Environment Insight : Animals
By Bob Chester
Sprinter in Survival Marathon
The cheetah is the fastest land animal on the planet, having been timed at speeds of up to 70 mph (112kph) in short bursts. It is also by far the most ancient of the great cats that are alive today.
Around 3.5 to 4 million years ago, cheetahs were to be found on the four major continents - America, Europe, Asia and Africa - but approximately 10,000 years ago the world's environment underwent drastic changes in climate. Over a few thousand years, 75 percent of all mammal species in North America and Europe died. With other mammal species dying, so did the cheetah, being totally wiped out in America and Europe and severely culled in Asia and Africa, possibly migrating to a more suitable environment as ice covered a large part of the northern hemisphere.
Although the cheetah survived the mass extinction of this Pleistocene Epoch, its numbers were so greatly reduced that all but one species - Acinonyx jubatus - became extinct. So severe was this reduction in population - called a "bottleneck" - that brothers were left to reproduce with sisters, and parents with siblings in order to found the next generation. Inbreeding took place to such an extent that today every cheetah alive might be considered as a twin, sharing almost 99 percent of the same genes; in most species related individuals share only about 80 percent of the same genes.
This lack of genetic diversity due to extended inbreeding has led to low survivorship levels - a large number of cubs fail to reach adulthood - poor sperm quality and a greater susceptibility to disease. If a virus-borne disease were to hit a healthy group of leopards for instance, genetic diversity would ensure that not all would die, only those that were susceptible. With the cheetah though, a single deadly virus could wipe out the world's total population in the wild, for what affects one affects all.
To many people there is a confusion between leopards and cheetahs, both large spotted cats found in Africa. This may have resulted from the fact that, particularly in Asia, cheetahs were commonly termed 'hunting leopards'. The Sumer people of present-day Iraq had tamed cheetahs as pets at least 5,000 years ago, and they were held in high regard in Ancient Egypt, where the Pharaohs kept cheetahs as close companions, believing they would carry their souls to the afterworld. In both cultures the cheetah was admired for its speed, hunting ability and grace.
Noble kings and princes have used cheetahs for hunting throughout the ages, from the Italians and French in western Europe to the great Khans of China, and in India where the animal was considered a prerequisite for royalty - until 1952, when it was declared extinct there. Yet through all these centuries the cheetahs used for hunting were taken from the wild, for they do not breed well in captivity. The 16th century Mongolian ruler Akbar kept detailed records of his lifetime collection of some 9,000 cheetahs, and yet reported the birth of just one litter, from which none of the cubs survived.
While the near extinction of cheetahs in Asia cannot be solely blamed on royal demands for hunting pets, this supply was at times maintained by imports from Africa. Whereas once the cheetah was widely spread in Asia, existing in at least eleven countries, there are today perhaps only 200 left, in Iran and possibly a few stragglers in Russia. Indeed, the world's population of over 100,000 at the end of the 19th century has shrunk to somewhere between 9,000 to 12,500 today. Besides the problems caused by its lack of genetic diversity, the marked decline in numbers can be attributed to such common causes as loss of habitat and reduction of prey base, as well as conflict with livestock farmers. Nor has the setting up of parks and reserves greatly helped, for here the closer proximity of larger predators has reduced the cheetah's ability to survive.
Inhabiting open grasslands, savannas, woodlands and bush country, the cheetah is the most diurnal of cats, seldom active at night and usually resting up during the heat of the day. With medium to small black spots against a background color of yellowish gray, tawny or reddish-brown, the most distinctive feature is the black tear-like stain running down from the inner corner of the eye to the upper lip and outlining the muzzle. The 'thoroughbred' of African cats, it is built for speed, sleek with slender legs and a long tail that acts as a stabilizer to navigate high speed turns. Unlike other cats, the claws are not fully retractable and the cleat-like action of the claws helps them reach such high speeds. Adults may weigh 120-130 pounds (55-60 kilograms) and are almost 7 feet (2.1 meters) in length.
