Liger

For other uses of Liger see Liger (disambiguation).

File:Bertramliger.jpg

Liger

The liger is a cross (a hybrid) between a male lion and a female tiger. It has also been known as a lion-tiger mule. A liger looks like a giant lion with diffused stripes. Some male ligers grow sparse manes. Like tigers, but unlike lions, ligers enjoy swimming.

A cross between a male tiger and a female lion is called a tigon. According to The Tiger, Symbol of Freedom rare reports have been made of tigresses mating with lions in the wild. , "Under exceptional circumstances it has been known for a tiger to be forced into ranges inhabited by the Asian lion, Panthera leo persica, which is the same genus as the tiger. Reports have been made of tigresses mating with lions in the wild and producing offspring known as ligers. When a tiger and a lioness mate the cub is called a tigon.'" This would have referred to the Gir Forest in India where the ranges of Asiatic Lions and Bengal Tigers overlap.

History

Cuvier reported a litter of three lion-tiger "mules" born in October 1824 in England, United Kingdom to an African lion and an Asiatic tigress owned by an itinerant exhibitor and animal dealer. The parents shared a den and had mated frequently during July 1823. The cubs were exhibited to his Majesty. Cuvier presented an engraving of 2 cubs at 3 months old and observed that they would probably reach maturity. He described them as being dirty-yellow or "blanket-colour" with darker tiger-like stripes on the body and spots on the head and on parts of the body. They had lion-like heads. These appear to be the first recorded ligers.

Two of the liger cubs were painted by Geoffrey St Hilaire (1772 - 1844). In 1825, G B Whittaker made an engraving of the 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 naive style.

Two liger cubs born in 1837 were exhibited to William IV and to his successor Victoria. On the 14th of December 1900 and on the 31st of May 1901, Carl Hagenbeck wrote to zoologist James Cossar Ewart with details and photographs of ligers born at the Hagenpark 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 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 little or 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 750 lb. and stood a foot and a half 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.

Large size

A liger and its trainer, October 2005.

Ligers grow much larger than lions and slightly larger than the largest tigers, which can weigh in excess of 386 kg (850 lb). Some ligers have been estimated to weigh over 500 kg (1100 lb), over twice the size of a male lion; this is called growth dysplasia. The liger is the largest animal in the feline family Felidae.

Lions live in prides led by several adult males and have a competitive breeding strategy. The lionesses mate with several males and her cubs will have different fathers. Each male wants his offspring to be the ones to survive, but the female wants multiple offspring to survive. A male's genes promote size of the offspring to out-compete other males' offspring in the womb at the same time. Genes from the female inhibit growth so that multiple offspring survive. Tigers, however, are largely solitary and a female in heat normally only mates with one male. There is no competition for space in the womb so the male tiger's genes do not need to promote larger offspring. There is therefore no need for the female to compensate, so the offspring's growth goes uninhibited.

When a male lion mates with a tigress, his genes promote large offspring. The tigress does not inhibit the growth because she is adapted to a non-competitive strategy. Therefore the liger offspring grows larger than either parent. When a male tiger mates with a lioness, his genes are not promoting large growth of the offspring, but the lioness's genes still inhibit their growth. Hence tigons are often smaller and less robust than either parent.

Imprinted genes may be a factor contributing to liger size. These are genes that may or may not be expressed depending on the parent they are inherited from, and that occasionally play a role in issues of hybrid growth. For example, in some mice species crosses, genes that are expressed only when paternally-inherited cause the young to grow larger than is typical for either parent species. This growth is not seen in the paternal species, as such genes are normally "counteracted" by genes inherited from the female of the appropriate species.

Another possible hypothesis is that the growth dysplasia results from the interaction between lion genes and tiger womb environment. The tiger produces a hormone that sets the fetal liger on a pattern of growth that does not end throughout its life. The hormonal hypothesis is that the cause of the male liger's growth is its sterility — essentially, the male liger remains in the pre-pubertal growth phase. This is not upheld by behavioural evidence - despite being sterile, many male ligers become sexually mature and mate with females. In addition, female ligers also attain great size, weighing approximately 700 lb (320 kg) and reaching 10 feet (3.05 m) long on average, but are often fertile.

Longevity

Shasta, a ligress (female liger) was born at the Hogle Zoo in Salt Lake City on May 14th, 1948 and died in 1972 at age 24. The 1973 Guinness world records reported an 18 year old, 750 lb male liger living at Bloemfontein zoological gardens, South Africa in 1953.

Fertility

Male ligers are sterile, but female ligers are fertile and can breed with tigers (resulting in ti-ligers) or to lions (resulting in li-ligers). Ti-ligers are more tiger-like, having a greater percentage of tiger genes. Li-ligers are more lion-like, having a greater percentage of lion genes. 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 gender is determined by sex chromosomes, the heterogametic sex (the one with two different sex chromosomes e.g. X and Y) is either absent, rare or sterile.

According to Wild Cats Of The World (1975) by Guggisberg, ligers and tigons were long thought to be sterile: In 1943, however, 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, even though very delicate, was raised to adulthood.

More recently, a self-styled behavioural research program in the USA bred a female ti-liger called Lady Kali.

Vocalisation and behavior

Ligers may exhibit emotional or behavioural conflicts due to their mixed ancestry.

They inherit different or mixed vocabularies (tigers "chuff", lions roar).

They may inherit conflicting behavioral traits from the parent species. Ligers may exhibit conflicts between the social habits of the lion and the solitary habits of the tiger. Their lion heritage wants them to form social groups, but their tiger heritage urges them to be intolerant of company. Opponents of deliberate hybridization say this causes confusion and depression for the animals, especially after sexual maturity. How much of their behaviour is due to conflicting instincts and how much is due to abnormal hormones or the stress of captive conditions is not fully known.

Colors

Ligers have a tiger-like striping pattern on a lion-like 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 depends on which subspecies the parents were and on the way in which 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. A black liger would require both a melanistic tiger and a melanistic lion as parents. 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. A hypothetical procedure to breed black ligers is explained here. The blue or Maltese tiger is now unlikely to exist, making grey or blue ligers an impossibility. It is not impossible for a liger to be white, but it is very rare.

Criticism

The breeding of Ligers is often criticized because the parent species, particularly Tigers, are endangered and they would be better suited in perpetuating their own species. Also, the hybrids tend to have shorter lifespans and they are often prone to health problems.

See also

• Growth dysplasia
• Tigon
• Maltese tiger
• Panthera hybrid

References

            8 ^ Napoleon Dynamite: 2005 film, Napoleon draws a picture of a Liger

Further reading

• G Peters "Comparative Investigation of Vocalisation in Several Felids" published in German in Spixiana-Supplement, 1978; (1): 1-206.
• Courtney, N "The Tiger - Symbol of Freedom" Quartet Books, London, 1980

External links

• Liger Pictures Liger Pictures from the Animal Safari in Pine Mountain Georgia
• Zita on display at the Novosibirsk Zoo (Russia)
• Home of Hercules the liger
• Hercules the Liger at Snopes.com
• More pictures of Hercules
• Hobbs at the Sierra Safari Zoo.
• Patrick at the Shambala Preserve
• Liger cubs at Noah's Ark Zoo (German)
• Hybrid Big Cats, pages 1 and 2
• Patrick the Liger from National Geographic
• A drawing of a liger as seen in Napoleon Dynamite
• Liger Tribute
• video of liger