MUTANT BIG CATS 2

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. White tigers and white lions are uncommon in the wild as they lack normal camouflage. 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 been reported. 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 e.g. the blotched King Cheetah or an normally coloured individual may have anomalous black patches (mosaicism) or white patches (partial albinism). Rufism refers to the richness of the red colour in tawny-coated cats.

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.

Some of the information here is drawn from "Mystery Cats of the World" and assorted articles by Karl Shuker. I am grateful to Paul McCarthy for researching and providing extensive material, information and corrections on white lions and white tigers and to Kevin Chambers of the Zoological Animal Reproduction Center for further information on white lions.

SERVAL MUTATIONS

The Serval (officially described in 1776) is a medium-sized, long-limbed African wild cat with large, upright ears and a tawny-yellow coat marked with large black blotches and spots. Servals are usually golden with black spots. The serval has three color morphs: melanistic, brown (usual) and white and two patterns: spotted and freckled. There are also reports of servals with abnormally dark brown base colours.

In 1839, W Ogilby documented a small-spotted Serval native to moist savannah zone in Sierra Leone, Guinea, and other parts of western Africa. He called it the Servaline. Instead of large spots, the Servaline was speckled with tiny dots and from a distance it appeared to be unpatterned and uniform in colour. It was regarded as a separate species (F servalina), supported by claims that there were no intermediate types of spotting - only large spots or freckles - and claims that Servalines were smaller than spotted Servals.

In Harmsworth Natural History (1910, chief contributors R Lydekker, Sir H Johnston & Prof JR Ainsworth-Davis) p399: “In East Africa the serval inhabits the grassy plains at the foot of Mount Kilimanjaro, where it is not uncommon; and it also ranges to an elevation of five thousand feet or more on the flanks of that mountain. At that elevation a black specimen has been obtained; and since the natives have a separate name for this black phase, it must be comparatively common. In a black skin from South Africa in the British Museum the spots are distinctly visible when the skin is viewed in certain lights, as, indeed, is corroborated by the fact that a number of such skins have been secured. The smaller spotted serval (F servalina) seems to be a distinct species.”

In 1915, a tribesman from Sierra Leone showed two kittens, one a Serval and the other a Servaline, that he claimed were from the same litter. His claim was dismissed by western experts since he had no independent testimony. Some years later, Colonel CRS Pitman, a Ugandan game warden, examined a collection of serval and servaline pelts in Northern Rhodesia (modern day Zambia). Pitman found that they formed a continuous sequence ranging from large spotted through intermediate forms to speckled. This proved that the Serval and Servaline were two extremes of a whole range of coat patterns. A selection of skins were sent to the Natural History Museum in London and the Servaline was reclassified as a colour form of Serval. The term Servaline is still sometimes used to indicate a Serval with very fine or almost indistinct spots.

Melanistic (black) servals are relatively common in the Aberdare mountains of Kenya. Most Aberdare servals are black and this may be an adaptation to help retain body heat in a cold mountainous area. Melanism is also associated with isolation and inbreeding. The base color of the pelt is darkened to a grey-brown so deep that the black spots are barely visble. As with other melanistic big cats, the larger blotches may be visible at some angles of light. The white flashes on the back of the ears are dulled to yellowish-brown (if present). Guggisberg reported black servals on the moorlands of the Aberdare Mountains at 9800 ft (3000 metres) and they have also been reported from Mount Kenya, the Mau Forest, the Cheringani Hills and Kilimanjaro. Melanistic servals are also reported from the Usambara Mountains in Tanzania and in hilly country near Nuu, Ukamba.

