Sonntag, 26. April 2009

Tiger


Tiger
Pictures, Moving and Author by Selzer-McKenzie
The tiger (Panthera tigris) is a member of the Felidae family; the largest of the four "big cats" in the genus Panthera.[4] Native to much of eastern and southern Asia, the tiger is an apex predator and an obligate carnivore. Reaching up to 4 metres (13 ft) in total length and weighing up to 300 kilograms (660 pounds), the larger tiger subspecies are comparable in size to the biggest extinct felids.[5][6] Aside from their great bulk and power, their most recognizable feature is the pattern of dark vertical stripes that overlays near-white to reddish-orange fur, with lighter underparts. The largest subspecies of tiger is the Siberian tiger.

Highly adaptable, tigers range from the Siberian taiga, to open grasslands, to tropical mangrove swamps. They are territorial and generally solitary animals, often requiring large contiguous areas of habitat that support their prey demands. This, coupled with the fact that they are endemic to some of the more densely populated places on earth, has caused significant conflicts with humans. Of the eight subspecies of modern tiger, two are extinct and the remaining six are classified as endangered, some critically so. The primary direct causes are habitat destruction and fragmentation, and hunting. Their historical range, which once reached from Mesopotamia and the Caucasus through most of South and East Asia, has been radically reduced. While all surviving species are under formal protection, poaching, habitat destruction and inbreeding depression continue to be threats.

Nonetheless, tigers are among the most recognizable and popular of the world's charismatic megafauna. They have featured prominently in ancient mythology and folklore, and continue to be depicted in modern films and literature. Tigers appear on many flags and coats of arms, as mascots for sporting teams, and as the national animal of several Asian nations.
Tigers are essentially solitary and territorial animals. The size of a tiger's home range mainly depends on prey abundance, and, in the case of male tigers, on access to females. A tigress may have a territory of 20 square kilometres while the territories of males are much larger, covering 60–100 km2. The ranges of males tend to overlap those of several females.
The relationships between individuals can be quite complex, and it appears that there is no set "rule" that tigers follow with regards to territorial rights and infringing territories. For instance, although for the most part tigers avoid each other, both male and female tigers have been documented sharing kills. For instance, George Schaller observed a male tiger share a kill with two females and four cubs. Females are often reluctant to let males near their cubs, but Schaller saw that these females made no effort to protect or keep their cubs from the male, suggesting that the male might have been the father of the cubs. In contrast to male lions, male tigers will allow the females and cubs to feed on the kill first. Furthermore, tigers seem to behave relatively amicably when sharing kills, in contrast to lions, which tend to squabble and fight. Unrelated tigers have also been observed feeding on prey together. The following quotation is from Stephen Mills' book Tiger, as he describes an event witnessed by Valmik Thapar and Fateh Singh Rathore in Ranthambhore:[50]

A dominant tigress they called Padmini killed a 250 kg (550-lb) male nilgai - a very large antelope. They found her at the kill just after dawn with her three 14-month-old cubs and they watched uninterrupted for the next ten hours. During this period the family was joined by two adult females and one adult male - all offspring from Padmini's previous litters and by two unrelated tigers, one female the other unidentified. By three o'clock there were no fewer than nine tigers round the kill.

A tiger is capable of jumping to almost twice its height

When young female tigers first establish a territory, they tend to do so fairly close to their mother's area. The overlap between the female and her mother's territory tends to wane with increasing time. Males, however, wander further than their female counterparts, and set out at a younger age to eke out their own area. A young male will acquire territory either by seeking out a range devoid of other male tigers, or by living as a transient in another male's territory, until he is old and strong enough to challenge the resident male. The highest mortality rate (30-35% per year) amongst adult tigers occurs for young male tigers who have just left their natal area, seeking out territories of their own.[51]

Male tigers are generally more intolerant of other males within their territory than females are of other females. For the most part, however, territorial disputes are usually solved by displays of intimidation, rather than outright aggression. Several such incidents have been observed, in which the subordinate tiger yielded defeat by rolling onto its back, showing its belly in a submissive posture.[52] Once dominance has been established, a male may actually tolerate a subordinate within his range, as long as they do not live in too close quarters.[51] The most violent disputes tend to occur between two males when a female is in oestrus, and may result in the death of one of the males, although this is actually a relatively rare occurrence.[51][53]

To identify his territory, the male marks trees by spraying of urine and anal gland secretions, as well as marking trails with scat. Males show a grimacing face, called the Flehmen response, when identifying a female's reproductive condition by sniffing their urine markings.

Tigers have been studied in the wild using a variety of techniques. The populations of tigers were estimated in the past using plaster casts of their pugmarks. This method was found faulty[54] and attempts were made to use camera trapping instead. Newer techniques based on DNA from their scat are also being evaluated. Radio collaring has also been a popular approach to tracking them for study in the wild.
India harbors the largest population of wild tigers in the world, along with one of the highest human populations. A major concerted conservation effort known as Project Tiger has been underway since 1973, spearheaded by Indira Gandhi. The fundamental accomplishment has been the establishment of over 25 well-monitored tiger reserves in reclaimed land where human development is categorically forbidden. The program has been credited with tripling the number of wild Bengal tigers from roughly 1,200 in 1973 to over 3,500 in the 1990s, though the reports of the Indian government are occasionally met with some skepticism.[citation needed] A recently passed tribal Bill, which allows tribal populations to reside inside designated tiger sanctuaries, may have impacts on the continuing success of the program.[citation needed]

A tiger census carried out over 2007, whose report was published on February 12, 2008 stated that the wild tiger population in India has come down to approximately 1,411. It is noted in the report that the decrease of tiger population can be attributed directly to poaching.
n the historical past tigers were widespread in Asia, from the Caucasus and the Caspian Sea, to Siberia and Indonesia. During the 19th century the striped cats completely vanished from western Asia, and became restricted to isolated pockets in the remaining parts of their range. Today, this fragmented relic range extends from India in the west to China and Southeast Asia in the east. 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, and in Borneo are known only from fossil remains.

Keine Kommentare:

Kommentar veröffentlichen

Hinweis: Nur ein Mitglied dieses Blogs kann Kommentare posten.