Tigers are the largest members of the cat family and are renowned for their power and strength. There were eight tiger subspecies at one time, but three became extinct during the 20th century. Over the last 100 years, hunting and forest destruction have reduced tiger populations from hundreds of thousands of animals to perhaps fewer than 2,500. Tigers are hunted as trophies, and also for body parts that are used in traditional Chinese medicine. All five remaining tiger subspecies are endangered.
There are 6 subspecies of the tiger alive today. They are the, Amur (Siberian) Tiger, Bengal (Indian) Tiger, Indochinese Tiger, Malayan Tiger, South China Tiger and the Sumatran Tiger. They are mainly distinguished by their size, coat and colour. However differences are usually very subtle, and it can be hard to tell apart different subspecies.
The average size of a tiger depends on its subspecies and gender. Body length (including the tail) approximately equals 140-300 cm, and the tail length is around 60-95 cm.
Males of the Siberian tiger, the largest subspecies, can weigh up to 300 kg, in contrast to the males of the smallest subspecies, the Sumatran tiger, where the range is 100-140 kg. Typically in every subspecies the males are heavier than the females.
The tiger has an excellent skeleton which is perfectly suited to its hunting habits and daily behaviours. It enables it to endure both the contrasting rigors of speed and strength.
Tigers have longer hind legs than forelegs and can therefore spring forward 10 meters (32.5 feet), while the reduced size of their clavicle (collarbone) allows greater stride length. Their solid forelimb bones can support large muscles and give their forelegs great power, enabling them to bring down large prey.
In addition the bones of a tiger's feet are closely bound by ligaments to make them strong enough to survive the impact of landing, an important factor in the tiger's ability to sprint at high speeds.
Tigers tend to have light yellow-orange to deep reddish-orange background coloration. There are also reports of melanistic (black) coloured tigers, but confirmation is still required to check whether they are truly melanistic or merely darker versions of the orange tigers. White coloured tigers also exist, although they are not considered albinos. Albinos would be pure white in colour without stripes, and would have pink or red eyes. White tigers are leucocystic - meaning they have a recessive gene that causes them to lack dark colours. They usually have light to medium brown striping, and blue eyes. It is unknown why, but white tigers appear to grow bigger at a faster rate compared to their orange counterparts.
The fur provides warmth, protection and camouflage. There are two different types of hair/fur, the guard hair and the underfur. The guard hairs are more durable and long and mainly act as protection. The primary aim of the tiger’s hair is for warmth. The underfur therefore traps air which then insulates the tiger’s body, keeping it warm.
The fur of a tiger is immediately made obvious by its black stripes. They are the only feline member who possesses the characteristic stripes. There are also different types of striping found on the tiger, whether it be on their stomach, face, sides or legs. They are single loop, and double loop striping. The stripes vary in width and length and colours from light brown to black.
Tigers have thirty teeth, fewer than other carnivores (dogs and bears have forty two) but no less dangerous, because of their specialization.
The tiger has the largest canines of all the big cats, at 6.4 to 7.6 centimetres (2.5 to 3 inches) long. They are rich in pressure-sensitive nerves, enabling the tiger to make an accurate stab between a victim's neck bones to severe the spinal cord. The back teeth, carnassials, act as shearing blades, with which tigers are able to slice the meat off their prey. The incisors (small front teeth) are positioned in a straight line, enabling them to efficiently pluck feathers and clean meat off the bone. The huge gap between the canines and carnassials, means the tiger can dig its teeth deep into its prey for the kill.
Tigers live in environments that can sometimes be rather harsh and are completely independent. This means that their very survival depends on their own efforts, skills and sensory perception; with no assistance from a pack. They are accomplished hunters, and their bodies are designed and built for the kill. Their senses are crucial to their success and, indeed, life. Like most mammals, tigers have five main senses:
Sound - Auditory Communication
Tigers have exceptional hearing, which they use to locate prey in dense cover. Their hearing is probably similar to the hearing of domestic cats. Domestic cats can hear sounds in the range of about .2 kHz to 65 kHz.
As avid hunters, tigers need to have acute hearing so that they are able to detect potential prey in the bushes and grasses around them.
A tiger's hearing is its most highly developed sense, far more important to its success as a hunter than either sight or smell. With large pinnae - external ear flaps - rotating like radar dishes, a tiger can catch many sounds and with experience determine precisely where they originated. The ear picks up the high-frequency sounds made by prey rustling in the undergrowth and also low-frequency contact calls, neither of which humans can hear.
