Introduction to species Cheetahs are classified in the family Felidae, subfamily Acinonychinae as the genus Acynonyx, and species jubatus. The genus contains a single living species. Cheetahs, one of the bigger free-living cats but at the bottom of the pecking order, are unique animals under threat of extinction because of the increasing loss of their habitat and access to prey species.
They generally appear to have a very limited genetic pool and this genetic uniformity is believed to be the result of at least two population bottlenecks followed by natural inbreeding. The first and most extreme bottleneck possibly occurred in the late Pleistocene circa 10, years ago , while the second was more recent within the last century and led to the development of the current South African populations.
Compared to other mammalian species including felids, cheetahs have low levels of MHC major histocompatibility complex proteins diversity, but this phenomenon does not seem to influence its immunocompetence and resistance to diseases of free-ranging cheetahs. Additionally, carnivores in general exhibit significantly lower levels of genetic variation than other mammals do, and several carnivore species for which data are available, exhibit lower levels of heterozygosity and polymorphism than cheetahs do.
There is speculation though that this limited genetic variation may be responsible for the perceived vulnerability of cheetahs in captivity and in the wild. There is a belief that cheetahs, as a consequence of their restricted genetic diversity, tend easily to develop clinical signs of inbreeding depression. These are characterised by high neonatal mortality rates that are partially attributed to their perceived increased susceptibility to infections, the difficulty of breeding them in captivity, and the high frequency of spermatozoal defects in captive, and free-ranging cheetah males.
Many of the phenotypic effects that can be attributed to inbreeding depression, such as infertility, reduced litter sizes, and increased susceptibility to disease are, however, normally limited to captive individuals and this phenomenon may be explained as being physiological or behavioural artefacts of captivity, often as a result of inadequate diets and exposure to stress.
Usually, however, the survival of cubs in the wild too is poor and there is an expected high attrition rate because of a number of factors, predation being one of the more important ones. Cheetahs, as a consequence of this perceived inbreeding, also developed metabolic patterns that are substantially different from those of other cats.
These variations provide major challenges when attempting to compile balanced diets for cheetahs in captivity as their needs differ substantially from those of the other cats. Nutritional deficiencies and imbalances because of inadequate diets in captivity result in increased neonatal mortalities, poor breeding performance, and various fatal conditions in adult animals.
The current contention is that the genetic constitution of cheetahs does not compromise its survival in the wild and plays a limited role in the poor performance of cheetahs in captivity.
Currently the genetic diversity of a metapopulation managed across small reserves is more diverse than that of the free-living population. It is thus important to have genetic information of groups of cheetahs available to allow population management of this threatened species in conservation areas and in small game farms to sustain as much of the genetic variation as is possible. The extent and geographic patterns of molecular genetic diversity of the largest remaining free-ranging cheetah populations reflect limited differentiation among regions and a generally panmictic population panmixia or panmixis means random mating.
Where the genetic diversity has been assessed, measures of genetic variation are similar in cheetahs in all regions of Namibia and they are comparable to Eastern African cheetah populations. In the small and fragmented South African populations, genetic analyses indicate that cheetahs on reserves would not benefit from cross-breeding with the free-roamers but that the free-roamers would benefit.
As the reserve population approaches its overall capacity, mating suppression will be required to avoid selling wild cheetah into captivity. Physical characteristics Male and female Cheetahs are tall and slender animals, with their bodies high off the ground and with long thin legs. Their long tails that may have circular black markings, are distinctive.
They have relatively small rounded heads, short muzzles and round ears, and a distinctive black stripe tear mark from the inner aspects of the eyes to the corner of their mouths. Males are larger than females with an average weight of 54 kg in males and 43 kg in females. Their total length including the tail varies between cm and cm in males and females, respectively.
Their coat is rough and contains numerous round to oval black spots. The background colour is buffy-white but it varies in intensity according to the region and habitat in which they occur. In desert areas, their colour may be quite pale causing them to blend into the colour of the desert sand.
