The tiger (Panthera tigris) is the largest cat species, reaching
a total body length of up to 3.3 metres (11 ft) and weighing up to 306 kg (670
lb). Their most recognizable feature is a pattern of dark vertical stripes on
reddish-orange fur with lighter underparts. They have exceptionally stout teeth,
and their canines are the longest among living felids with a crown height of as
much as 74.5 mm (2.93 in) or even 90 mm (3.5 in). In zoos, tigers have lived for
20 to 26 years, which also seems to be their longevity in the wild. They are
territorial and generally solitary but social animals, often requiring large
contiguous areas of habitat that support their prey requirements. This, coupled
with the fact that they are indigenous to some of the more densely populated
places on earth, has caused significant conflicts with humans.
Tigers once ranged widely across Asia, from Turkey in the west
to the eastern coast of Russia. Over the past 100 years, they have lost 93% of
their historic range, and have been extirpated from southwest and central Asia,
from the islands of Java and Bali, and from large areas of Southeast and Eastern
Asia. Today, they range from the Siberian taiga to open grasslands and tropical
mangrove swamps. The remaining six tiger subspecies have been classified as
endangered by IUCN. The global population in the wild is estimated to number
between 3,062 to 3,948 individuals, with most remaining populations occurring in
small pockets that are isolated from each other. Major reasons for population
decline include habitat destruction, habitat fragmentation and poaching. The
extent of area occupied by tigers is estimated at less than 1,184,911 km2
(457,497 sq mi), a 41% decline from the area estimated in the mid-1990s.
Tigers are among the most recognisable 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, coats of arms, and as mascots for
sporting teams. The Bengal tiger is the national animal of Bangladesh and India.
Taxonomy and etymology
In 1758, Linnaeus first described the species in his work Systema Naturae under the scientific name Felis tigris.[3] In 1929, the British taxonomist Reginald Innes Pocock subordinated the species under the genus Panthera using the scientific name Panthera tigris.
The word Panthera is probably of Oriental origin and retraceable to the Ancient Greek word panther, the Latin word panthera, the Old French word pantere, most likely meaning "the yellowish animal", or from pandarah meaning whitish-yellow. The derivation from Greek pan- ("all") and ther ("beast") may be folk etymology that led to many curious fables.
The word "tiger" is retraceable to the Latin word tigris meaning a spotted tigerhound of Actaeon. The Greek word tigris is possibly derived from a Persian source.
In 1758, Linnaeus first described the species in his work Systema Naturae under the scientific name Felis tigris.[3] In 1929, the British taxonomist Reginald Innes Pocock subordinated the species under the genus Panthera using the scientific name Panthera tigris.
The word Panthera is probably of Oriental origin and retraceable to the Ancient Greek word panther, the Latin word panthera, the Old French word pantere, most likely meaning "the yellowish animal", or from pandarah meaning whitish-yellow. The derivation from Greek pan- ("all") and ther ("beast") may be folk etymology that led to many curious fables.
The word "tiger" is retraceable to the Latin word tigris meaning a spotted tigerhound of Actaeon. The Greek word tigris is possibly derived from a Persian source.
Characteristics and evolution
The 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.
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.
The 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.
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.
Characteristics
Tigers are muscular, have powerful forequarters, and especially in males, a large head. The ground coloration of their fur varies between tawny and xanthine orange or cinnamon brown in the southernmost populations, to between ochraceous-orange or zinc orange or capucine orange in the northernmost populations. The face is framed by long hairs that form whiskers, which are more conspicuous in males. The ventral parts are usually white. The body is marked with black or chaetura black stripes of various length, breadth and form. The pupils are circular with yellow irises. The rather small ears are rounded and black on their dorsal side with a conspicuous white central spot. These spots, called ocelli, play an important role in intraspecific communication.
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.
