Sunday, January 28, 2001		Nature

Cheetahs hunt with speed
By Nutan Shukla

THE fastest land animal, cheetah, does not always succeeds in its attempts at catching prey. On an average, only half of its chases are successful. The reason is that despite its speed it does not have enough stamina to sustain itself for longer periods in its chases. Usually this member of the cat family can run up to 600 ft after its prey for 20 seconds. If it does not catches up with the prey by then, it aborts the chase.

Built for speed this cat has the smallest head, in relation to its body, in its family. Long legs, without surplus body-weight and an amazingly flexible backbone make it the fastest land creature, gaining the speed of 75 km/h in 2 to 3 seconds, from a standing start, and reaching up to 100 km/h.

Cheetah differs from its cousins in many ways. It hunts during the day, it does not use stealth to catch prey, instead it pursues it in African savannah, unlike other cats cheetah does not have retractile claws and although it prefers the cooler hours at dawn and at dusk for hunting this spotted cat has heat problems.

 
While running its powerful muscles generate enormous amounts of heat. After a 200-yard dash its body temperature rises up to 105 degrees F, a level which can cause damage to the brain if sustained for more than a minute or two. Consequently, to avoid such a situation, it, initially walks down to the nearest spot, moving nonchalantly, and taking good look at the situation. It then shoots to a great speed to pounce on its prey. The critical distance is about 50 yards. If the hunter can make it to that point without ‘spooking’ the prey it has the best chances of making a successful kill.

The fleeing prey runs from side to side, but the pursuer continues in a straight, line. It must anticipate the prey’s route of escape and intercept it. There is an alternative strategy. If the prey is slower than the cheetah, it starts by sprinting after it but then simply follows the prey’s zig-zag route, moving at less than the maximum speed but for longer. The final attack is preceded by one last burst of speed, when the victim is running away. As the cheetah catches up, it swipes the prey’s back legs from under it, straddles the struggling body, and kills the unfortunate creature with a strong bite on the neck.

Once the kill has been made the cheetah does not eat it immediately, but rests for about 15-20 minutes before starting. This is because it is so exhausted and drained of energy and overheated that it must sit and pant in order to cool down. The cheetah always faces the danger of its kill being stolen by other predators. Being a lightly-built cat it has no defence against lions, leopards and hyenas. Even vultures have been known to drive a cheetah away from its kill.

Sometimes a mother cheetah that has caught a young gazelle for her cubs does not kill it. Instead she releases it in front of them and encourages them to chase the animal and finally bring it down. If the gazelle escapes, the mother may retrieve it and release it again to give her cubs another chance. She may even let it go to teach them a lesson. In this way the cubs can perfect their stalking skills and learn the combination of speed and stealth needed to make a successful kill.

A cheetah usually hunts alone, but when her cubs, are about six weeks old they follow her. At four months old they are weaned, and the mother takes them on practice hunts, giving them a chance to try out the skills they have acquired while romping with their litter mates in their first few months of life. Now the ‘paw slap’ they have used endlessly in daily play is used to fell prey. The mother lets her cubs learn from their mistakes, and continues to feed them until they can hunt for themselves.

The ability to learn through trial and error is essential for the survival of many animals. Young badgers get no help from their parents in learning to forage. They enquire into everything, and are quick to discover that turning over stones with their snouts produces food such as works and beetles. They soon learn what tastes good and what does not, and rapidly develop a successful foraging pattern.