Cheetah cubs are distinctly different in appearance from the adults. They are less distinctly spotted, and have a rug of long lighter hair on the back, sometimes said, to mimic the coat pattern of honey badgers Mellivora capensis who are known to be very aggressive animals. Cryptic animals are often otherwise palatable to their predators so would never survive if obvious. The cheetah is an atypical and the most cursorial having limbs adapted for running felid.
Generally, to maximize its speed, an animal must rapidly swing its limbs to increase stride frequency and support its body weight by resisting large ground reaction forces. As a predator, the cheetah also uses its forelimbs for prey capture and they must therefore also be adapted for this function. Its claws are somewhat dog-like both in shape and the diminished degree of retraction that is intermediate between that of other felids and of wolves.
They are well known, with the exception of the dew claw the first digit which is also retractile , for having blunt, only slightly curved, partly retractile claws, considered to be an adaptation for high-speed locomotion. The reduced manipulative capabilities of the forelimb associated with the evolution of cursorial adaptations seem to have limited the roles of the forepaws in both subduing its prey and feeding. Cheetahs lack the strength of other felids and they are unable to fight their prey to the ground.
Instead they must trip or pull them off balance by hooking the rump of its prey and pulling them off balance with their dew claw while running at high speeds. Cheetahs make various sounds depending on the situation in which they find themselves. When challenged they make a sudden spitting sound reflecting aggression. Normally they communicate with chirping sounds used to locate cubs and members of coalitions.
They purr like domestic cats when pleased. Running ability and speed In nature predator—prey interactions are fundamental in the evolution and structure of ecological communities and within this context cheetahs have evolved the ability to run at speed to capture their prey. Although cheetahs and racing greyhounds are of a similar size and gross morphology, cheetahs are able to achieve far higher top speeds.
They are the best sprinters on earth and are capable of accelerating at a rate of up to 7. However, most cheetah hunts involve only moderate speeds. During a sprint heat production due to muscular activity escalates by about 60 times the rate of heat production at rest. Cheetahs stop running when their rectal body temperature reaches It thus appears that their body temperature determines the distance that they run after which they abandon the chase, if not successful, after a few hundred metres.
Females and trained individuals reach significantly higher speeds compared to males and untrained individuals, respectively. The cheetah possesses several unique adaptations for high-speed locomotion and fast acceleration, when compared to racing greyhounds. Their hind limb bones are proportionally longer and heavier than in grey hounds, enabling the cheetah to take longer strides.
It has a smaller volume of hip extensor musculature than the greyhound, suggesting that the cheetah powers acceleration by using its extensive back musculature. This contention is supported by the presence of extremely powerful psoas muscles that could help to resist the pitching moments around the hip associated with fast acceleration. There is also a proximal to distal reduction in muscle mass on the long bones of the legs, with many of the distal muscles being in series with long tendons.
This configuration reduces the inertia of the limb and thus the amount of muscular work required to swing the limb. However, their running pattern during a chase reflects a different hunting strategy. The chase involves alternating between forward and lateral acceleration the extent of which varies according to the prey species. Thus during a chase, they first accelerate to decrease the distance to their prey, before reducing speed 5—8 s from the end of the hunt to enable them to turn rapidly to match prey escape tactics that can involve sudden directional changes and that are difficult to accommodate with an increasing velocity.
Thus, while the ability to hunt at high speed may enable cheetahs to outrun their prey, they may not always choose to run at maximum speed, especially when chasing prey species that attempt evasion by sudden changes in direction. These hunting strategies require specific anatomical configurations to allow them to generate speed, and to deal with the torque forces generated by the high speed and sudden changes in direction caused by the typical evasive actions of their prey.
The ability of cheetahs to run very fast is the result of a number of anatomical and physiological parameters including: Stride length Cheetahs have an abnormally long stride that contributes substantially to the speeds achieved when running fast. The configuration of its skeletal and muscle structures increases the large, angular movements of the limb joints that, with bending and straightening of the spine, prolong their stride length.
The back muscles, because of their inherent muscle fibre composition, have the ability to produce a strong and quick extension of the spinal column and to increase its rigidity during locomotion thus adding to the force of the forward surge when running. Stride frequency Increasing stride frequency by swinging the limb rapidly and thereby decreasing swing time, also allows quadruped sprinters to reach faster speeds.