The tiger's ability to communicate by infrasound, a sound wave with a frequency below the range of normally audible sound (twenty hertz), has opened a new and exciting area of research. Many animals, such as elephant and whales, communicate at this low-pitched level. Infrasound is fantastically useful for communicating over long distances or through dense vegetation because it literally passes straight through objects ranging from leaves to trees to mountains. It is the perfect tool with which a solitary animal like the tiger can communicate with rivals and mates who are distributed widely in dense jungle.
They are also verbal communicators as well. Some people assume that the roar is only something that the lion does but it is also one of the tiger as well. The males may use it to find mates or to warn other males to get out of their territory. Due to the amazing sense of hearing they have, it is believed that these roars can be heard up to 2 miles in distance. This means they can draw other tigers that live in the area but that aren’t in their immediate territory.
Moaning is another type of communication that tigers use. This is believed to be a type of gentle coaxing. The mothers are often going to use it to get their young to follow their directions and to try new things. Males may use moaning during the courting process to help the females feel more relaxed. This helps them to feel woed instead of threatened.
They will often be heard snarling when they feel they are in danger. A mother is very likely to use this form of communication to keep other animals and even tiger males away from her offspring. Snarling and hissing are common too when other tigers are attempting to cash in on a meal that another has claimed as their own.
Sight - Visual Communication
The eyesight of the tiger is exceptionally good, particularly at night. The eye has been designed to see very well in the dark. In normal daylight, the tiger sees about as well as we do, but without the detail that we can enjoy. At night, though, their vision is about six times better than that of a human being. They can also judge distances, which is essential to their success in hunting, since they need to pounce on unsuspecting prey with accuracy and agility.
The upper and lower eyelids of cats, like those of humans, sheathe the eyeballs. For further protection, all cats have an opaque, white third eyelid, called the nictitating membrane, between the lower lid and inside corner of the eye. This layer helps moisten the eye and clear dust from the surface of the cornea. Many other animals, including dogs, horses, and birds, also have a nictitating membrane.
Smell - Olfactory Communication
Tigers use this helpful sense when they are interacting with other tigers, and not so much in hunting. Tigers use personal scents to mark their territory. Other tigers will be eager to smell the scent of their peers. Females use their scents to mark specific territories to let males know that they are ready to mate.
When smelling another tiger's scent mark, a tiger will wrinkle its nose and hang out its tongue in a grimace called flehmen. Flehmen is used to draw a scent to the Jacobson's Organ (a sensitive organ in the roof of the mouth), which receives the chemical information.
Touch - Tactile Communication
Tigers use their well-developed sense of touch for several purposes. These include rubbing against one another (as in courting couples or family members) and for mothers to maintain personal contact with their cubs. Sensitive whiskers and padded feet give tigers the ability to feel their way silently - even in pitch darkness, through dense cover - to approach unwary prey.
Tigers have specialized hairs on their heads known as whiskers, or vibrissae, which serve a sensory function. About twice as thick as the outer guard hairs of the coat, they are rooted more deeply in the skin, in a capsule of blood. When the whiskers brushes against something, its root moves the blood, thus simplifying the movement. Nerves pick up on the movement and send signals to the brain.
Whiskers are grouped in four different positions. The most important and well-developed are the mystacial group on the muzzle. Typically these are extended, at right angles to the jaws, when the tiger is resting. When sniffing, tigers retract these whiskers against the side of the face. As they advance, they bring them forward in the direction of the mouth like a circular net. The net of whiskers senses a prey's attempts to escape and provides crucial information about shere to inflict the fatal bite. We now know that the whiskers and eyes function together, complementing each other.
General Tiger Communication
Tigers have a number of ways in which they communicate with each other. If you have a domestic cat then you are already familiar with several of them. For example they may arch their backs and put out the claws when they feel threatened or they are ready to fight. This is a great way to get other tigers and other animals in the area to back away from them so they don’t have to engage in a fight. They would rather warn them instead of engaging in fighting.
They can be seen with their ears back, their heads up high, the paws in place, and the teeth showing. These are all prime indicators that the tiger is ready to pounce on something that it has seen. If they are merely curious though about other animals or tigers in the area they will have their ears up and their tail held up high instead of the normal low laying position. This shows that they are on alert but not feeling threatened at that time.