Wednesday 5 October 2011
my friends
I have many friends.And I also have many specials friends.Especially my SMSTJ friends and friends from Thialand.Although I had newly met them,but Ithink they have a very special bond with me.Thats all from now
Tuesday 4 October 2011
Tiger 3
Knowing their physical characteristic , taxamony and e
Video from the Disney's Animal KingdomThe oldest remains of a tiger-like cat, called Panthera palaeosinensis, have been found in China and Java. This species lived about 2 million years ago, at the beginning of the Pleistocene, and was smaller than a modern tiger. The earliest fossils of true tigers are known from Java, and are between 1.6 and 1.8 million years old. Distinct fossils from the early and middle Pleistocene were also discovered in deposits from China, and Sumatra. A subspecies called the Trinil tiger (Panthera tigris trinilensis) lived about 1.2 million years ago and is known from fossils found at Trinil in Java.[20]
Tigers first reached India and northern Asia in the late Pleistocene, reaching eastern Beringia (but not the American Continent), Japan, and Sakhalin. Fossils found in Japan indicate that the local tigers were, like the surviving island subspecies, smaller than the mainland forms. This may be due to the phenomenon in which body size is related to environmental space (see insular dwarfism), or perhaps the availability of prey. Until the Holocene, tigers also lived in Borneo, as well as on the island of Palawan in the Philippines.[21]
Siberian tigerTigers typically have rusty-reddish to brown-rusty coats, a whitish medial and ventral area, a white "fringe" that surrounds the face, and stripes that vary from brown or gray to pure black. The form and density of stripes differs between subspecies (as well as the ground coloration of the fur; for instance, Siberian tigers are usually paler than other tiger subspecies), but most tigers have over 100 stripes[citation needed].
The pattern of stripes is unique to each animal, these unique markings can be used by researchers to identify individuals (both in the wild and captivity), much in the same way that fingerprints are used to identify humans. It seems likely that the function of stripes is camouflage, serving to help tigers conceal themselves amongst the dappled shadows and long grass of their environment as they stalk their prey. The stripe pattern is also found on the skin of the tiger. If a tiger were to be shaved, its distinctive camouflage pattern would be preserved.
Like other big cats, tigers have a white spot on the backs of their ears. These spots, called ocelli, serve a social function, by communicating the animal's mental state to conspecifics in the gloom of dense forest or in tall grass.
SkeletonTigers have the additional distinction of being the heaviest cats found in the wild.[22] They also have powerfully built legs and shoulders, with the result that they, like lions, have the ability to pull down prey substantially heavier than themselves. However, the subspecies differ markedly in size, tending to increase proportionally with latitude, as predicted by Bergmann's Rule.
The tiger are the most variable in size of all big cats, even more so than the leopard and much more so than lions.[23] Large male Siberian Tigers (Panthera tigris altaica) can reach a total length of more than 3.5 m (11.6 ft) "over curves" (3.3 m or 10.9 ft "between pegs") and a weight of 306 kilograms (675 lbs).[24] This is considerably larger than the sizes reached by island-dwelling tigers such as the Sumatran, the smallest living subspecies, with a body weight of only 75–140 kg (165–310 lbs).[24] Depending upon subspecies tigers may be 1.4–2.8 m (4.6–9.2 ft) long from the nose to the base of the tail, while the tail may add a further 0.6–1.1 m (2–3.6 ft).[25][26] At the shoulder, tigers may variously stand 0.7 to 1.22 m (2.3 to 4.0 ft) tall.[27][28]
Tigresses are smaller than the males in each subspecies, although the size difference between male and female tigers tends to be more pronounced in the larger subspecies of tiger, with males weighing up to 1.7 times more than the females.[29] In addition, male tigers have wider forepaw pads than females. Biologists use this difference to determine gender based on tiger tracks.[30] The skull of the tiger is very similar to that of the lion, though the frontal region is usually not as depressed or flattened, with a slightly longer postorbital region. The skull of a lion has broader nasal openings. However, due to the amount of skull variation in the two species, usually, only the structure of the lower jaw can be used as a reliable indicator of species.[31]
Tigers have round pupils and yellow irises (except for the blue eyes of white tigers). Due to a retinal adaptation that reflects light back to the retina, the night vision of tigers is six times better than that of humansvolution is important to you know:
Physical characteristics, taxonomy and evolution
Tigers first reached India and northern Asia in the late Pleistocene, reaching eastern Beringia (but not the American Continent), Japan, and Sakhalin. Fossils found in Japan indicate that the local tigers were, like the surviving island subspecies, smaller than the mainland forms. This may be due to the phenomenon in which body size is related to environmental space (see insular dwarfism), or perhaps the availability of prey. Until the Holocene, tigers also lived in Borneo, as well as on the island of Palawan in the Philippines.[21]
Physical characteristics
The pattern of stripes is unique to each animal, these unique markings can be used by researchers to identify individuals (both in the wild and captivity), much in the same way that fingerprints are used to identify humans. It seems likely that the function of stripes is camouflage, serving to help tigers conceal themselves amongst the dappled shadows and long grass of their environment as they stalk their prey. The stripe pattern is also found on the skin of the tiger. If a tiger were to be shaved, its distinctive camouflage pattern would be preserved.
