

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.

I am grateful to Paul McCarthy for researching and providing extensive material on leopards.

 

LEOPARD MUTANTS

Leopards are generally buff/tawny with inky black spots arranged in rosettes. Melanistic leopards are relatively common and are bred in zoos and as exotic pets (black panthers). Black leopards are reported from moist densely-forested areas in south-western China, Burma, Assam and Nepal; from Travancore and other parts of southern India and are said to be common in Java and the southern part of the Malay peninsula where they may be more numerous than spotted leopards. They are less common in tropical Africa, but have been reported from Ethiopia (formerly Abyssinia), the forests of Mount Kenya and the Aberdares. One was recorded by Peter Turnbull-Kemp in the equatorial forest of Cameroon.

According to the “Illustrated Natural History” by the Rev JG Wood (1853, 1874): There are some [Indian] Leopards whose fur is so very dark as to earn for them the name of Black Leopard. This is probably only a variety, and not a distinct species. Although at first sight this Leopard appears to be almost uniformly black, yet on a closer inspection it is seen to be furnished with the usual pardine spots, which in certain lights are very evident. There have been often exhibited sundry Leopards of an exceedingly dark fur, and yet partaking largely of the distinct spottings of the ordinary Leopard. These were a mixed breed between the Black Leopard and the Leopard of Africa. The black variety of this animal is found in Java, and has by some authors been considered as a separate species under the title of “Felis (Leopardus) melas,” the latter word being a Greek term, signifying “black.”

The spotted pattern is still visible on black leopards, especially from certain angles where the effects is of printed silk. Black leopards are caused by a recessive gene and always breed true. It is sometimes erroneously suggested that black leopards are more fertile than the normal tawny form. According to Funk And Wagnalls' Wildlife Encyclopedia, black leopards are less fertile than normal leopards having average litters of 1.8, compared to 2.1. This may be due to their highly strung nature and finding captivity more stressful. They sometimes give the impression of being more fertile because they are selectively bred as exotic pets and because recessive genes breed true i.e. two black leopards will always produce black cubs. Captive black leopards may be more highly strung than spotted leopard; probably due to inbreeding. Because the animals are nocturnal hunters, melanism does not necessarily impede survival. Mounted specimens of black leopards are prone to fading, giving the impression of chocolate brown leopards and red leopards.

Most other colour morphs of leopards are known only from paintings or museum specimens. There have been very rare examples where the spots of a normal black leopard have coalesced to give a jet black leopard with no visible markings. Pseudo-melanism (abundism) occurs in leopards. The spots are more densely packed than normal and merge to largely obscure the background colour. They may form swirls and, in some places, solid black areas. Unlike a true black leopard the tawny background colour is visible in places. One pseudo-melanistic leopard had a tawny orange coat with coalescing rosettes and spots, but white belly with normal black spots (like a black-and-tan dog).

In Animal Life and the World of Nature (1902–1903), a pseudo-melanistic leopard with heavily speckled markings was described: “A very curious (and seemingly new) variety - if not sub-species of the leopard—is found in Northern Cape Colony and perhaps in Basutoland. It is of large size, but the rosettes have changed into innumerable tiny black spots thickly scattered over the rather umber-tinted fur of the upper parts. The bold black stripes of the throat and the black spots on the white belly are retained. In fact it is a parallel case to the Servaline Cat, which differs only from the common Serval by the substitution of many little spots on a dusky ground for the large clear black spotting on yellow. It would almost seem as though (but for the hindrance of man and his attempts at exterminating) a new species of leopard on rather leonine lines was being developed under our eyes in South Africa. With this exception the leopards of all Africa, and of India, Ceylon and Malaysia, are absolutely indistinguishable in appearance, size, and markings, though all these regions offer two distinct and similar types, according as the leopard in question inhabits the open or the forest country.”

In The Field No 2887, April 25th, 1908, Henry Scherren wrote "By the kindness of Dr P Chalmers Mitchell, Secretary of the Zoological Society, Mr Smith's drawing of a melanotic leopard obtained at Grahamstown is here reproduced. When Dr Gunther described that animal (Proceedings of the Zoological Society, 1883, p 243) the question of hybridity with a cheetah or a leopard for sire was discussed, but rejected in favour of the view that the animal was an instance of incipient melanism, the ground colour being tawny, with an orange gloss about the shoulders. With the permission of Dr Mitchell I shall shortly exhibit at a scientific meeting of the Zoological Society black leopard skins obtained in quite a different part of Africa" (While relatively common in India, black leopards are uncommon in Africa).

