Cheetah

I

Introduction

Cheetah, member of the cat family, and one of the fastest land animals in the world. A cheetah can accelerate to a running speed of more than 97 km/h (60 mph) in just two to three seconds, sustaining that speed for up to 300 m (1,000 ft). Until about 100 years ago cheetahs were found in open habitats throughout Africa, the Middle East, and southwest Asia as far as central India. Excessive hunting and habitat destruction have reduced the cheetah’s range to isolated parts of Africa south of the Sahara, where around 10,000 cheetahs now live. Fewer than 100 cheetahs remain in remote areas of Iran.

Scientists classify the cheetah in its own genus because of its physical distinctiveness from other cats, although genetic studies suggest that the cheetah may share a common ancestor with the North American puma. Fossil evidence shows that cheetahs may have originated in North America as early as 3 million years ago and then spread into Eurasia and Africa. Scientists theorize that around 12,000 years ago a significant climate change caused a rapid decline in the cheetah population, with only a small group of cheetahs surviving in Eurasia. Inbreeding (mating between close relatives) likely occurred as this tiny population slowly grew over generations. As a result of this inbreeding, today’s cheetahs lack genetic variation, which may make them less able to adapt to changes in the environment, such as infectious disease or a climate change. Overhunting and habitat destruction place cheetahs at high risk for extinction. Farmers often kill cheetahs to prevent them from threatening their livestock. Scientists have developed breeding programs intended to provide insurance against their extinction in the wild, and they are working with local communities in Africa to reduce conflicts between people and cheetahs.

Scientists primarily study cheetahs in the wild by using radio tracking, in which a collar with a radio transmitter attached is placed around the neck of a cheetah. Scientists monitor the radio transmissions as the cheetah travels in order to track the cat’s whereabouts and learn about its life history and behaviors. Some scientists also keep a photographic archive of individuals within a population. They are able to distinguish one cheetah from another by a distinctive pattern of rings on the tail. This photographic record helps scientists monitor individual cheetahs over the course of their lives.

II

Habitat and Range

Cheetahs are well adapted to dry habitats such as savanna grasslands and semideserts. They can survive for long periods without water, gathering much of the water they need from the body fluids of their prey. Cheetahs prefer open habitats that offer unobstructed views of their surroundings; such habitats make it easier to detect prey as well as predators. When stalking prey, however, cheetahs use the camouflage protection of bush, scrub, and other vegetation.

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Although their populations were greatly reduced during the 20th century, as the 21st century began cheetahs still inhabited a broad section of Africa, including areas of the Sahel, East Africa, and southern Africa. Namibia has the largest population of cheetahs, with about 2,500 individuals. Smaller populations exist in Botswana, Zimbabwe, South Africa, Kenya, and Tanzania.

III

Physical Description

The name cheetah comes from the Hindu word chita, meaning “spotted one,” a reference to the cheetah’s light brown to tawny yellow coat that is covered with round, solid-black spots of various sizes. The spots merge into a band pattern on the end of the tail that is distinctive in each individual cat. A long vertical stripe extends from the lower inside corner of the eye to the edge of the mouth.

Adult cheetahs measure 112 to 140 cm (44 to 55 in) from head to rear end and stand 66 to 94 cm (26 to 37 in) at the shoulder. A long tail extends 61 to 79 cm (24 to 31 in) in length. Cheetahs usually weigh around 39 to 65 kg (86 to 143 lb). Male cheetahs are generally bigger than females, but the size differences between the sexes are not as large as in other big cats, such as lions, tigers, and jaguars.

All cats are speedy runners, but the physical features adapted for speed are developed to the extreme in cheetahs. The cheetah body is well muscled, lithe, and streamlined. The cheetah has long, slender legs and an elongated spine with large muscles for flexing and stretching, enabling the animal to increase its stride length during high-speed chases. The long tail acts as a rudder to maintain balance at high speeds. Enlarged nasal and sinus passages and lungs, as well as an oversized heart, support the extensive oxygen exchange needed during fast runs. For good traction, the small, tough pads on cheetah paws are ridged. The claws are blunt and only slightly curved. The claws partially retract into sheaths, springing out from the sheaths when the cat strikes an animal.

A sprinting cheetah runs in what is called a rotary gallop. Its hind limbs land first, on alternate sides, providing the explosive force needed to flex the spine and float the body with all limbs outstretched off the ground, as if in suspended flight. Next, the forelimbs land, one at a time, followed by a stage when all four feet are gathered directly under the body. Lacking a sweating mechanism, cheetahs internally store the heat produced by a high-speed sprint. As a result, cheetahs must catch their prey or abandon the chase after about 300 m (about 1,000 ft)—any longer and the cheetah’s internal body temperature would rise to lethal levels.

The cheetah has a small skull with a short muzzle, and its jaw is weaker than the jaws of other big cats. Cheetahs have 30 teeth, 15 on each side of the mouth. Their teeth are relatively smaller than those of other cats, leaving more room for the expanded nasal passages that help cheetahs run at such swift speeds. Scissor-like molars slice flesh, and small incisors scrape meat from bones.

Like all cats, cheetahs have excellent vision. The cheetah’s eyes have an elongated fovea (an area in the retina) that gives the cheetah a sharp, wide-angle view of its surroundings. The cheetah uses its vision and its acute sense of hearing and smell to locate and track prey.

IV

Behavior

Cheetahs may live singly or in small groups. Adult females live alone, except when raising cubs. After the cubs leave their mother, the siblings stay together for about six months before females separate from the group to go off alone. Brothers often stay together in groups of two to four, known as coalitions, for the rest of their lives. These coalitions may also include unrelated males. About half of all males live alone. When communicating with one another, cheetahs do not roar; instead they make a variety of vocalizations, including purrs, bleats, barks, and chirps, that sound remarkably like those of a bird.

Cheetahs range over large areas in search of food. In Tanzania, where cheetahs have been best studied, a female’s home range may be as large as 800 sq km (300 sq mi) as she follows prey, such as Thomson’s gazelles, that migrate seasonally over long distances in search of fresh grass. A female’s home range tends to overlap with the home ranges of other females since no one female could defend such a large area, but females tend to avoid each other. Most males also range over huge areas, but about a third of males defend smaller territories that are about 40 sq km (15 sq mi) in size. In addition to abundant prey, important features of a territory include rocky outcrops or clumps of trees and bushes—sites that females choose for giving birth and raising cubs and where males are most likely to breed. Male coalitions often fight fiercely to obtain a territory, which they defend from intrusion by single males.

Cheetahs prey on various species of gazelles, impalas, hares, and young wildebeests. Males in coalitions sometimes hunt cooperatively, enabling them to kill larger animals such as zebras. Unlike most cats, cheetahs hunt during the day, when lions and hyenas that compete with them for prey are less likely to be active. Still, scientists in Tanzania have observed that cheetahs lose 10 to 13 percent of their kills to lions and hyenas. Alerted by the panic of a gazelle herd or by the circling of vultures, lions and hyenas close in and easily drive the more timid cheetah away from a fresh kill.

A cheetah usually stalks prey to within about 10 m (about 33 ft) and then bursts into a sprint to close the gap. About half of these chases result in a kill. Other big cats typically rely on a piercing bite to the neck to kill prey. A cheetah’s weak jaw and smaller teeth require that it grasp the throat of its prey until the animal suffocates, a tactic other big cats use only when killing prey that is larger than they are.