Like other big cats, tigers have a white spot on the backs of their ears. These spots, called ocelli, serve a social function, by communicating the animal's mental state to conspecifics in the gloom of dense forest or in tall grass.
The tiger are the most variable in size of all big cats, even more so than the leopard and much more so than lions.[23] Large male Siberian Tigers (Panthera tigris altaica) can reach a total length of more than 3.5 m (11.6 ft) "over curves" (3.3 m or 10.9 ft "between pegs") and a weight of 306 kilograms (675 lbs).[24] This is considerably larger than the sizes reached by island-dwelling tigers such as the Sumatran, the smallest living subspecies, with a body weight of only 75–140 kg (165–310 lbs).[24] Depending upon subspecies tigers may be 1.4–2.8 m (4.6–9.2 ft) long from the nose to the base of the tail, while the tail may add a further 0.6–1.1 m (2–3.6 ft).[25][26] At the shoulder, tigers may variously stand 0.7 to 1.22 m (2.3 to 4.0 ft) tall.[27][28]
Tigresses are smaller than the males in each subspecies, although the size difference between male and female tigers tends to be more pronounced in the larger subspecies of tiger, with males weighing up to 1.7 times more than the females.[29] In addition, male tigers have wider forepaw pads than females. Biologists use this difference to determine gender based on tiger tracks.[30] The skull of the tiger is very similar to that of the lion, though the frontal region is usually not as depressed or flattened, with a slightly longer postorbital region. The skull of a lion has broader nasal openings. However, due to the amount of skull variation in the two species, usually, only the structure of the lower jaw can be used as a reliable indicator of species.[31]
Tigers have round pupils and yellow irises (except for the blue eyes of white tigers). Due to a retinal adaptation that reflects light back to the retina, the night vision of tigers is six times better than that of humansvolution is important to you know:
Tigers 2
now how about knowing their habitats after knowing their names:
During the 19th century, the tiger completely vanished from western Asia and became restricted to isolated pockets in the remaining parts of their range. Today, their range is fragmented, and certain parts degraded, and extends from India in the west to China and Southeast Asia in the east.[19] The northern limit is close to the Amur River in south eastern Siberia. The only large island inhabited by tigers today is Sumatra. Tigers vanished from Java and Bali during the 20th century. In Borneo they are known only from fossil remains.
Tiger habitats will usually include sufficient cover, proximity to water, and an abundance of prey. Bengal tigers live in many types of forests, including wet; evergreen; the semi-evergreen of Assam and eastern Bengal; the mangrove forest of the Ganges Delta; the deciduous forest of Nepal, and the thorn forests of the Western Ghats. Compared to the lion, the tiger prefers denser vegetation, for which its camouflage colouring is ideally suited, and where a single predator is not at a disadvantage compared with the multiple felines in a pride.
Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers. During the extreme heat of the day, they often cool off in pools. Tigers are excellent swimmers, and are able to carry prey through the water.
Range and habitat
In the past, tigers were found throughout Asia, from the Caucasus and the Caspian Sea to Siberia and Indonesia and even in Borneo[16] and Palawan in the Philippines.[17] Today the range of the tiger is only 7% of what it used to be.[18] Furthermore, within the past decade alone, the estimated area known to be occupied by tigers has declined by 41%.[18]During the 19th century, the tiger completely vanished from western Asia and became restricted to isolated pockets in the remaining parts of their range. Today, their range is fragmented, and certain parts degraded, and extends from India in the west to China and Southeast Asia in the east.[19] The northern limit is close to the Amur River in south eastern Siberia. The only large island inhabited by tigers today is Sumatra. Tigers vanished from Java and Bali during the 20th century. In Borneo they are known only from fossil remains.
Tiger habitats will usually include sufficient cover, proximity to water, and an abundance of prey. Bengal tigers live in many types of forests, including wet; evergreen; the semi-evergreen of Assam and eastern Bengal; the mangrove forest of the Ganges Delta; the deciduous forest of Nepal, and the thorn forests of the Western Ghats. Compared to the lion, the tiger prefers denser vegetation, for which its camouflage colouring is ideally suited, and where a single predator is not at a disadvantage compared with the multiple felines in a pride.
Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers. During the extreme heat of the day, they often cool off in pools. Tigers are excellent swimmers, and are able to carry prey through the water.
Tigers
how tigers got their names:
Tigers rarely form groups (see below), but the collective nouns applied when they do are either "ambush" or "streak"
Naming and etymology
The word "tiger" is taken from the Greek word "tigris", which is possibly derived from a Persian source meaning "arrow", a reference to the animal's speed and also the origin for the name of the Tigris river.[10][11] In American English, "tigress" was first recorded in 1611. It was one of the many species originally described by Linnaeus in his 18th century work, Systema Naturae: he called it Felis tigris.[3][12] The generic component of its scientific designation, Panthera tigris, is often presumed to derive from Greek pan- ("all") and theron ("beast"), but this may be a folk etymology. Although it came into English through the classical languages, panthera is probably of Indian origin, meaning "the yellowish animal", or "whitish-yellow".[13]Tigers rarely form groups (see below), but the collective nouns applied when they do are either "ambush" or "streak"
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