Legs and Feet
Tigers are built for strength, not sustained speed. In short bursts they can achieve speed of above 35 miles per hour.The hind legs of the tiger are longer than their front legs. Their powerful legs enable them to leap forward distances up to 10 meters (32.5 ft). A tiger was captured on video jumping—flying—from flat ground to 13 feet in the air to attack a ranger riding an elephant. The bones of the tiger’s front legs are strong and dense to support the large musculature needed to take down large prey. The bones in each of the tiger’s feet are tightly connected by ligaments enabling them to buffer the impact of landing from running, pouncing and leaping. Tigers have large padded feet that enable them to silently stalk prey in the Asian jungles.
The claws of the tiger are up to 10 centimetres (4 in) in length and are used to grasp and hold onto prey. Each paw has four of these claws and one specialized claw called a dewclaw. A dewclaw is located farther back on the foot and thereby does not touch the ground when walking. Dewclaws function similarly to thumbs in that they are used for grasping prey and aid in climbing. Curved claws enable the cat to superiorly grasp and hold large prey and climb trees head-first. However, the curvature of claws, size and weight of the animal is great hindrance in climbing down from trees. Therefore, tigers either crawl backwards or jump down from trees, making them the most inferior climbers of the big cat family.
Tiger claws are retractable. Ligaments hold them in a protective skin sheath when they are not being used. The ligaments are in a relaxed position when the claws are retracted thereby expending no musculature effort. Tigers retract their claws to ensure that they remain sharp for times when they are needed and to tread silently up to unsuspecting prey. Other ligaments will extract the claws when attacking prey or defending themselves which does require musculature effort.
Tigers on trees!!!
It’s a popular belief that tigers can’t climb trees, but it is not entirely true. There have been occasions where these cats have been found sitting on trees. In his book “Wild Animals in Central India” (1923), A.A. Dunbar Brander has stated, “Tigers seldom attempt to climb trees but they can do this to a much greater extent than is generally supposed. I firmly believe they can certainly get up a branched tree at which they can rush. The number of fatal accidents is evidence of this. I do not think a large heavy tiger could climb a smooth limbless tree, but tigresses and smaller tigers can get up a tree with only a small amount of assistance from side branches.”
Valmik Thapar wrote in his “Tiger: Portrait of a Predator” (1986), “Once, while we were watching Laxmi (a tigress) and her three cubs. One of the youngsters suddenly walked up to a tree, climbed a metre or two up the trunk, and went and sat on the first overhanging branch. Above him sat a peacock, which he watched curiously as the peacock called in alarm.
Mobility among these predators is an ever-changing phenomenon that depends on numerous factors most importantly change of season, availability of water and the movement of the prey. These cats seem to more mobile in winters rather than the summers. This is perhaps due to the lower temperature and sufficient water which disperses the prey species around the numerous water holes.
Head, Collarbone & Dentition
The skull of the tiger is stout and rounded in shape which provides more support for their powerful jaws. Jaw muscles are attached to a bony ridge that lay on top of the skull called the sagittal crest. These muscles function to rapidly clamp down on prey with crushing force. These cats have a reduced-sized clavicle (collarbone), which enables them to attain greater stride lengths. The smaller clavicle allows for a wider, unrestricted range of movement of the scapula (shoulder blade) when running.
Tigers have fewer teeth than other carnivores such as dogs (42 teeth) with only 30 teeth. All cats have deciduous (temporary) teeth that come in within a week or two after birth and are referred to as milk teeth similar to humans’ baby teeth. The milk teeth are eventually replaced by the permanent ones. Therefore they are seldom without a set of teeth. Tigers have the largest canines of all big cat species ranging in size from 6.4 to 7.6 centimetres (2.5 to 3.0 in) in length. The canines have abundant pressure-sensing nerves that enable the tiger to identify the location needed to sever the neck of its prey. Back teeth of tigers are called carnassials which enable them to shear meat from their prey like knife blades. They swallow large-sheared pieces of meat whole. These big cats are capable of penetrating deeply into their prey because of the large gap between the carnassials (back teeth) and the canines hold prey tightly. The small incisors located in the front of the mouth (between the two top and bottom canines) facilitate the predator to pick off meat and feathers from their prey. Tiger’s tongue is covered with numerous small, sharp, rear-facing projections called papillae which give the tongue rough, rasping texture and is designed to help strip feathers, fur and meat from prey, especially from bones.
Tiger stalks the prey and tries to reach as close as possible before making the final charge. While chasing they use their tail for balance when making sharp turns in pursuit of prey. Their striped coat comes handy which blends beautifully with the surroundings and gives the cat a completely camouflaged cover. Its assault is designed to throw the prey off its feet – no easy job when the animal is as big as a gaur that weighs about a ton and is the largest of wild cattle and also about five times the tiger’s weight. Depending on the size of the prey tiger’s killing bite is usually to the throat or on the neck of the victim. While dealing with the large prey, like water buffalo or a gaur, tiger inflicts throat bite as it goes down, pinning the hapless victim to the ground and bracing itself on its elbows, chest close to the ground and hindquarters raised. Victim dies by suffocation. If during the initial assault tiger’s teeth wind up in the back of the neck, the grip is immediately shifted to the throat once the prey falls. The cat is so powerful that even the herculean efforts of the victim to right itself is usually in vain. In case of smaller animals, like deer, bite on the nape is often sufficient to sever the spinal cord.
