tigers - biology & behavoir
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.
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.
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 actually
a relatively 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.
hunting & diet
In the wild, tigers mostly feed on larger and medium sized animals. Sambar, gaur, domestic buffalo, chital, boar, and nilgai are the
tiger's favored prey in India. Sometimes, they also prey on leopards, pythons, sloth bears and crocodiles. In Siberia the main prey species
are Mandchurian elk, wild boar, Sika Deer, Moose, roe deer, and musk deer. In Sumatra Sambar, Muntjac, wild boar, and Malayan Tapir are
preyed on. In the former Caspian tiger's range, prey included Saiga Antelope, camels, Caucasian Wisent, yak, and wild horses. Like many
predators, they are opportunistic and will eat much smaller prey, such as monkeys, peafowls, hares, and fish.
Adult elephants are too large to serve as common prey, but conflicts between tigers and elephants do sometimes take place. A case where a
tiger killed an adult Indian Rhinoceros has been observed. Young elephant and rhino calves are occasionally taken. Tigers also sometimes
prey on domestic animals such as dogs, cows, horses, and donkeys. These individuals are termed cattle-lifters or cattle-killers in contrast
to typical game-killers.
Old tigers, or those wounded and rendered incapable of catching their natural prey, have turned into man-eaters; this pattern has recurred
frequently across India. An exceptional case is that of the Sundarbans, where healthy tigers prey upon fishermen and villagers in search of
forest produce, humans thereby forming a minor part of the tiger's diet. Tigers will occasionally eat vegetation for dietary fiber, the fruit
of the Slow Match Tree being favoured.
Tigers usually hunt at night. They generally hunt alone and ambush their prey as most other cats do, overpowering them from any angle,
using their body size and strength to knock large prey off balance. Even with their great masses, tigers can reach speeds of about 49
- 65 kilometres per hour (35 - 40 miles per hour), although they can only do so in short bursts, since they have relatively little stamina;
consequently, tigers must be relatively close to their prey before they break their cover. Tigers have great leaping ability; horizontal
leaps of up to 10 metres have been reported, although leaps of around half this amount are more typical. However, only one in twenty hunts
ends in a successful kill.
When hunting large prey, tigers prefer to bite the throat and use their forelimbs to hold onto the prey, bringing it to the ground. The
tiger remains latched onto the neck until its prey dies of strangulation. By this method, gaurs and water buffalos weighing over a ton
have been killed by tigers weighing about a sixth as much. With small prey, the tiger bites the nape, often breaking the spinal cord,
piercing the windpipe, or severing the jugular vein or common carotid artery. Though rarely observed, some tigers have been recorded to
kill prey by swiping with their paws, which are powerful enough to smash the skulls of domestic cattle, and break the backs of sloth bears.
During the 1980s, a tiger named "Genghis" in Ranthambhore National Park was observed frequently hunting prey through deep lake water,
a pattern of behaviour that had not been previously witnessed in over 200 years of observations. Moreover, he appeared to be extraordinarily
successful for a tiger, with as many as 20% of hunts ending in a kill.
reproduction
Mating can occur all year round, but is generally more common between November and April. A female is only receptive for a few days
and mating is frequent during that time period. A pair will copulate frequently and noisily, like other cats. The gestation period is 16
weeks. The litter size usually consists of around 3 - 4 cubs of about 1 kg (2 lb) each, which are born blind and helpless. The females
rear them alone, sheltering them in dens such as thickets and rocky crevices. The father of the cubs generally takes no part in rearing
them. Unrelated wandering male tigers may even kill cubs to make the female receptive, since the tigress may give birth to another litter
within 5 months if the cubs of the previous litter are lost. The mortality rate of tiger cubs is fairly high - approximately half do not
survive to be more than two years old.
There is generally a dominant cub in each litter, which tends to be male but may be of either sex. This cub generally dominates its
siblings during play and tends to be more active, leaving its mother earlier than usual. At 8 weeks, the cubs are ready to follow their
mother out of the den, although they don't travel with her as she roams her territory until they are older. The cubs become independent
around 18 months of age, but it is not until they are around 2 - 2 1/2 years old that they leave their mother. Females reach sexual maturity
at 3 - 4 years, whereas males reach sexual maturity at 4 - 5 years.
Over the course of her life, a female tiger will give birth to an approximately equal number of male and female cubs. Tigers breed well in
captivity, and the captive population in the United States may rival the wild population of the world.
« back