Pseudo-melanistic leopard, once posited as a leopard x cheetah hybrid (The Field, 1908)

In Harmsworth Natural History (1910), R Lydekker wrote: "In 1908, at one of the meetings of the Zoological Society of London, there were exhibited certain dark-coloured leopard-skins from Abyssinia, two of which were wholly black, while the others were what is called melanistic. These skins were made up into rugs, and it was also mentioned that other specimens of a similar character, reputed to come from Abyssinia, had been received on previous occasions in London, and treated in the same manner. The melanistic skins merely showed a deepening of the general colour, more especially on the two sides of the dorsal line; and an intensification of the same feature had evidently led to the production of complete melanism in the other two skins, both of which, when viewed in certain lights, revealed the existence of the normal black rosettes. in regard to general colouring these skins are, in fact, of the black Asiatic type. A similar skin has been obtained from Eastern Africa, hut in the rest of that continent black leopards seem to be unknown. There is, however, a peculiar dark phase in South Africa, a specimen of which was obtained in 1885 in hilly land covered with scrub-jungle, near Grahamstown. The ground-colour of this animal was a rich tawny, with an orange tinge; but the spots, instead of being of the usual rosette-like form, were nearly all small and solid, like those on the head of an ordinary leopard; while from the top of the head to near the root of the tail the spots became almost confluent, producing the appearance of a broad streak of black running down the back. A second skin had the black area embracing nearly the whole of the back and flanks, without showing any trace of the spots, while in those portions of the skin where the latter remained they were of the same form as in the first specimen. Two other specimens are known; the whole four having been obtained from the Albany district. These dark-coloured South African leopards differ from the black leopards of the northern and eastern parts of Africa and Asia in that while in the latter the rosette-like spots are always retained and clearly visible, in the former the rosettes are lost - as, indeed, is to a considerable extent often the case in ordinary African leopards - and all trace of spots disappears from the blacker portions of the skin. The idea has long been current that black leopards are much fiercer and more bad-tempered than those of the normal colouring.

The skin of a pseudo-melanistic leopard leopard was described in 1915 by Holdridge Ozro Collins who had purchased it in 1912: The wide black portion, which glistens like the sheen of silk velvet, extends from the top of the head to the extremity of the tail entirely free from any white or tawny hairs [...] In the tiger, the stripes are black, of a uniform character, upon a tawny background, and they run in parallel lines from the centre of the back to the belly. In this skin, the stripes are almost golden yellow, without the uniformity and parallelism of the tiger characteristics, and they extend along the sides in labyrinthine graceful curls and circles, several inches below the wide shimmering black continuous course of the back. The extreme edges around the legs and belly are white and spotted like the skin of a leopard [...] The skin is larger than that of a leopard but smaller than that of a full grown tiger." The cat had been killed in Malabar, India in 1912 and was later identified as a pseudo-melanistic leopard. Two pseudomelanistic leopards are shown below.

In May 1936, the Natural History Museum exhibited the mounted skin of an unusual Somali leopard. The pelt was richly decorated with an intricate pattern of swirling stripes, blotches, curls and fine-line traceries. This was very different to the pattern of spotted leopard, but rather similar to the pattern of the King Cheetah. Some modern cryptozoologists refer to the specimen as a King Leopard. Between 1885 and 1934, six specimens of pseudo-melanistic leopards were recorded from the Albany and Grahamstown districts of South, indicating that the gene mutation was present in the local leopard population. Others have been recorded from Malabar in southwestern India. The human penchant for shooting unusually patterned leopards appears to have wiped out individuals that carried the mutation.