The reason for the different tactics seems to be that the nape of a large animal is protected by heavy slabs of muscles and a considerable amount of bone, making it difficult for the cat to deliver a lethal bite. By grabbing the throat, however, the cat can strangle its victim. The process is rarely quick – the fallen animal may take some minutes to die. It is not usual for tigers to feed together at a kill. If ever it happens it is either because they are a mating pair or a mother and offspring. On rare occasions male tigers also may permit a female with young to feed at their kill.
Because tigers like to soak in water during the heat of the day and frequently drink while eating, they often haul their prey to the banks of the nearest pool or stream, as long as there is enough brush to provide cover. They usually begin eating at the animal’s rump. As far as carrying of the carcass is concerned cattle and buffalo that could not be moved by fewer than ten or twelve men have been dragged hundreds of feet by a tiger, which may even leap for several yards while holding the carcass. Generally tigers drag their prey by the neck, but they have been seen carrying the victim over the shoulder. Tigers can consume 20 to 35 kg (44-77 lb.) of food at one sitting; but they usually eat about 15 to 18 kg (33-40 lb.) of food a day, over several days. If their food requirements are averaged per day over a year, females need about 5 to 6 kg (11-13 lb.) of food per day whereas males need about 6 to 7 kg (13-15 lb.) of food per day. It is estimated that every tiger consumes about 50 deer-sized animals each year, about one per week.
Researchers in Nepal have found that female tigers without young killed every 8 to 8.5 days (42-45 kills per year). Similar kinds of findings have also come out from India. Female tigers with two cubs ages six to ten months old killed every five to six days (61-73 kills per year).
Since big cats do not eat every day, the total amount of food required over a prolonged period is consumed in periodic gorging, usually spaced a few days apart. A cat does not have to kill a new animal every time it needs to eat. Most of the big cats can make several meals out of a single large victim. If there is anything left of a tiger’s prey, the cat heap leaves, grass, and earth over it. Grass may be bitten off in swatches and deposited. Or else the cat turns its back towards the carcass and sweeps earth and debris over it with a front paw. Tigers go so far as to shove carcass between boulders to conceal them.
Like leopards, striped cats are also notorious for feeding even on flesh that is badly decomposed. Sometimes a tiger will dig up the bodies of domestic animals that have been buried by their owners. There is one recorded case of a tiger digging up a cow carcass that had been dropped in a hole five feet deep and covered with a four-inch layer of dirt topped by heaps of thorn-studded branches.
Big cats sometimes travel great distances in search of food, especially when the prey is scarce. Tigers often patrol their neighbourhood all night long, travelling more than a dozen miles while their keen eyes survey the darkness for prey. The progress of the big cat on the prowl is often announced by alarm calls from the little barking deer that also share the range with the cat. Tigers also turn to water when there is scarcity of prey. Striped cats inhabiting mangrove swamps of Sunderbans on India-Bangladesh border regularly hunt fish on tidal creeks. Throughout their range, tigers catch and kill creatures ranging from bears and badgers to lizards and porcupines.
The process of converting meat to protein (needed for energy) is significantly less complicated in carnivores than it is to convert grass to protein as some herbivores require. Carnivores do not require the vast amount of microbes (microscopic bacteria) living in their intestines to break down indigestible plant cellulose. Therefore tigers and other carnivores have small and light weight stomachs that do not hinder them when they are accelerating quickly to chase prey.
In addition to the upper and lower eyelids that protect the eye, cats and other animals such as crocodilians (alligators, crocodiles, etc.) have a nictitating membrane on each eye that helps keep it moist and removes dust from the surface.
Tigers have forward facing eyes rather than one on each side of their head. This provides binocular vision because each eye’s field of vision overlaps creating a three dimensional image. Binocular vision enables them to accurately assess distances and depth which is extremely useful for manoeuvring within their complex environment and stalking prey. Their eyes have more rods (responsible for visual acuity for shapes) than cones (responsible for colour vision) to assist with their night vision. The increased number of rods allows them to detect movement of prey in darkness where colour vision would not be useful. Research suggests that cats in general are capable of seeing the colours green, blue and possibly red, just in less saturation or strength than we see.
Tiger eyes have a structure at the back, behind the retina, called the tapetum lucidum, which enables them to have better night vision. This mirror-like structure reflects light (that has not already been absorbed by the eye) back into the eye a second time to help produce a brighter image. The tapetum lucidum causes their eyes to glow at night when a light is shone on them.
Cats in general require only about 1/6 the light humans need to see. They have a broad horizontal line of nerve cells near the central portion of their eyes that allows them to have better peripheral vision. This characteristic is especially useful for hunting down those animals that run across a plain. Eyes of the tiger have large lenses and pupils that increase the amount of light let into the eye. This characteristic helps the animal with night vision and even when there are low light levels available. Like all other cats, tiger’s pupil too dilates to let more light enter the eye to increase their vision. Dilated pupils assist in night vision but make focusing on objects up-close difficult.
Hunting: One in Twenty Attempts is successful
Armed with highly camouflaged coat, stealth and massive strength tigers, like many big cats, often fail to capture prey. They often go a week without any success. Dr. George Schaller, an American mammalogist, naturalist, conservationist and author, who studied big cats for many years in their natural environment in Africa, Asia and South America, watched a tiger stalk a dozen times in an area where prey abounded. Only one attempt netted a meal for the animal. He estimates that tigers may have to make at least twenty attempts to catch an animal for everyone that is successful. Schaller further states that the success of the hunt depends largely on the condition of the prey and of the surrounding cover. Not surprisingly, they end up with full bellies when they go after young or weak animals in heavy cover.