|Female (left) and male (right) ligers at Everland amusement park in South Korea|
The liger is a hybrid offspring of a male lion (Panthera leo) and a female tiger (Panthera tigris). The liger has parents in the same genus but of different species. The liger is distinct from the similar hybrid called the tigon, and is the largest of all known extant felines. They enjoy swimming, which is a characteristic of tigers, and are very sociable like lions. Notably, ligers typically grow larger than either parent species, unlike tigons.
The history of lion-tiger hybrids dates to at least the early 19th century in India. In 1798, Étienne Geoffroy Saint-Hilaire (1772–1844) made a colour plate of the offspring of a lion and a tiger. The portmanteau "liger" was coined by the 1930s.
In 1825, G. B. Whittaker made an engraving of liger cubs born in 1824. The parents and their three liger offspring are also depicted with their trainer in a 19th-century painting in the naïve style.
Two liger cubs born in 1837 were exhibited to King William IV and to his successor Queen Victoria. On 14 December 1900 and on 31 May 1901, Carl Hagenbeck wrote to zoologist James Cossar Ewart with details and photographs of ligers born at the Hagenbeck's Tierpark in Hamburg in 1897.
In Animal Life and the World of Nature (1902–1903), A. H. Bryden described Hagenbeck's "lion-tiger" hybrids:
It has remained for one of the most enterprising collectors and naturalists of our time, Mr. Carl Hagenbeck, not only to breed but to bring successfully to a healthy maturity, specimens of this rare alliance between those two great and formidable Felidae, the lion and tiger. The illustrations will indicate sufficiently how fortunate Mr. Hagenbeck has been in his efforts to produce these hybrids. The oldest and biggest of the animals shown is a hybrid born on the 11th May 1897. This fine beast, now more than five years old, equals and even excels in his proportions a well-grown lion, measuring as he does from nose tip to tail 10 ft 2 inches in length, and standing only three inches less than 4 ft at the shoulder. A good big lion will weigh about 400 lb [...] the hybrid in question, weighing as it does no less than 467 lb, is certainly the superior of the most well-grown lions, whether wild-bred or born in a menagerie. This animal shows faint striping and mottling, and, in its characteristics, exhibits strong traces of both its parents. It has a somewhat lion-like head, and the tail is more like that of a lion than of a tiger. On the other hand, it has no trace of mane. It is a huge and very powerful beast.
In 1935, four ligers from two litters were reared in the Zoological Gardens of Bloemfontein, South Africa. Three of them, a male and two females, were still living in 1953. The male weighed 340 kg (750 lb) and stood a foot and a half (45 cm) taller than a full grown male lion at the shoulder.
Although ligers are more commonly found than tigons today, in At Home In The Zoo (1961), Gerald Iles wrote "For the record I must say that I have never seen a liger, a hybrid obtained by crossing a lion with a tigress. They seem to be even rarer than tigons."
Size and growth
The liger is often believed to represent the largest known cat in the world. Males reach a total length of 3 to 3.6 m (9.8 to 11.8 ft), which means that they rival even large male lions and tigers in length. Imprinted genes may be a factor contributing to the large size of ligers. These are genes that may or may not be expressed on the parent they are inherited from, and that occasionally play a role in issues of hybrid growth. For example, in some dog breed crosses, genes that are expressed only when maternally-inherited cause the young to grow larger than is typical for either parent breed. This growth is not seen in the paternal breeds, as such genes are normally "counteracted" by genes inherited from the female of the appropriate breed.
Other big cat hybrids can reach similar sizes; the litigon, a rare hybrid of a male lion and a female tigon, is roughly the same size as the liger, with a male named Cubanacan (at the Alipore Zoo in India) reaching 363 kg (800 lb). The extreme rarity of these second-generation hybrids may make it difficult to ascertain whether they are larger or smaller, on average, than the liger.
It is wrongly believed that ligers continue to grow throughout their lives due to hormonal issues. It may be that they simply grow far more during their growing years and take longer to reach their full adult size. Further growth in shoulder height and body length is not seen in ligers over six years old, as in both lions and tigers. Male ligers also have the same levels of testosterone on average as an adult male lion, yet are azoospermic in accordance with Haldane's rule. In addition, female ligers may also attain great size, weighing approximately 320 kg (705 lb) and reaching 3.05 m (10 ft) long on average, and are often fertile. In contrast, pumapards (hybrids between pumas and leopards) tend to exhibit dwarfism.
Hercules, the largest non-obese liger, is recognised by the Guinness Book of World Records as the largest living cat on Earth, weighing 418.2 kg (922 lb). Hercules was featured on the Today Show, Good Morning America, Anderson Cooper 360, Inside Edition, and in a Maxim article in 2005, when he was only three years old and already weighed 408.25 kg (900 lb).
Shasta, a ligress (female liger) was born at the Hogle Zoo in Salt Lake City on 14 May 1948 and died in 1972 at age 24. Nook died in 2007, at 21 years old. Hobbs, a male liger at the Sierra Safari Zoo in Reno, Nevada, lived to almost 15 years of age before succumbing to liver failure and weighed in at 450 kg (992 lb). This liger was born in 1943 and died in 1960. South Africa still has two ligers at its one zoo at Bloemfontein.
The fertility of hybrid big cat females is well documented across a number of different hybrids. This is in accordance with Haldane's rule: in hybrids of animals whose sex is determined by sex chromosomes, if one sex is absent, rare or sterile, it is the heterogametic sex (the one with two different sex chromosomes e.g. X and Y).[clarification needed]
According to Wild Cats of the World (1975) by C. A. W. Guggisberg, ligers and tigons were long thought to be sterile; however, in 1943, a fifteen-year-old hybrid between a lion and an 'Island' tiger was successfully mated with a lion at the Munich Hellabrunn Zoo. The female cub, though of delicate health, was raised to adulthood.
Ligers have a tiger-like striped pattern that is very faint upon a lionesque tawny background. In addition, they may inherit rosettes from the lion parent (lion cubs are rosetted and some adults retain faint markings). These markings may be black, dark brown or sandy. The background color may be correspondingly tawny, sandy or golden. In common with tigers, their underparts are pale. The actual pattern and color depend on which subspecies the parents were and on how the genes interact in the offspring.
White tigers have been crossed with lions to produce "white" (actually pale golden) ligers. In theory, white tigers could be crossed with white lions to produce white, very pale or even stripeless ligers. There are no black ligers. Very few melanistic tigers have ever been recorded, most being due to excessive markings (pseudo-melanism or abundism) rather than true melanism; no reports of black lions have ever been substantiated. As blue or Maltese tigers probably no longer exist, gray or blue ligers are exceedingly improbable. It is not impossible for a liger to be white, but it is very rare.
Keeping the two species separate has been standard procedure. However, ligers have occurred, and do occur, by accident in captivity. Several AZA zoos are reported to have ligers. The USA holds the greatest population of around 30 ligers. China holds about 20 ligers. There are a few countries worldwide that hold a few, but probably less than 100 exist worldwide. 
Co-occurrence of parental species
As with the tigon, the liger exists only in captivity. Historically, the Asiatic lion and the Bengal tiger co-occurred in some Asian countries, and there are legends of male lions mating with tigresses in the wilderness, or of ligers existing there.
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- Largest living cat
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- Largest cat hybrid
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