The white panther is the common name for a white specimen of several species of cat. Zoologically speaking, the term panther is synonymous with leopard. The genus name Panthera is a taxonomic category that contains all the species of a particular group of felids. The term panther is used in some parts of North America to mean the Cougar, in South America to mean the Jaguar and elsewhere it refers to the Leopard. A white panther may therefore be a white Cougar, white Jaguar or white Leopard. Of these, white Leopards appear to be more common, although still very rare.
White panthers may be the result of albinism, leucism or the chinchilla mutation. It is a common misconception that panther means a melanistic individual. Unlike the black panther, they have not been selectively bred.
In Harmsworthington Natural History (1910), R Lydekker wrote: Far rarer than black leopards are white ones, of which but very few have been met with. As well as white Leopards, there are pale cream Leopards with pale markings and blue eyes. 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). R. I. Pocock reported a purely white skin from East Africa; the spots were only visible in reflected light.
In "The Wildlife of India", 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. This indicates a chinchilla mutation instead of albinism. In the chinchilla mutation, the pigment is only deposited towards the ends of the hair shaft - the longer the hair the paler the effect.
A wild-caught albino Leopard called Jinx was kept at the Central Park Zoo, USA between 1935-1960 and had originated from Mozambique. Descriptions suggest the markings were visible in certain light. White Leopards were apparently born at Los Angeles (USA) Wildlife Weighstation; these were leucistic i.e. white but with normally coloured eyes. They developed spots as they grew older.
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 by 5 months old. In May 1978, a pair of white Leopard cubs were born to normal (spotted) Leopards at Rome Zoo. Both had to be hand-reared. The male cub was whitish with light grey spots and died shortly afterwards due to 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.
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 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 confirmed that she has white skin, though she was also described as having spots. Blood tests on Isis and her parents were planned if she thrived and if her skin remained white. Claws 'N' Paws Wild Animal Park, Pennsylvania, USA, also claimed a white Leopard.