White servals are white or nearly white, sometimes with golden patches and have pale beige or silvery grey spots. The eyes are pale blue or green. They grow up to 20% larger than normally coloured servals but are said to have delicate health and probably short lifespans. This is similar to white Bengal tigers which grow bigger than normal coloured Bengal tigers but are less healthy due to inbreeding. It is also reported that female white servals die as kittens and have never survived beyond 2 weeks old (possibly the mutation is on the X chromosome and is lethal if 2 copies are inherited). The colour mutation is claimed to be not albinism though there are different forms of albinism (for example, the Siamese cat is due to a form of albinism), some of which are due to inability to make certain enzymes. Since these enzymes have other uses in the body apart from pigment, this could account for the health problems and the early mortality of females with the mutation.

White servals have never been documented in the wild. In captivity, there have been 4 male white servals and one male white-footed serval; there may be others living as pets. The facility holding most of these white servals had no plans to breed any more. Frosty, described as a "white-footed serval" was born in January 1995 into the pet trade. Kongo and Tonga were born in May 1997 to a pet serval and developed silvery grey spots as he matured. Kongo died in 2004 following a severe reaction to hay bedding. Pharoah was born to a pet serval in April 1999 and has some dark yellow and black markings. A white serval was born and died at the age of two weeks in Canada in the early 1990s while yet another is owned by a family living in Regina, Saskatchewan, Canada. The mutation possibly still exists in pet servals and might appear again. The colour could be perpetuated (e.g. in zoos) by breeding the white males to normal (tawny) females. Assuming that the mutation is recessive, the offspring would be tawny coloured carriers of the white mutation. Breeding two carriers together would result in some white offspring. Unfortunately this would also result in potentially unwanted tawny servals, of whom only two thirds would carry the mutation. White servals have not been reported in the wild. True (pink-eyed) albinos have not been recorded.

In addition to albino and spotted "white" servals, piebald servals have been observed. These had a similar pattern of markings to a tuxedo cat: belly, lower legs, tail-tip, chest and chin.

The servaline was once considered to be a separate species to the serval. It is now recognised as a variant pattern. Instead of large well defined markings, the servaline has smaller, but more numerous, markings (freckles) which provides better camouflage in some habitats. As with cheetahs and king cheetahs, both types can appear in a single litter. Studies indicate that black servals and freckled servalines (which are also darker in overall tone) come from moister areas. The servaline form occurs in dense vegetation and secondary forests, while the spotted serval is found in grasslands and open savannahs. The servaline is also said to be a little smaller than the bolder spotted form.

Savannah (serval x domestic cat) breeders are reproducing the white form in their breed by introducing the silver gene into the hybrids; though not the same as the wild serval mutation it resembles it closely. Small spotted "servaline type" hybrids have also been bred. Black Savannahs are being produced crossing servals with melanistic Bengals (derived from Asian Leopard Cat x domestic hybrids). At least one melanistic serval is currently owned as a pet. Savannahs will allow serval enthusiasts to own a domestic cat with the wild appearance.

 

CARACAL MUTATIONS

Melanistic individuals are relatively common. The normal colour is tawny or golden with black-tufted ears. It is sometimes known as the Desert Lynx or Caracal Lynx. Black Caracals have been reported from Uganda and from Kaffraria, South Africa. A case of dwarfism has been reported in a captive bred Caracal.

Above: Two different colours of caracal. Photo by Mindy Stinner, Conservators Center, Inc.

 

OCELOT MUTATIONS

Red (erythristic) ocelots have been recorded. These represent non-extension of the black gene, changing the normal black markings to red.

JUNGLE CAT MUTATIONS

Black (melanistic) jungle cats are known and their melanism appears to be due to a dominant gene. A pair of black Jungle cats in Cincinnati zoo had both black and normal coloured offspring. Black jungle cats have silver-tipped fur and this colour has been introduced into the Chausie (jungle cat x domestic hybrid breed) using melanistic jungle cat sires.