A pseudo-melanistic leopard has a normal background colour, but its excessive markings have coalesced so that its back seems to be an unbroken expanse of black. In some specimens, the area of solid black extends down the flanks and limbs; only a few lateral streaks of golden-brown indicate the presence of normal background colour. Any spots on the flanks and limbs that have not merged into the mass of swirls and stripes are unusually small and discrete, rather than forming rosettes. The face and underparts are paler and dappled like those of ordinary spotted leopards

Pseudo-melanistic leopard or "king leopard" from Kerala, India

In 2012, a pseudo-melanistic leopard was reported in the Parambikulam forests in the Palakkad district of Kerala (in the Western Ghats), India. The black spots were closely packed to give it a designer coat. In the case of the deer, the white spots on its reddish fawn coat were overshadowed by the black pigmentation, giving the animal a blackish appearance. In this dense forest habitat, melanism and pseudo-melanism may be an advantage to the leopard.

Guggisberg noted that leopards can be extremely variable in their patterns. In a paper about panthers and ounces of Asia, Pocock used a photo of a leopard skin obtained from southern India; it had large black-rimmed blotches, each containing a number of dots and it resembled the pattern of a jaguar or clouded leopard. Another skin from southern India shown by Pocock had the normal rosettes broken up and fused and so much additional pigment that the animal looked like a black leopard streaked and speckled with yellow.

In the early 1980s, Glasgow Zoo, Scotland acquired a 10 year old black leopard from Dublin Zoo, Ireland. She was exhibited for several years before apparently being sold to Madrid Zoo. The leopard had a uniformly black coat profusely sprinkled with white hairs, giving a silver "glitter" effect. The visual effect (of being draped with spider webs) led to her being nicknamed the "Cobweb Panther". The condition is known as piebaldism and has been seen in domestic cats. I have seen no reports as to whether the Cobweb Panther was ever bred to try to reproduce this effect. The condition is most easily seen on black cats. White spots appear on the coat; these become more extensive with age until the cat has a white lace pattern on the black fur. Ultimately the cat may go completely white. "Leukoderma" (white skin) and "Leukotrichia" (white hairs) are generic terms for piebaldism; it is a progressive "aquired depigmentation" i.e. a loss of pigment which occurs during the cat's lifetime and may be triggered by illness or environmental factors. Vitiligo is one form of leukoderma.

During the 1960s, one of two cubs born to a pair of normal spotted leopards at Colorado's Cheyenne Mountain Zoological Park was pure white, but apparently turned black at the age of five months.

Other leopard mutants include red (erythristic) leopards with chocolate brown markings on a reddish background described as "rich mahogany". Buff leopards with orange rosettes have occurred; probably due to erythrism in a spotted leopard. A wild erythistic spotted leopard was reported in April 2012 in South Africa's Madikwe Game Reserve. The male leopard, dubbed a strawberry leopard had a golden background with red spots and had been spotted by a number of tourists in the game reserve. Erythrism occurs when normal black pigments are not produced and red pigment is produced instead. This is possibly the result of the non-extension gene which is believed to be responsible for red leopards (black leopards where red had replaced the black colouration) and which is also seen in domestic cats. The red spotted coat still provides some camouflage (especially at dusk or night-time) and the "strawberry leopard" appears to be healthy and successful, but there is a fear that he could stray from the Madikwe Reserve into neighbouring game farms where he could be targeted by trophy hunters seeking a novelty.

Red spotted leopard (Strawberry Leopard), South Africa

Assuming that not all red leopard specimens are due to discolouration of black leopard taxidermy specimen, how common is the mutation and what genes are involved? There seem to be fewer than 5 erythristic leopards reliably reported so it would either be a rare spontaneous mutation or a rare recessive gene. The most likely gene is the Extension gene which has been identified in domestic cats (it is also called "red factor", "black modifier" and "agouti modifier"). The dominant form of the gene allows normal expression of black pigment, but if a cat inherits 2 copies of the recessive form (non-extension) it produces red pigment instead of black. If a normal spotted leopard inherited 2 copies of the recessive non-extension form it would have reddish rosettes on a normal background colour. If a black leopard inherited 2 copies of the recessive non-extension form it would have deep reddish-brown spots on a reddish-brown background, exactly what is reported for "red leopards". Black leopards occur due to recessive genes for melanism and are not uncommon in the Indian subspecies, but rarely if ever occur in other leopard subspecies. Red leopards could only occur if a leopard inherited 2 recessive melanism genes plus 2 recessive non-extension genes.