While speed is an essential part of the cheetah's strategy, it has to be utilized with care, for the animal can only sprint for 500 yards (500 meters) or so before rising body temperature and oxygen debt force it to call off the chase. Thus cunning, patience and planning all enter into the equation. Where cover is available, a cheetah uses it like any other cat and shows the same ability to anticipate likely opportunities - like waiting crouched in ambush if game is moving in its direction. In the absence of cover, the cheetah will try the open slow approach, hoping to get within 60 yards (60 meters) of the always alert antelope before they take flight. Yet even then the cheetah does not rush in wildly hoping to make a kill, but carefully selects its target before beginning the charge. Although gazelles and springboks are quick they are no match for a cheetah, who quickly overtakes his prey. The only defense the antelope has is to turn sharply, and if he can dodge the pursuer with three or four sharp turns the cheetah will usually call off the hunt.
When the cheetah is successful it brings down its quarry either by tripping it or by knocking it off balance by hooking its shoulder or flank with a dewclaw. Death does not come swiftly though even when the antelope hits the ground, for although the cat secures a vice-like grip around the throat it can be four to five minutes before it finally chokes the life out of its victim. Having dragged its kill into the nearest cover the exhausted cheetah needs to rest for 30-40 minutes before beginning to feed. This is when it is at its most vulnerable, for hyenas and lions scenting fresh meat may come calling. The cheetah is no protector of its prey and will abandon a kill to other predators rather than risk damage to its spindly legs; around 10 percent of all cheetah kills are claimed by other predators. If undisturbed though the cheetah will eat up to 30 pounds (14 kilograms), leaving behind skin, bones, the digestive tract and the rest of the carcass for later scavengers; unlike the leopard, a cheetah never returns to a kill. Sated, the animal can fast for two to five days before making another kill, although mothers with cubs are kept much busier.
Being a female cheetah is hard work, for on becoming sexually active at around 18 months they separate from their litter mates and settling within their mother's territorial area avoid contact with other cheetahs of either sex, except to mate. Breeding males move much further afield before staking out their territory. After separating from their mothers at 17 to 23 months, it is not uncommon for brothers to form coalitions, sometimes accepting others into the group, although one will dominate and gain most of the mating opportunities. Being territorial animals competing for hunting grounds that are frequently traversed by females, the advantage of a coalition is not just reflected in the group's ability to bring down larger prey. Trios may hold onto a territory for 22 months or more, attacking and sometimes killing any single male that dares to encroach. For pairs this is drastically reduced to less than a year, while the mere 4 percent of single males that manage to gain territorial tenure usually lose it within a matter of months.
Although mating can occur at any time of the year, it reaches a peak after the rainy season. For at this time the Thompson's gazelle and other hoofed mammals congregate in large herds. This attracts female cheetahs, and hence the males. Yet competition for mating opportunities is fierce, and each year many young males are killed - or maimed, which means death by starvation - in battle to attract female attention. Although sperm levels are weak, if the female is impregnated by her selected male the resultant litter may be as many as 8 cubs, although 2-4 is more normal.
After a gestation period of 90-95 days, the blind newborns emerge weighing 5-10 ounces (150-300 grams). Able to crawl, move their head, spit explosively and make soft charring noises, they are totally dependent on their mother. From studies of those few born in captivity, they normally open their eyes at 10 days, walk by day 16 and gain their milk teeth at 20 days. Always wary of predators in the wild, the female cheetah moves her cubs every two days while they are still in this helpless stage. Despite all this motherly care though, cubs fall prey to numerous predators, including lions, hyenas and large eagles, and over half will die within the first three months. At five weeks or so the cubs are led to kills, following mother except when she chases prey, where they could spoil the chances by running ahead. Already weaned, by three months the cubs are even more closely attached to their mother, for the family feeds together without disagreement over even the smallest kill. At six months of age the cubs get their first lessons in how to hunt, and by nine months they can hunt and capture hares and fawns. It usually not before 15 months however, that they master the art of killing.
That the cheetah's survival is precarious is borne out by life expectancy figures - up to 15 years in captivity, compared to 4-5 years in the wild. The world's largest cheetah population exists in Namibia, but even here this has halved in the past decade, as the democratic nation grows more prosperous and desirous of land. Today classified as critically endangered, this most ancient and athletic of the big cats is sprinting hard to remain in the survival marathon.
Published in Roving Insight Magazine