ASIAN LEOPARD CAT MUTATIONS

In 2002, Mr Musa Kiana of Chelmsford, England photographed an albino "Jungle Cat" in a marshy region near a remote Bengali village on the border between India and Bangladesh. He took 11 pictures of the albino cat which has no pigmentation except for white and pink. Its eyes are a deep red. Photos of the cat were sent to Colchester Zoo experts and also to London Zoo and University of Cambridge for comments. At first it was thought to be a juvenile white tiger. Musa wrote to me on 11th August 2002 to say that the cat had been confirmed by Colchester Zoo as a true albino cat, but the species had not been identified (hence it has been named after his Norwegian female friend 'Gunvor'). His main concern is the wellbeing of the albino cat which is currently in a small cage in a back garden, somewhere in the Indian sub-continent. Its location is secret because of the risk of bounty hunters and thieves.

Musa tried to get support for a rescue bid so that the cat can be kept in more suitable conditions and no longer at risk. He has been unable to get any support or interest from UK based charities and may have to sell the photos (something he had hoped not to do) in order to fund a rescue effort himself. There has been little interest from experts in the UK and really needs the attentions of cryptozoologists to identify the cat's species. He writes, "I do still believe it's the only known pure albino in the world and the most beautiful creature I have had the pleasure of seeing, but it does need proper care and attention, which few out in that region have the know how or the ability." In August 2002 I was privileged to meet Musa and view the Gunvor photographs in the hope of working out what the albino cat is not as much as what it might be.

The albino is approximately 46 inches long and stands 24 inches tall. It is male and approximately 3 years of age (judging by dentition) and had been in captivity for several months. It was able to survive despite its striking colouration - either by nocturnal hunting or by scavenging from the local village(s). The most striking feature - and the greatest problem in identification - is the colour. It is a true albino with pink eyes which reflected the camera flash very well (not the usual green-eye associated with cats). The nose and mouth are pink and the skin of the ears is pink. It is possible to distinguish its pale pink skin in many areas through the white fur. Although wild, it is said to tolerate the approach of its keeper.

The absence of any pattern (not even ghost markings) made it hard to identify a species (Jungle Cat [F chaus] or Leopard Cat [F bengalensis]). On August 19th, 2002, Musa met with a senior member of staff at the University of Cambridge, Dr Adrian Friday, University Lecturer and Curator of Vertebrates (University Museum of Zoology) who confirmed it to be a true albino Leopard Cat, rather than a Jungle cat. Because the gene for albino is carried as a recessive there is a chance it is still in the population of whichever species Gunvor represents and may occur again. Since Gunvor is a mature male, there is an excellent chance that he has bred and passed on the albino gene.

The Asian Leopard Cat is the wild parent of the Bengal breed; albino Bengal cats have occurred. An erythristic (red/golden) leopard cat has also occurred.

In March 2012, The Times Of India Kolkata described a "mystery cat" in the Sunderbans tiger reserve. Forest officers came across a small, black cat with a long tail spotted in the camera traps in Raidighi. There were no records of such a cat and although it resembled a small version of the black leopard, leopards have not been recorded in the region since 1931. Initially, experts believed it might be a new species of the wild cat with similarities to the fishing cat, leopard cat or marbled cat. After discussions with other carnivore experts, it was identified as a melanistic Leopard Cat on the basis of its tail length: a fishing cat's tail is about a third the length of its body, whereas a leopard cat's tail is about half the length of its body.

 

GEOFFROY'S CAT MUTATIONS

Geoffroy's Cat is a little larger than a domestic cat and is usually spotted. Melanistic Geoffroy's cats have occurred.

 

INDIAN (TEMMINCK'S) GOLDEN CAT MUTATIONS

Temminck's Golden Cat (F temmincki), or Asiatic/Indian Golden Cat, also has variable markings. One of its subspecies, Fontainier's Cat, a large form found in Burma and Tibet, has markings similar enough to the Asian leopard Cat that it was once considered a subspecies of Asian Leopard Cat instead. Basel Zoo had a melanistic Temminck's Cat (Asiatic Golden Cat).

Melanistic individuals have been reported.

