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terça-feira, 23 de fevereiro de 2016

Types of Tigers

http://www.lions.org/types-of-tigers.html

I – Siberian tigers

img Siberian tigers are muscular, packed with large heads and powerful forelimbs. Their colors vary from orange to brown that are splashed with white areas and black stripes. Their faces have long whiskers that are longer in male tigers, featuring eyes that don rounded pupils that have been accentuated by yellow irises. The ears, however, are small and rounded with black markings that surround white areas called ocelli, which are not decorative but actually contribute to communication within the species.
The stripe pattern is different in each tiger. The markings are so unique, like human fingerprints, that researchers actually use them to identify a particular tiger.You may have heard of scientists trying to follow up what has happened to one particular tiger they have encountered before. The stripes could also be used as a means of camouflage, which is advantageous when they silently follow and pounce at their prey.
The tiger, among large cats, has the most varied size even when compared to leopards and lions.

II – Bengal tigers

img The tiger has nine subspecies. Three of these are already extinct. The historical range of tigers all across Asia is now significantly smaller. The surviving subspecies of the Pathera tigris trigris, which is popularly known by its common name, Bengal tiger can be found in Bangladesh, Bhutan, India and Nepal. It is still the subspecies with the most living individuals left, even with its mere 2,500 adult tiger population. Bengal tigers can be found in alluvial grasslands, rainforests of both the tropical and subtropical kinds, mangroves, deciduous forests and scrub forests. Male Bengal tigers can reach up to 270 to 310 centimeters (110 to 120 inches) while the females reach up to 240 to 265 centimeters (94 to 104 inches). The males are also heavier, at 175 to 260 kilograms (390 to 570 pounds), while the females weigh around 100 to 181 kilograms (220 to 400 pounds). Places also have an effect on the weight and length of the Bengal tiger, with those living in Nepal and India growing to become the largest bunch.
Project Tiger was established in India in 1972. This project was launched by those concerned about the tiger population in the hopes of ensuring that it would remain viable. This effort does not only have biological but also cultural importance. Ironically, culture is partly to blame for poaching. There is an illegal demand for tigers' body parts, especially their bones, which can be used to create Traditional Chinese medicine.
From the years of 1994 to 2009, there have been 893 cases of tiger killing as reported by the Wildlife Protection Society of India. This really shows the dangers that the tigers are always facing. There are some efforts to conserve the tiger population, however, as in the case of special conservation areas such as the one found within the Terai Arc Landscape. Such a conservation area aims to treat tigers as one meta-population or one population despite the fact that they are not exactly living together in one broad area. Another goal is for the species to have a conserved habitat that could be put forward as a rural development plan. In Nepal, a tourism and county project is aiming to not only promote the tiger population but also to regenerate forests that have been stripped down. Would these efforts be enough to save the tigers? Only time and our continued efforts will tell.

III – Indochinese tigers

img The Panthera tigris corbetti, more commonly known as the Indochinese tiger, can be found in several Asian countries such as Burma, Cambodia, Laos, China, Vietnam and Thailand. They are darker in color and smaller in size than Bengal tigers but they are not lightweights either, with their capacity to reach the maximum weight of 420 pounds for males and 310 pounds for females. Indochinese tigers prefer to live in forests in areas that are either hilly or mountainous. There aren't a lot of these tigers anymore. The government estimates the subspecies population to be at a mere 350. Even those that have been left behind are still in danger of being poached or even of starving due to the fact that their primary choice of prey, such as wild pigs and deer, are decreasing. In Vietnam, about 75% of the tigers have been poached to serve as Chinese pharmacy stock.