Cheetahs, however, generally use a lower stride frequency than greyhounds at any given speed and it appears that stride frequency does not contribute substantially to the high speeds reached by cheetahs. Gait characteristics Mammals use two distinct gallops referred to as the transverse where landing and take-off are contralateral and rotary where landing and take-off are ipsilateral.
The transverse gallop is characteristically that of the horse, while cheetahs use the rotary gallop. The fundamental difference between these gaits is determined by which set of limbs, fore or hind, initiates the transition of the centre of mass from a downward—forward to upward—forward trajectory that occurs between the main portions of the stride when the animal makes contact with the ground. During a stride when their feet are in contact with the ground, animals support their body weight by resisting joint torques caused by the impact.
Quadrupeds typically support a greater proportion of their body weight with their forelimbs during steady state locomotion. The hindquarters thus generate most of the muscular activity required for propulsion.
It is assumed that supporting a greater proportion of body weight on a particular limb is also likely to reduce the risk of slipping during propulsive efforts. Muscle structure and conformation The distribution of skeletal muscle along the legs plays a role in animals that have the ability to reach high speeds and have to accommodating high impact pressures during a chase. In cheetahs the proximal limbs contain many, large, PCSA physiological cross-sectional area muscles. This configuration provides the limbs with the ability to resist and absorb large impacts.
The legs, because of these muscle masses that can absorb some of the impact, do not merely function as simple struts and, because of the muscle distribution, they can absorb much of the force of impact while running. This conformation also provides cheetahs with the ability to control and stabilise their legs during high-speed manoeuvring such as is needed during a chase.
Muscle fibre composition and characteristics Muscle consists of muscle fibres Type I and Type II fibres that have different functional and metabolic characteristics. The characteristic species-specific variations in fibre composition reflect the physiological needs of individual animal species, and in felids generally the fibre type composition of hind limb muscles matches their daily activity patterns. Roaming tigers, for instance, walk long distances, while cheetahs have requirements for speed and power over short distances.
There is a relationship between the amount and type of activity, and the myosin heavy chain MHC isoform composition of a muscle in that tigers have a high combined percentage of the characteristically slower-twitch fibre isoforms required for sustained activity MHCs I and IIa. Cheetah locomotory muscles contain a high proportion of fast-twitch fibres, needed for rapidly swinging their limbs and reducing limb swing-times required for running at speed over short distances.
Enzyme activity in cheetah muscle reflects a high capacity for glycolysis in anaerobically based exercise required for sprinting during high-speed chases for hunting purposes. The fibre type composition, mitochondrial content, and glycolytic enzyme capacities in the locomotory muscles of cheetahs operate at the extreme range of values for other sprinters bred or trained for this activity including greyhounds, thoroughbred horses and human athletes.
King cheetahs The iconic and spectacular king cheetah has become a well-known feature of the cheetahs at HESC. The first recorded description of the king cheetah was from the Macheke district in Zimbabwe in where it was thought to be a hybridisation of a leopard and a cheetah. There the local indigenous population, who had known of its existence for a long time, referred to it as nsuifisi, the hyena-leopard, and told many tales of its fierceness. At a time, they seemed to be more common in parts of Zimbabwe where the colonists in the then Rhodesia referred to them as Mazoe leopards.
Now it is known that what was once considered a separate species Acinonyx rex , is but one of many colour variants that have been described in cheetahs. Other such variants include albinistic, melanistic, cream isabelline , black with ghost markings, and red erythristic with dark tawny spots on a golden background. Blue or grey cheetahs have been described as white cheetahs with grey-blue spots chinchilla or pale grey cheetahs with darker grey spots Maltese mutation.
Some desert region cheetahs are unusually pale probably because it provides a better camouflage in the like-coloured desert http: The last recorded sighting of a king cheetah in the wild was in in the Kruger National Park. They occur naturally in a localised area that covers adjoining portions of Botswana, Zimbabwe, and South Africa northern and eastern regions of the Limpopo Province.