 

 

Photo: http://www.bigcats.org

There is another species of Golden Cat called the African Golden Cat (F aurata). In 1827, Dutch zoologist Professor CJ Temminck described a grey (silver) cat he called F celidogaster and considered a different species to the familiar tawny-coloured African Golden Cat. The Golden and Grey (Silver) versions were classed as separate species until June 1906 when London Zoo's newly arrive Golden Cat moulted its tawny coat and grew a grey coat in its place. It turned out that the African Golden Cat had two colour phases. In addition, African Golden Cats have variable markings and western versions are heavily spotted while eastern specimens are generally plain.

BOBCAT MUTATIONS

Photo: http://www.bigcats.org

 

Melanistic (black) bobcats have been reported. A stuffed melanistic bobcat is on display at Totemin Zoo in Wilmington North Carolina, albeit in bad repair. It apparently dates from the 1970s and was collected in Florida. Melanistic bobcats have not been reported outside of Florida. Some details was lost during taxidermy and http://www.bigcats.org report that the faint markings do not follow the common bobcat pattern, the ear furnishings are different and there is no "beard" or ruff. This does not rule out melanism, nor does it rule out hybridisation with domestic cats.

According to Fred A Ulmer Jr in "Melanism in the Felidae, with Special Reference to the Genus Lynx" (Journal of Mammalogy, Vol. 22, No. 3 (Aug., 1941), pp. 285-288), on April 18, 1939, Vincent Nelson and J Townsend Sackett live-trapped a melanistic male Florida bobcat (Lynx rufus floridianus) in Martin County, Florida, 14 miles above the mouth of the Loxahatchee River. An experienced trapper, Martin had caught many bobcats, but had not previously seen a black one. The black bobcat was secured by Sackett for the Zoological Society of Philadelphia and exhibited at their Zoological Gardens from late April through to August 3, apparently dying of feline infectious enteritis (described as distemper by Ulmer). Its skin and skull went to the collection of the Acadamy of Natural Sciences of Philadelphia (specimen no 19842) where Ulmer later examined the skin. In January 1940, Nelson live-trapped a melanistic female bobcat in the same region. This was caught about 2 miles from the first specimen, in swampy jungle lose to the confluence of Kitachen Creek and Loxahatchee (or Jupiter) River. Dr Raymond L Ditmars obtained the melanistic female for the Bronx Park Zoo.

Ulmer examined the skin of the Philadelphia specimen and described it as follows (it should be noted that melanistic fur frequently pales to dark brown during the preservation process): "The Academy specimen, upon close examination, is far from black. The most heavily pigmented portions are the crown and dorsal area. In most lights these appear black, but at certain angles the dorsal strip has a decidedly mahogany tint. The mahogany coloring becomes lighter and richer on the sides. The underparts are lightest, being almost ferruginous in color. The chin, throat and cheeks are dark chocolate-brown, but the facial stripes can be clearly seen. The limbs are dark mahogany. In certain lights the typical spot pattern of the Florida bobcat can be distinctly seen on the sides, underparts and limbs. The Bronx Park animal appears darker and the spots are not visible, although the poor light in the quarantine cage may have been the reason. Numerous white hairs are scattered through the dark dorsal strip in both animals. The normal bobcat's dorsal area is similarly sprinkled with white hairs, but in the light, grizzled pelage they are scarcely noticeable. A small patch of white hair occurs in the inguinal region of the Academy's specimen. The Bronx individual has a larger white inguinal patch."