IV – Malayan tigers

img The Panthera tigris jacksoni, otherwise known as the Malayan tiger, can only be found in the south of the Malay Peninsula. The Malayan tiger was only recognized as a subspecies in 2004. A research conducted by Luo and others, from the Laboratory of Genomic Diversity Study (part of the United States' National Cancer Institute), came up with the new subspecies classification. There are about 500 still-living Malayan tigers but they are endangered by poaching. These are the smallest subspecies on the mainland and even the second smallest living tiger subspecies. The males average at 120 kilograms while the females average at about 100 kilograms. Note that the Malayan tiger has a cultural significance in Malaysia as it has made it to the country's coat of arms. It is also the logo of Maybank, a Malaysian bank. V- Sumatran tigers
The Panthera tigris sumatrae, commonly known as the Sumatran tiger, can only be found in Sumatra, which is an Indonesian island. If you think the other subspecies are in danger of extinction, this particular subspecies has reached the critical point. Sumatran tigers are the smallest of all living subspecies of the tiger. Adult males weigh between 100 and 140 kilograms (220 to 310 pounds) and the females weigh 75 to 110 kilograms (170 to 240 pounds). This subspecies is small because it adapts to the dense forests of Sumatra. The prey available on the island is also small, which does not do much for the Sumatran tiger's build. While the population of Sumatran tigers in the wild are around 400 to 500, which is similar to that of other subspecies, genetic testing has shown that the Sumatran tiger may develop or evolve into a different species altogether if it even manages to evade extinction. Because of this fact, there have been suggestions that the particular subspecies should be prioritized when it comes to conserving tiger subspecies.
Habitat destruction is still considered to be the main threat to the Sumatran tiger population. However, there are also records of tigers being killed by shooting near the end of the twentieth century. Those shot and killed made up 20% of the then population.

VI – South China tigers

img Panthera tigris amoyensis, also known as the South China tiger, is actually the most endangered tiger subspecies. They are even more endangered than the Sumatran tigers, which are already heavily watched by conservationists. The South China tiger has even made the list of the world's ten most endangered species. The South China tiger belongs to a group of smaller tiger subspecies, with lengths spanning from 2.2 to 2.6 meters (87 to 100 inches). The range of the length of South China tigers is true for both male and female tigers. Males have a weight range of 127 to 177 kg (280 to 390 pounds); females, on the other hand, have a weight range of 100 to 118 kilograms (220 to 260 pounds).
South China tigers were so endangered that between the years 1983 and 2007, they have not even been seen in the wild. A farmer actually had to show some photographs of a South China tiger but those photos were actually debunked as fakes. This sighting ended up becoming part of a huge scandal back in 2007.
The Chinese government made it a law to ban the killing of tigers in 1977. This could be a move that was just a little too late because of the possibility of the wild tigers being already extinct. If they are extinct then there may be less than a hundred South China tigers left, 59 of which are known to be captives. These tigers are believed to be the offspring of only six animals. This is bad news because in order for the subspecies to continue to exist, genetic diversity is needed. There are no efforts to breed the tigers to speak of right now, anyway, and no efforts to bring the tigers back to their natural habitats.
Some of the other subspecies tigers are actually a lot rarer and may even be extinct.

Extinct subspecies

I – Bali tigers

img Some tiger subspecies may still be mentioned in books but they have already been extinct as habitats continue to be destroyed. The Panthera tigris balica, which is popularly known as the Bali tiger, used to be limited to Bali, which is an Indonesian island. When it still existed, the Bali tiger was the smallest tiger subspecies, with the males weighing 90 to 100 kilograms (200 to 220 pounds) and the females weighing 65 to 80 kilograms (140 to 180 pounds). It is unfortunate that people can no longer appreciate the beauty of a Bali tiger in its compact size. The tigers have become extinct because of hunting. The last of its kind, which is an adult female, was believed to have been hunted and killed in Sumbar Kima.
Back in September 37, 1937, there was no Bali tiger left captive in West Bali. However, today, it should be noted that the tiger is still regarded with importance in Balinese Hinduism.

II – Caspian tigers

img The Panthera tigris virgata is better known as the Caspian tiger as well as under other names, such as the Hyrcanian or the Turan tiger. This tiger subspecies used to be found in sparse forests. It was also found south and west of the Caspian Sea. At least, it wast still sighted in the wild up to the early 1970s. The closest living subspecies to the Caspian tiger is the Amur tiger.

III – Javan tigers

img The Panthera tigris sondaica, otherwise known as the Javan tiger, used to live only on the island that it was named after. Sightings have been recorded up to the middle part of the 1970s. The tigers in these subspecies are bigger than Bali tigers, with the males weighing 100 to 140 kilograms (220 to 310 pounds) and the females weighing 75 to 115 kilograms (170 to 250 pounds). Sadly, the Javan tiger has no longer been sighted after 1979 when it was last seen around the Mount Betiri area.
During a Mount Halimun Salak National Park expedition back in 1990, there was no definite evidence to support that there are still living Javan tigers.

