Anatomy and Physiology

Weight: Tigers are sexual dimorphic, females are on average 275-400 pounds and males are 400 to 600 pounds. However male tigers can get as big as 800 pounds.
The differences in anatomy between tiger subspecies is not genetic, rather it is due to the environment selecting for various characteristics. This is why tiger measurements across sub-species are approximations.

Length: Depending on the gender, the head-body length of a tiger is about 1.4-2.8 m. The length of the tail is 90-120 cm.Shoulder Height: 36-42 inches

Claws: Tiger claws are retractable usually are between 3.5 - 4 inches though.There are five claws (including the dew-claw) on the forefeet, and four claws (no dew claw) on the hind feet.Tigers sharpen their claws by scraping them on tree bark. The scratch marks left on trees also serve as territorial markers against other tigers.

Eyes:Tigers have round pupils and yellow irises (white Bengal tigers have blue irises) (source: 5tigers.org).An adaptive trait that tigers have is called a tapedum (humans don't have this trait but several other species have this; especially nocturnal animals). It reflects light back to the retina and causes a tiger's eyes to 'glow' in the dark and is responsible for their strong night vision which is approx. six times better than humans. Tigers do not have good color vision. They lack a type of cell(cones)that allows them to see color, but in turn have more of another type of cell(rods) which allows them to see better at low light levels.

Fur:The tell-tale orange coat with black stripes covers most of the body. However, the stomach is white. Additionally, white tigers do not have stripes on their stomachs as well.A tiger's black stripes act as camouflage which aides in hunting. The pattern of stripes gives each tiger his/her own distinctive appearance.Tigers fur length is ~7 to 20 mm on the back and ~15 to 35 mm on the stomach.

Tail:Averages around 36 inches in length Like in all other tailed animals, a tiger's tail is utilized in maintaining balance while running, turning, and navigating in high areas. A tiger's tale, along with is face, can help display a tiger's mood.

Teeth:An adult tiger has 30 teethLike other animal, tigers have incisors, canines, premolars, and molars.Depending on the type of tooth, the size can vary from > 1 inch to 3 inches (canine teeth being the longest)

Whiskers: A tiger's whiskers are sensitive and are used as sensory preceptors. A tiger's whiskers average around 15 cm, and are around 3.0 mm thick at the base. Male whiskers are typically longer than female's.

Lifespan: Around 15 years in the wild (up to 25 years in captivity).Sexual maturity: 3-4 years

Number of young: 1 to 5 (usually has 2-3 cubs per pregnancy).Social Life Tigers are solitary animals who usually live on their own. A group of tigers is called a “streak”, which is usually a small group consisting of a mother and her cubs.

Gestation: 95-112 daysBirth: Tiger cubs are initially blind when they are born (like humans and most other animals) and weigh approximately two-three pounds (one kilogram.

Development: For the first six-eight weeks, cubs are dependent on their mother's milk. Eight weeks after birth, cubs will start joining their mother in hunting. At six months, their mother will usually break the legs or injure their prey so the cubs can learn how to kill it.

Adolescence: Tigers have fully developed canines by 16 months of age, but they do not begin making their own kills until about 18 months of age.

Maturation: Cubs are raised by their mother and stay with her for approximately 2 years. During this time, they will learn how to hunt as well as acquire other behavioral traits such as grooming and sharpening their claws.

Adulthood: After 1.5 years, tigers have the ability to sustain themselves.

Bengal Tiger Classification

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Feidae
Genus: Panthera
Species: tigris
Sub-species: tigris

Problem

In the past 100 years, the number of tigers has been reduced by 95%. By the turn of the century alone, 3 sub-species of tigers (Bali, Java, Caspian ) were driven to extinction. Unfortunately, the 5 remaining subspecies seem to be headed to a similar fate. These extremely large numbers of tiger population losses in the world are due to many factors, most of which involve human interferance.
The loss, fragmentation, and degradation of forests have been a great factor to the loss of Bengal Tigers. Habitat loss remains one of the biggest dangers that threaten tiger populations in South and Southeast Asia. In countries like India (where the majority of Bengal Tigers reside) people are always looking to expand their living space, which overlaps with tiger populations. During the 20 years since Project Tiger began in 1973, India's human population has increased by over 300 million and livestock by over 100 million. The people transform the ecological systems with cattle, and crops which in turn harm the tigers by leaving them with little or no space to live, hunt and reproduce successfully. Number s of tiger prey drop, and the tigers are forced to move or even hunt humans and livestock for food, and are later penalized for this with death.
Tiger skins have long been an object of desire, used to adorn houses and buildings as rugs, wall hangings, and even coats for people. Though they are still in demand, now that there are trade bans however, poaching has changed targets, focusing mainly on bones and other body parts to meet the demand for pseudo-medicinal us in China, Taiwan, south Korea and Indo-China. The statistics show that over six tons of tiger bones were imported between 1975 and 1992, which could represent the equivalent of 500 to 1,000 tigers (using dry bone weights of 10-12kg per tiger). Nearly two-thirds of the imports to South Korea were from Indonesia, with China second at 14 per cent (probably re-exports). Other listed suppliers were Japan, Thailand, Malaysia, India, Singapore, and Taiwan.
Another major problem that aids the steadily decreasing number of Bengal tigers, is the failure to enforce laws concerning illegal poaching and trading. Evidence has been collected showing that tiger-based medicine is still widely available despite announced bans and laws. Tigers will therefore remain under serious threats with regards to poachers willing to continue hunting them for their bones and furs.
Because most tiger populations today consist of less than 100 tigers, only of which 40% form the breeding population, reproduction among the tiger populations is also reducing and becoming more difficult. Inbreeding is therefore unavoidable, and many cases of father-daughter as well as mother-son breeding have been recorded. This loss of variability leads to genetic deterioration with lower cub production and survival.
Finally, another problem leading to the deterioration of tiger populations is due to natural disasters such as floods, forest fires, hurricanes, and epidemics. Monsoon floods and hurricanes usually kill several tigers in the Indian subcontinent.