The tiger are the most variable in size of all big cats, even
more so than the leopard and much more so than lions.[16] The Bengal, Caspian
and Siberian tiger subspecies represent the largest living felids, and rank
among the biggest felids that ever existed. Females vary in size from 240 to 275
cm (94 to 108 in), weigh 85 to 167 kg (190 to 370 lb) with a greatest length of
skull ranging from 268 to 318 mm (10.6 to 12.5 in). Males vary in size from 270
to 330 cm (110 to 130 in), weigh 170 to 306 kg (370 to 670 lb) with a greatest
length of skull ranging from 316 to 383 mm (12.4 to 15.1 in). Body size of
different populations seems to be correlated with climate—Bergmann's Rule—and
can be explained from the point of view of thermoregulation.[4] Large male
Siberian tigers can reach a total length of more than 3.5 m (11 ft) "over
curves", 3.3 m (11 ft) "between pegs" and a weight of 306 kg (670 lb). This is
considerably larger than the size reached by the smallest living tiger
subspecies, the Sumatran tiger, which reach a body weight of 75 to 140 kg (170
to 310 lb). At the shoulder, tigers may variously stand 0.7 to 1.22 m (2.3 to
4.0 ft) tall.
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 tiger subspecies, with males weighing up to 1.7 times
more than the females. In addition, male tigers have wider forepaw pads than
females. Biologists use this difference to determine gender based on tiger
tracks.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.
Biology and behaviour
Adult tigers lead solitary lives and congregate only on an ad hoc and transitory basis when special conditions permit, such as plentiful supply of food. They establish and maintain home ranges. Resident adults of either sex tend to confine their movements to a definite area of habitat, within which they satisfy their needs, and in the case of tigresses, those of their growing cubs. Those sharing the same ground are well aware of each other's movements and activities.
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 km2 (7.7 sq mi), while the territories of males are much larger, covering 60 to 100 km2 (23 to 39 sq mi). The range of a male tends to overlap those of several females.[citation needed]
Tigers are strong swimmers, and are often found bathing in ponds, lakes, and rivers. During the extreme heat of the day, they often cool off in pools. They are able to carry prey through the water.
Tigers for the most part are solitary animals.
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. 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 National Park:
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.
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 mark 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.
Two male Bengal tiger siblings play with each other in the Pilibhit Tiger Reserve, India.
Tiger dentition (above), compared with that of an Asian black bear (below). The large canines are used to make the killing bite, but they tear meat when feeding using the carnassial teeth.
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. 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. 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 a rare occurrence.
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. Like the other Panthera cats, tigers can roar. Tigers will roar for both aggressive and non-aggressive reasons. Other tiger vocal communications include moans, hisses, growls and chuffs.
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 criticized as being inaccurate. 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.
Adult tigers lead solitary lives and congregate only on an ad hoc and transitory basis when special conditions permit, such as plentiful supply of food. They establish and maintain home ranges. Resident adults of either sex tend to confine their movements to a definite area of habitat, within which they satisfy their needs, and in the case of tigresses, those of their growing cubs. Those sharing the same ground are well aware of each other's movements and activities.
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 km2 (7.7 sq mi), while the territories of males are much larger, covering 60 to 100 km2 (23 to 39 sq mi). The range of a male tends to overlap those of several females.[citation needed]
Tigers are strong swimmers, and are often found bathing in ponds, lakes, and rivers. During the extreme heat of the day, they often cool off in pools. They are able to carry prey through the water.
Tigers for the most part are solitary animals.
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. 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 National Park:
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.
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 mark 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.
Two male Bengal tiger siblings play with each other in the Pilibhit Tiger Reserve, India.
Tiger dentition (above), compared with that of an Asian black bear (below). The large canines are used to make the killing bite, but they tear meat when feeding using the carnassial teeth.
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. 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. 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 a rare occurrence.
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. Like the other Panthera cats, tigers can roar. Tigers will roar for both aggressive and non-aggressive reasons. Other tiger vocal communications include moans, hisses, growls and chuffs.
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 criticized as being inaccurate. 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.
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