Ligers and Tigons

[malah777]

Liger-The liger is a hybrid cross between a male lion and a female tiger. It is denoted scientifically as Panthera tigris × Panthera leo.A liger resembles a lion with diffused stripes. They are the largest cats in the world, although the Siberian Tiger is the largest pure sub-species. Like tigers, but unlike lions, ligers enjoy swimming. A similar hybrid, the offspring of a male tiger and a female lion is called a tigon.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 Asiatic Lion, Panthera leo persica; however, this combination of species in the wild is considered highly unlikely.
Size and growth:
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 maternally-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.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. Male ligers also have the same levels of testosterone ng/dl on average as an adult male lion. In addition, female ligers also attain great size, weighing approximately 700 lb (320 kg) and reaching 10 feet (3.05 m) long on average, and are often fertile.

Longevity-18-26 years
Fertility:
While male ligers are sterile, female ligers are fertile, and they can reproduce. Because only female ligers and tigons are fertile, a liger cannot reproduce with a tigon.If a liger were to reproduce with a tiger, it would be called a ti-liger, and if it were to reproduce with a lion, it would be called a li-liger. 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, if one gender is absent, rare or sterile, it is the heterogametic sex (the one with two different sex chromosomes e.g. X and Y).According to Wild Cats of the World (1975) by C. A. W. 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, although of delicate health, was raised to adulthood.

Liger

Tigon
The Tigon or Tigron is a hybrid cross between a female lion and a male tiger. The tigon is not currently as common as the converse hybrid, the liger; however, in the late 19th and early 20th centuries, tigons were more common than ligers.
Tigons can exhibit characteristics of both parents: they can have both spots from the mother (lions carry genes for spots — lion cubs are spotted) and stripes from the father. Any mane that a male tigon may have will appear shorter and less noticeable than a lion's mane and is closer in type to the ruff of a male tiger. It is a common misconception that Tigons are smaller than lions or tigers. They do not exceed the size of their parent species because they inherit growth-inhibitory genes from the lioness mother, but they do not exhibit any kind of dwarfism or miniaturisation.The comparative rarity of tigons is attributed to male tigers' finding the courtship behaviour of a lioness too subtle and thus may miss behavioural cues that signal her willingness to mate. However, lionesses actively solicit mating, so the current rarity of tigons is most likely due to their being less impressive in size than ligers, with a corresponding lesser novelty value. A century ago, tigons were evidently more common than ligers. Gerald Iles, in At Home In The Zoo (1961) was able to obtain three tigons for Manchester's Belle Vue Zoo, but wrote that he had never seen a liger. A number of tigons are currently being bred in China.
Fertility:
In Wild Cats Of The World (1975), Guggisberg wrote that 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, although of delicate health, was raised to adulthood.Male tigons are sterile while the females are generally fertile. Because only female ligers and tigons are fertile, ligers and tigons cannot reproduce with each other.At the Alipore Zoo in India, a female tigon named Rudhrani, born in 1971, was successfully mated to an Asiatic Lion named Debabrata. The rare, second generation hybrid was called a li-tigon. Rudhrani produced seven li-tigons in her lifetime. Some of these reached impressive sizes—a li-tigon named Cubanacan (died 1991) weighed at least 800lb (363 kg), stood 52 inches (1.32 metres) at the shoulder, and was 11.5ft (3.5 m) in total length.
Reports also exist of the similar ti-tigon, resulting from the cross between a female tigon and a male tiger. Ti-tigons resemble golden tigers but with less contrast in their markings. A female tigon born in 1978, named Noelle, shared an enclosure in the Shambala Reserve with a male Siberian Tiger called Anton, in the belief that she was sterile. In 1983, Noelle produced a ti-tigon named Nathaniel. As Nathaniel was three-quarters tiger, he had darker stripes than Noelle and "spoke" tiger rather than the mix of sounds used by his mother. Being only about quarter-lion, Nathaniel did not grow a mane. Nathaniel died at age eight or nine years old due to cancer. Noelle also developed cancer and died soon after.
Tigon

[vulnera]

May 11, 2006—DNA analysis has confirmed that a bear shot in the Canadian Arctic last month is a half-polar bear, half-grizzly hybrid. While the two bear species have interbred in zoos, this is the first evidence of a wild polar bear-grizzly offspring.

http://news.nationalgeographic.com/n...rid-photo.html

http://en.wikipedia.org/wiki/Grizzly-polar_bear_hybrid

[Sandalphon]

I do not understand why they had to kill it?