Red leopard from collection of Mirko Wölfling (University of Würzburg). It is believed this specimen came from a zoo and the red colour is due to the recessive form of the extension gene, not to taxidermy fading.

Red leopard

Red leopard taxidermy on display at a hunting supplies store.

Red leopard or fading specimen? To the left is a melanistic leopard, to the right is a melanistic jaguar (face only). The black pigment tends to fade, giving an impression of reddish animals. The darker colour of the jaguar specimen may be due to the fact that jaguar melanism is a dominant mutation while leopard melanism is a recessive mutation. In other species, dominant black has been observed to fade less than recessive black. In an erythristic individual, the black pigment is turned to red, possibly due to the recessive form of the extension gene (red factor gene).

Melanism gene (recessive)

Extension gene (recessive)

Normal spotted (black on tawny)

0 or 1 copy

0 or 1 copy

Black leopard

2 copies

0 or 1 copy

Red spotted (red/orange on buff)

0 or 1 copy

2 copies

Red leopard

2 copies

2 copies

There are also pale cream leopards with pale markings and blue eyes (chinchilla mutants or dilute erythristics), striped leopards (possiblymis-identified as tiger/leopard hybrids), leopards with jaguar-like rosettes (darker central colour) and leopards without any distinct rosettes. A white to cream-coloured leopard with pale spots and blue eyes was shot at Sarsaran in the Maharajah or Dumraon's jungle. Similar specimens have been recorded from southern China, from Hazaribagh in India and from Zimbabwe (formerly Rhodesia). Pocock reported a purely white skin from East Africa; the spots were only visible in reflected light. Leopards with striped underparts have been noted. In Harmsworth Natural History (1910), R Lydekker wrote: The typical Indian leopard, as already mentioned, has the rosettes large and extending over most of the fore quarters. In the African leopard, on the other hand, the rosettes are everywhere smaller and more crowded, and on the shoulders and head break up into small solid spots. [...]. In ordinary leopards there are no black dots within the light area enclosed by the rosettes, but in some skins from Siam such dots are present, and thus serve to connect the leopard with the jaguar, in which they are normal.

Also in Harmsworth Natural History (1910), R Lydekker wrote: Far rarer than black leopards are white ones, of which but very few have been met with. On 6th may 1978, a pair of white leopard cubs were born to normal (spotted) leopards are Rome Zoo. Both had to be hand-reared. The male cub was whitish with light grey spots and died shortly afterwards. Post mortem showed internal abnormalities. The female survived and was snow white in colour. As she grew older, her coat turned pale grey and the spots became visible.

In "The Wildlife of India" by E.P. Gee wrote that in 1947, a letter in "The Statesman" of Calcutta asked "Who has ever seen a white leopard?" The question was answered a few years later in "The Field" describing a leopard skin obtained from a leopard shot in a princely state near Patna, Bihar: "The colouring was not due to albinism but lacked melanistic characteristics, there being no black markings, and the colour being of various shades of orange and cream resembling that of a really good tortoiseshell cat." Another very pale-coloured leopard was reported in "The Field" in 1953 regarding London Zoo's leopard from West Persia exhibited in 1910 or 1911: "indistinct, blackish spots in summer. When autumn came its now longer winter coat lost the spots and became so pale as to be difficult to see towards dusk." The latter suggests the chinchilla mutation where the pigment is only deposited towards the ends of the hair shaft; the longer the hair the paler the effect.

Mel and Fiona Sunquist wrote in "Wild Cats Of The World" "Albino leopards have been reported from India, China, Zimbabwe, and East Africa, but the instance of albinism appears to be rare. Pocock reports having seen only one true albino skin, which he believed came from Africa, but he also records a partially white skin in the British Museum in which the ground color was a cream and the markings tan.