Their whiskers were slightly darker than those of normally pigmented bobcats, but their facial ruffs were short and inconspicuous which, along with their sleek black fur, made them resemble large domestic cats (this absence of ruffs, along with the colouration and white patches is also suggestive of introgressive hybridisation with domestic cats in the same way that black Kellas cats have arisen from hybridisation between Scottish wildcats and domestic cats carrying the non-agouti gene)

There have long been accounts of Black Florida Panthers the size of a Labrador dog. One such cat was captured in 2007 in Martin County, Florida and researchers at the Busch Wildlife Sanctuary were able to identify it. The "Black Panther" trapped in a back garden where it had killed domestic poultry turned out to be a 16 lb melanistic bobcat (black all over apart from a white spot on the belly). There have 13 previous confirmed (killed, captured or photographed) melanistic bobcats in south and south central Florida since 1939; most having been in the region of the Loxahatchee River and St Lucie Canal. The 2007 case was in the environs of the St Lucie Canal. After running DNA tests to ensure the animal is fully and officially documented, the black bobcat will be released back into the wild. It was about 2 years old and male, making it likely the recessive melanism gene will be perpetuated the local bobcat population.

Bobcats are normally tawny/rufous with black markings though blue-grey bobcats and red bobcats have also have been reported. There have been increasing numbers of reports of albino bobcats.

LYNX MUTATIONS

Melanistic (black) lynxes have been reported.

In 1938, a blue lynx pelt was donated to the US National Museum by Mrs Charles D. Walcott. The pelt came from an animal trapped somewhere in Alaska). In place of the normal fawn colour, this pelt was bluish-grey all over. It exhibited the pale inner limbs and belly found in normal lynxes, but instead of the normal black tail-tip and ear-tufts, the specimen had a darker blue-grey tail-tip and ear-tufts. On investigation, it turned out that the animal had no black colouration at all. This is the same as the dilute mutation in domestic cats - normally black areas are instead expressed as bluish-grey (the chinchilla mutation would have resulted in black markings on a silvery background). Enquiries were made to the fur trade; furriers stated that the mutant grey form was observed once or twice in every thousand lynx skins.

A piebald lynx was released in Colorado as part of a reintroduction scheme. The pattern corresponds closely to the bicolour pattern in domestic cats - white facial markings, white legs, white chest and belly and might be due to a similar gene mutation in the lynx rather than partial albinism. If so, the white spotting gene can be expected to manifest in the lynx's offspring.

A drab blue lynx was noted in 1892, together with a yellow lynx. The yellow lynx indicates a mutation where black pigment is replaced with yellow or red (non-extension of the black gene). The lynx below is almost white with a black tail-tip and was caught in Tibet; its body is displayed at the Rothchild Zoological Museum in Tring, England. The yellowish cast is due to the lighting used (to prevent specimens from discolouring). A bicolour lynx was released in Colorado, USA in a reintroduction programme; it was grey with white legs and chest and a white blaze down its nose.

The construction of the Alqueva dam in Eastern Portugal creates Europe's biggest reservoir in a known Iberian Lynx Territory. As the lynx population becomes more fragmented by human-made obstacles, the lynx groups become inbred and inbreeding depression occurs. The loss of genetic diversity means some fur patterns have been disappearing while melanistic lynx have emerged due to recessive genes doubling up.

 

CLOUDED LEOPARD MUTATIONS

There have been pure black specimens reported of the Clouded Leopard. In spring 1946, the skin and lower jaw of a black Clouded Leopard were obtained in Borneo. Another black Clouded Leopard was reported on Mount Matang (undated, but possibly around the same time). Six reports of melanistic Clouded Leopards were made in 1982 in Sabah. In 1986, there were three sightings of black Clouded Leopards in Sarawak, plus one sighting from Sabah. There have been no live captures of melanistic Clouded Leopards or recent skins (for DNA testing) to prove this issue beyond doubt.

FISHING CAT MUTATIONS

An albino Fishing Cat has been reported.

JAGUARUNDI MUTATIONS

In South America, there are two colour morphs of Jaguarundi. The red form was known as the Jaguarundi and the grey form was considered a separate species and called the Eyra.

MELANISTIC CATS MAY BE MORE HEALTHY?