Tiger Hybrids

img We have talked about tiger subspecies that exist and also about those that are extinct. There are other species, however, which can be considered to be part of the tiger family such as the hybrids, examples of which are the Liger and the Tigon. The concept of hybrids has been around for a long time, in fact going back to the 19th century. During that time, people were interested in creating hybrids because they wanted to be able to display odd-looking creatures for profit. The ligers and tigons have been made possible because lions are already known to breed effectively with tigers, especially those from the Bengal and Amur subspecies. There was a time that it was common for these hybrids to be bred in zoos. However, the practice has now been discouraged because of the efforts to conserve species, as well as subspecies. Despite this discouragement, Chinese zoos and private menageries still breed hybrids.
The liger is a hybrid that results from the mating of a male lion and a tigress. The male lion contributes a growth-promoting gene while the tigress is not able to contribute the growth-inhibiting gene. Because of this, ligers can become a lot bigger than either of their parents at lengths of 10 to 12 feet and weights of 800 to 1,000 pounds or even more. They do, however, display the looks and behavior of both parents. As a result, a liger has both spots and stripes stamped on sandy fur. Male ligers have a fifty percent chance of growing a mane. When they actually do, their manes will not be that large, at only about half of a pure lion's.
Though the resulting liger is definitely beautiful and interesting to look at, there may be some fertility problems along the way. Male ligers are, after all, sterile even when their female counterparts are usually fertile.
The tigon, which is the result of the breeding between a male tiger and a lioness, is a less common hybrid.

Tiger Colors

Tigers may also be categorized based on colors. Looking at the colors will help people who are less familiar with subspecies.

I – White tigers

img The white tiger is produced with the help of the allele called chinchilla albinistic and is rather a rare sighting in the wild. It has, however, a very attractive color, which makes it a popular choice in zoo breeding. The color trait is recessive. So, breeding white tigers usually ends up in inbreeding. Inbreeding should be avoided because it can cause several physical defects, which include scoliosis, strabismus (crossed eyes) and cleft palates. White tigers, even the healthiest ones, have shorter lives. There have been attempts to breed white tigers to orange ones to try to fix the situation. When orange and white tigers mix, there is a mixing of subspecies.
White tigers were first bred back in the early 19th century. They can result from two parent tigers that carry the rare gene that are present in white tigers. This gene is so rare that it occurs only once every 10,000 births. White tigers are only produced when both parent tigers carry the rare gene.
Do remember that white tigers do not make up a separate subspecies. The difference it presents is only in the color. In the wild, the only tiger subspecies in the wild that have been observed to carry the white color is the Bengal tiger. Even all the white tigers that have been held captive are partly Bengal in subspecies. It is believed that the rare recessive gene that carries the white color comes from Bengal tigers only. Scientists have not yet been able to delve further into the reason for this.
There are a few misconceptions about the white tiger. Some believe that the white tiger is more endangered compared to the species as a whole. It is also wrongfully believed that white tigers are albinos, which may have been an old misconception considering the fact that their scientific name comes with the word "albinistic". Pigment, after all, exists in the stripes and the blue eyes of the white tiger but in albinos of whatever species.

II – Golden tigers

img Another recessive gene can result into an interesting "golden" hue. The color is sometimes called "golden tabby" and also sometimes called "strawberry". Golden tigers actually have gold-colored fur, with pale orange stripes and supported by strong but pale-colored legs. They have thicker fur than what is usual for tigers. As of the last count, there are only around 30 golden tigers that are held captive.
Golden tigers, like white tigers, are also part Bengal. In fact, some of them come with the white tiger gene. So, it is possible that when two golden tigers mate, they can end up producing a white tiger with no stripes. Just like the white tiger, the golden tiger is also larger than the average Bengal tiger.

III – Tigers with other colors

Other colors of tigers have been reported. There have been reports of a black tiger but none of these are authenticated except perhaps a Chittagong dead specimen back in 1846. Blue or slate-colored tigers have been heard of but not really confirmed. These tigers are called Maltese tigers. Another unconfirmed tiger color is predominantly black. If such a tiger exists, it may be a mutation instead of a separate, distinct species.

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