четверг, 5 мая 2011 г.

Tiger 3

For the first time hybrids of tigers began to appear in a XIX-th century in the zoos which owners have been interested in attraction of visitors in the institutions and increase in profit [34]. Now similar hybrids still arise in private zoos of China [35]. Hybrids between a lion and a tiger (more often the Amur and Bengalese subspecies) are known.
a hybrid of a lion and a tigress. Females лигров can give posterity that is unusual to hybrids [36]. Individuals лигров grow all life and by an old age can reach the sizes to 3 meters at length (without a tail). Unusual giantism лигра speaks that in DNA of a lion and a tigress there is a gene which is responsible for growth. At a tiger and a lioness this gene is absent [37]. In Russia лигрица contains in Novosibirsk, and since 2007, and in Lipetsk zoos.
a hybrid of a tiger and a lioness. Combine signs of both parents: can have stains from mother and a strip from the father. The mane тигонов if she appears, will be always shorter than a mane of a lion. Usually тигоны there are less than lions and tigers also weigh about 150 kg. Males тигонов are always sterile, while the female — isn't present

White tiger
The tiger has a known mutation which leads to occurrence of individuals with completely white coloring — Bengalese tigers with black-brown strips on white fur and blue eyes. Such coloring very seldom meets among wild animals, but is concerning extended in the populations containing in bondage. Frequency of occurrence of white tigers — 1 individual on 10 000 with normal coloring [39]. White tigers excellently breed in bondage. The first mentions of them carry to 1951, when one of hunters of visors of the den of a tiger found him white тигрёнка. Subsequently the given tiger has been crossed to a female of usual coloring who has given birth to a four тигрят usual окраса. Later the white tiger has been crossed to one of the white daughters at whom were born 3 тигрёнка, 2 from which were white. All white tigers containing in bondage are descendants of one individual . Now in world zoos contains about 130 white tigers. And though on their skin the dark strips are clearly visible, one of errors is the opinion that white tigers are albinos.

Gold tiger
So-called gold version — the most seldom meeting change of coloring caused рецессивным by a gene. The first mentions of a meeting with gold tigers in the wild nature are dated the beginning of the XX-th century. The theory has originally been put forward that occurrence of the given type of coloring gradually developed in small group of the tigers living in areas rich clay soils, and unusual color served him as an additional camouflage at hunting. The theory remains unsubstantiated. However инбридинг the small isolated group of tigers could affect occurrence of the given type окраса if one of tigers, carriers рецессивного a gene gold окраса, was crossed to own posterity, as well as has occurred in bondage.
So-called gold version of a tiger. A zoo of Buffalo
At present in bondage contains about 30 individuals with the given type окраса. As well as the white tigers, all gold tigers containing in bondage have mainly Bengalese origin, but "are genetically polluted" by genes of partially Amur white tiger by name of Tony who is the general ancestor almost all white tigers in the North America. The assumption that the given coloring has appeared by crossing of the Amur and Bengalese tigers, is a popular belief.
Other variations
It was informed also on existence among Bengalese tigers меланистов with smoky or completely black fur. Also there are messages on occurrence of tigers with livid окрасом (a so-called Maltese tiger). The given types of coloring are caused by unstable mutations.

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