A 1993 issue of the Journal of the Bombay Natural History Society contained an article listing 11 instances of albino, or partial-albino, leopards noted between 1905 and 1965. Most are from the Bihar and Madhya Pradesh areas of India. Unlike melanism, albinism would make a leopard more conspicuous and a less successful predator. Being both unusual and conspicuous, albino leopards would have fallen victim to big game hunters' guns. A wild-caught albino leopard called Jinx was apparently kept at the Central Park Zoo, USA between 1935-1960 and had originated from Mozambique; descriptions suggest a degree of ghost spotting. In "Management Of Wild Mammals In Captivity", the albino leopard at the Central Park Zoo was described as "An albinistic specimen of the tall East African race (Panthera pardus pardus) recently living in the Central Park Zoo, was a beautiful creature. Its ground color was pale buff, almost white, its spots were very light brown, and its eyes were pink. This animal, a male, was brought from Mombasa, with a normally colored male companion, as a 'leopard by lion hybrid.'" White leopards were apparently born at Los Angeles (USA) Wildlife Weighstation; these were leucistic i.e. white but with normal colour eyes. They developed spots as they grew older. A white, but apparently not albino, leopard cub born in Africa was sold to a zoo in Japan in the spring of 1999 and is called "Nana". Two leopard cubs were born at the Wildlife World Zoo in Arizona; one, named "Isis" was believed to be the only white leopard to be born in captivity. Several experts have confirmed that she has white skin, though she was described as having spots. Blood tests on Isis and her parents were planned if her skin remains white. Claws 'N' Paws Wild Animal Park, Pennsylvania also claims a white leopard.

COLOUR MORPHS OF LEOPARDS

Tawny (orange/normal)

Black (melanistic)

Albino (pink-eyed)

Black (pseudo-melanistic)

Red

Cobweb (captivity only)

Cream

Blue (maltese) (unconfirmed)

There has also been a claim of an "ashy grey leopard" with charcoal spots in India . This could be analogous to the Chinese blue tigers (maltese mutation) though it has been suggested that the animal had dust-bathed in ash from a fire, or had simply been observed in poor light. On 16/01/2009 the BBC2 Natural World documentary "The Mountains of the Monsoon" featured wildlife photographer Sandesh Kadur in the Western Ghats, India. The Western Ghats have diverse wildlife, including previously undescribed species. Ten years previously, Kadur had observed a greyish big cat in broad daylight in the high-altitude grasslands around Anamudi, the highest peak south of the Himalayas. It was large, long-tailed, had rounded ears and a uniform darkish grey colour which did not correspond to any known big cat. It was known to locals as the pogeyan ("the cat that comes and goes with the mist"). Kadur set up camera traps, but the pogeyan did not appear. Although Kadur hoped it might be a species new to science, he was realistic that a more likely identity was an aberrant form of leopard, possibly albino (he didn't mention chinchilla (cream coloured) leopards, but these are also known). The "cobweb" leopard can also appear solid grey from a distance due to the salt-and-pepper sprinkling of white hairs in the coat. The drawing of its conformation more closely resembled a lioness, which could indicate an isolated montane form of Asian lion (their known range is the Gir forest).

As well as colour variations, tail-less and short-tailed leopards have been reported. This might have been due to gene mutation, a birth defect (e.g. strangulation of the tial by the umbilical cord) or injury. The telling factor is to see whether the tail-tip has the normal black tip - if it hasn't, the tail has been lost accidentally. Inexperienced females have been know to accidentally bite off their offspring's tails (or worse a leg) during excessive grooming. In Harmsworth Natural History (1910), R Lydekker wrote of a pigmy leopard "In Somaliland occurs the smallest of all leopards (F. pardus nanopardus), in which the spotting is largely of this small solid type, while the ground-colour of the fur is greyish white. " In 2003, I heard of a longhaired leopard sighting in Africa, but received no further information or geographical information. It had the normal spotted pattern, but diffused by the longer fur (leopards normally have short, sleek fur). Since the longhair mutation is due to a recessive gene, if the apparently longhaired leopard had produced offspring then some will be carriers and the longhair mutation may turn up again.

It's worth noting that the true Amur leopard pattern is unlike that of any other leopard subspecies. The rosettes are widely spaced and of large size with very thick margins, which are usually closed. Hybrids are much like an average leopard except slightly long-haired. Their rosettes are closer together and often of smaller size, with thinner, broken margins. Pure Amur leopards have quite long legs compared with hybrids. (Long Island Ocelot Club Newsletter May/June 1991)

USEFUL GENETIC TERMS

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)
Moiser, C. 1997. The melanotic leopards of Eastern Cape, South Africa. In Downes, J. (ed) The CFZ Yearbook 1997. CFZ (Exeter), pp. 43-50.

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

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