"The Smithsonian Answer Book: Cats" has an illustration of a black Geoffroy's cat and stated that genes for blackness in cats may provide resistance from viral infections. The black gene in domestic cats is different from the black gene in jaguars and jaguarundis (black jaguarundis may be supplanting the red form). Both genes are different from black genes in 5 other species. The same gene is involved in jaguars and jaguarundis, but the mutation is different in each. The melanism mutation appears to have evolved at least 4 times and possibly 9 times. A viral epidemic may explain the prevalence of black leopards in Java and Malaysia, and may also explain why the Aberdares, Africa, has so many black leopards and black servals.

Studies in 2003 suggested that black fur is linked to disease resistance and not merely to altitude (black absorbs more heat and has been considered a high altitude adaptation). The disease resistance theory may explain why the gene persists even though pure black individuals may be disadvantaged by it. It may confer immune advantage to the normally patterned carriers (in recessive gene forms of melanism). Melanism has evolved separately many times in different species of cat. One study suggested it was found in only 11 out of 37 species, others list additional species exhibiting the trait (18 species). There are no confirmed melanistic pumas. All "black tigers" to date have been due to a condition called abundism.

Scottish Wild cat
Indian (Temmincks) Golden Cat
African Golden Cat
Jungle cat (dominant gene melanism, silver tipped)
Jaguar (dominant gene melanism)
Leopard ("black panther")

Cheetah
Caracal
Serval
Lynx
Bobcat
Jaguarundi

Geoffroy's cat
Clouded leopard
Ocelot
Pampas cat (Cincinnati zoo)
Oncilla
Kodkod

Dark fur may have a survival benefit beyond camouflage since the mutations which lead to a black coat are in the same gene family as those involved in human diseases like AIDS. Melanistic cats may therefore have better resistance to disease than cats with "normal" colour coats (Eduardo Eizirik & Stephen O'Brien, US National Cancer Institute, Maryland).

Melanism is due to changes in the "agouti" gene which controls blackness (due to bands of colour along the hair shaft).Cats with normal agouti genes have ticked or banded hairs.  Cats with 2 copies of the mutated agouti gene have solid colour hairs. In wild species this causes melanism (in domestic cats other genes affect the colour e.g. black, grey, brown). In most cat species, the gene for melanism is recessive to that for normal colour. In jaguars, melanism is a dominant gene. The gene is actually incompletely dominant and cats with 2 copies of the gene (homozygotes) are darker than those with only one copy (heterozygotes). Studies showed that black cats also had changes to a connected gene known as MC1R. MC1R is a member of a family of genes which includes the human gene CCR5. CCR5 codes for a protein on the cell membrane and this protein is a key allowing in various viruses, including HIV. Possibly black cats are less susceptible to viral infection and this, rather than better camouflage, is the evolutionary advantage.

ALBINISM AND HEALTH

Albinism is linked to poor health for a variety of reasons. Many albino animals appear to have poor immune systems compared to normally patterned individuals. This may simply be the converse of the finding that melanism is linked to greater disease resistance i.e. lack of melanism is linked to poor disease resistance. The lack of pigment makes them prone to skin cancer as they have no pigment to protect them from the sun's UV rays. The lack of pigment in the eyes makes them photo-sensitive - not a problem in a night-time hunter, but it is a handicap for a day-time hunter.

GREEN CATS?

There have, from time to time, been reports of green big cats. A green lion was reported by a prospector in the forests of western Uganda (reported 1962, but actual sighting is undated). Green fur colour in mammals is most often due to contaminants on the fur e.g. algae (where the cat has swum in algae rich water) or copper patina; or even a trick of the light - sunlight filtering through green leaves can give pale animals a green cast.

 

USEFUL GENETIC TERMS

Textual content is licensed under the GFDL.

  • Hichens, W. 1937. African Mystery Beasts. Discovery (Dec): 369-373.
  • Fred A Ulmer Jr "Melanism in the Felidae, with Special Reference to the Genus Lynx" (Journal of Mammalogy, Vol. 22, No. 3 (Aug., 1941), pp. 285-288)

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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