The Story of Whiskers
Technically, whiskers of a feline or canine are not whiskers but are called Vibrissae. Whisking is a behaviour in which facial whiskers of an animal are repeatedly swept back and forth in very short bouts of time, during exploratory locomotion. This is absent in cats and dogs.
The Vibrissae are a type of mammalian hair that are well innervated and are embedded deep and connected with the nerves identifiable with the sensory receptive area of touch in the brain. These are present in almost all mammals and primates except humans.
Why do Tigers need Whiskers ?
Tigers are solitary animals and need to hunt alone. Whiskers aid as extrasensory organs. They are so sensitive that they can detect changes in air flow, temperature etc. The whiskers also help determine the deliverance and position of the fatal bite to the prey. Since Tigers are crepuscular (or even start to explore and hunt before the dawn and after dusk), whiskers act as an extra sensory organ giving a tiger the sense or feel of the surroundings - measuring or estimating distances and direction or even surface texture. To simply put, the whisker tips are equipped with “proprioceptors” which are surrounded by blood vessels and which trigger responses to the brain like any other sensory organ.
Tigers have five different types of Vibrissae or Whiskers.
- Superciliary or Supraorbital (above the eye) – To protect the tiger’s eyes when hunting. These whiskers trigger a protective blink when they come in contact with any vegetation.
- Mystacial (where the moustache would be, on the tiger’s muzzle/snout) – These generally outspan the width of a tiger and allow the tiger to gauge the width of a narrow opening (telling the tiger whether it fits through the opening or not). These whiskers also help the tiger in delivering the exact location, and the amount of bite force to kill the prey.
- Tylotrich (throughout the body) – These in addition to the Mystacial whiskers act as a 6th sensory organ helping the tiger with its spatial abilities, particularly in the dark.
- Genal (on cheek) and Mandibular (under snout) – Tigers have a poor myopic vision (focusing on subjects at close distances). Like the Mystacial whiskers, the cheek whiskers allow a tiger to assess the size of the prey, the bite force needed and the location of the fatal bite.
- Carpal (back of front legs) – These in addition to being pressure sensitive are temperature sensitive. A tiger would often gauge the temperature of water or other surfaces even before it touches the surface physically.
Whiskers also serve as indicators of a tiger’s mood. Droopy whiskers indicate a calm mood. Straight forward whiskers indicate anger or attentiveness. Whiskers pinned back against the cheeks or face indicate fear or stress or worry.
Though whiskers are shed and grow back, I observed that in adult tigers, the size of the whiskers (atleast the Mystacial) is smaller than those in the younger ones.