[vulnera]

i dont either...

[Angelologist]

Oh no. . .why did they develop cancer, because of the “unnatural” mix? Do the lions and tigers naturally mate with each other? Or is it coerced by humans.

Those bastards killed that bear! Grrrr I hate that picture.

[Stritheil]

Originally Posted by Sandalphon

I do not understand why they had to kill it?

Since polar bears are ferocious predators, people are sometimes forced to shoot them in order to avoid being killed. However, it's illegal to kill a polar bear here in Canada except for self defense or as a result of having purchased a hunting licence, which costs thousands of dollars and requires the hunter to take along some Inuit guides, who rely on the hunters for income. The hunt also provides work for taxidermists, since most of the hunters want a polar bear rug as a souvenir of their trip.

The territorial and federal governments claim that a controlled polar bear hunt helps the bears avoid the population rise and crash that otherwise occurs naturally in many species, while providing money to the territorial government and income for Inuit guides, in a part of the world where there aren't many jobs. However, the hunt is quite controversial, and a lot of people are opposed to it.

In the case of the strange hybrid, which was in all the newspapers here in Canada, the hunter and guides were originally threatened with criminal charges for killing a bear other than the type permitted by the licence (I think the licences only permit the killing of adult male polar bears). But a biologist pointed out that it would have been impossible to tell that the bear was anything other than a polar bear while it was still alive, unless they got very close to the beastie, which might then have gotten the better of them.

Polar bears are very powerful, smart, tough and fast. I saw a video showing a polar bear covering its black nose with its paw while it snuck across the snow to ambush a scientist. The scientist would never have seen danger coming soon enough to get into his vehicle if the camera man hadn't warned him by radio about the approaching bear.

Some folks claim that the hybrid, which is likely a result of grizzlies moving further north, is one more proof of global warming, which is moving much faster near the planetary poles than anywhere else. And that the existence of the hybrid proves that polar bears, which survive mainly by hunting seals from ice flows, are now so endangered that the licenced hunts should be banned. However, the short term result of the warming trend is that the polar bear population is mushrooming, because of more ice flows in the water, as ancient glaciers break apart, and more seals living in the far north as some fish stocks move further north.

[vulnera]

thanks for the extra background info on this hunt.

i wonder if the other bears thought anything of the odd romance that resulted in such offspring, heheh...

[Stritheil]

Originally Posted by vulnera

thanks for the extra background info on this hunt.

i wonder if the other bears thought anything of the odd romance that resulted in such offspring, heheh...

The idea of a hybrid is kind of strange, since polar bears mate on ice flows during April and May, whereas grizzlies mate on land during May and June. So the breeding season of the two types of bear overlap, but their breeding habitats differ. This is the only recorded case of a polar bear-grizzly cross. Inuit elders say that when polar bears and grizzlies meet, they're usually hostile toward one another. So it must have been a real Romeo and Juliet scenario of two star crossed bears producing an offspring that was probably rejected by both types of bear. Then, after being shot and having his remains stored in a freezer for a few months while the authorities decided whether the hunter could have his trophy, which wasn't technically a polar bear, the poor critter ended up as a rug. Some bears just have no luck at all.

[Lady Dunsany]

Well maybe we should hunt the one's that killed the polar bear since they are more dangerous. There is no reason to kill the bear, it is just to justify a sick power play. I am frankly sick of seeing something so beautiful hunted down and pictures taken of the kill. It seems it was not necessary so please forgive me if I say this is BS.

[Draginvry]

Originally Posted by Angelologist

Do the lions and tigers naturally mate with each other?

Lions and tigers don't mate in the wild. It is rare that they will ever agree to share the same territory.

Even more rare, is a lion and a tiger even being in the same habitat. Like all big cats, they compete for territory. This has left the big cat species specialists for specific ecosystems.