Cat Family - biology.

Cat Family - biology. I INTRODUCTION Cat Family, group of carnivorous (meat-eating) mammals considered the most highly developed for killing live prey. Intelligence, acute senses, and agile bodies make cats expert predators. Wild members of the cat family are found worldwide except in Australia and Antarctica. The family includes powerful big cats such as the lion, the leopard, and the tiger, as well as the rugged puma and the high-speed cheetah, along with many smaller, secretive hunters such as the caracal, the ocelot, and the wildcat. The domestic cat, a direct descendent of a small wildcat, has lived alongside humans for thousands of years. Also in the cat family are the now extinct sabertoothed cats. Since prehistoric times, humans have both feared and revered members of the cat family. Their special combination of physical power and ferocity, along with grace and beauty, have earned cats a prominent place in the art, literature, religion, and symbolism of many cultures. In the modern world, however, many wild members of the cat family are threatened with extinction because of hunting by humans and habitat loss. Only the domestic cat thrives everywhere, numbering over 600 million worldwide. Scientists recognize more than 30 species of living cats but have not agreed definitively on how to classify some of these species under genus names. The scientific name for the cat family is Felidae, and cats are often called felids. II HABITAT AND RANGE Cats are found in nearly all natural environments. For example, lynxes live in the icy cold of the Arctic tundra and snow leopards in the high mountains of Asia, whereas sand cats are found in the heat of African deserts and jaguars in the humid tropical rain forests of the Americas. The majority of cat species inhabit forest and woodland environments. Although most cat species are best suited for a particular habitat such as forests or grasslands, a few cats such as the leopard and the puma are highly adaptable, and may even live close to human settlements. Cats are active year-round and do not hibernate. Tropical Asia is home to the greatest number of cat species, including both the biggest--the tiger--and the smallest--the rusty-spotted cat. Only two wild species of cats survive in Europe, the lynx and the wildcat. The cat with the greatest north-to-south geographical range is the puma, found in the Americas as far north as British Columbia and as far south as Chile. The leopard has the widest geographical range of all, spanning much of Africa and Asia, as well as parts of the Middle East. The only cat found in both Eurasia and North America is the lynx. Twelve cats live in the western hemisphere: Geoffroy's cat, the jaguar, the jaguarundi, the kodkod, the little spotted cat (also known as the tigrina or oncilla), the lynx, the bobcat, the margay, the Andes mountain cat, the ocelot, the pampas cat, and the puma (also known as the cougar or mountain lion). III PHYSICAL DESCRIPTION A Anatomy All members of the cat family share a very similar body structure. They have characteristically short faces and small, broad skulls, designed to anchor powerful jaw muscles. Their strong jaws do almost no grinding. Food is cut and chopped with a tooth formation of three pairs of incisors, one pair of canines, two or three pairs of premolars, and one pair of molars in the upper and lower jaws. The molars are modified as formidable shearing teeth, or carnassials, that work together to scrape and cut flesh. The canines in modern cats are conical and pointed. The extinct saber-toothed cats had extremely long and flattened canines, designed for stabbing and slicing. A cat's tongue is covered with sharp, backward-slanted projections, or papillae, which help clean the flesh from the bones of animal prey. All cats are digitigrades--they walk on their toes with the back part of the foot raised. The forefeet have five toes and the hindfeet have four. The paws are well padded. The claws are long, sharp, and, with the exception of the cheetah, completely retractile--they can be drawn in so the paw can be used without scratching or ripping. Claws can be used for grasping prey, for slashing, or in climbing. Cats have relatively long legs, but their legs are proportionately shorter than in most members of the dog family. Cats are also much better at climbing and leaping than are members of the dog family. As a rule, members of the dog family are better built for long-distance, high-stamina running while most cats are designed for sprinting or for rushing prey from ambush. The cheetah is a specialized exception designed for high-speed running, qualifying as the fastest mammal on Earth. The skeletons of cats have relatively flexible backbones, an aid in leaping, climbing, and running. Most cats also have long tails, used for balance when leaping, running, or making swift turns. The cat with the longest tail is the snow leopard, which climbs on steep rocky ledges. The puma, the jaguarundi, and the cheetah also have very long tails. A few types of cats have shortened tails, including the jungle cat and the fishing cat. The lynx and the bobcat have very short "bob" tails. Many saber-tooths also had very short tails. B Size Male cats are typically larger than females. Body size can vary greatly within certain species such as leopards, pumas, and jaguars. Members of populations in certain geographical regions may be larger or weigh much more than typical individuals of the same species that live elsewhere. The biggest living species of cat is the tiger. The largest males can weigh up to 258 kg (570 lb), exceeding the largest male lions. The smallest cats include the rustyspotted cat and the kodkod, which are about half the size of a domestic cat when fully grown. Unlike breeds of the domestic dog, which range in size from tiny toy varieties to giant mastiffs and Saint Bernards, breeds of the domestic cat are all very similar in size. The largest of all cats is the tiger-lion hybrid called a "liger," the offspring of a tiger mother and a lion father. Such giant hybrids are not known in nature but sometimes occur in captivity when lions and tigers are housed together. Because of a genetic oddity, a liger can grow to twice the size of a normal tiger. The hybrid of a tiger father and a lion mother is called a tigon or tiglon, but it grows no larger than either parent. C Coloration and Fur Male and female cats of the same species typically have the same coloring and fur pattern. A striking exception is the male lion, which develops a mane of long dark hair around its face and neck in adulthood. Cats that live in cold environments typically have longer and thicker fur. The longest fur is found in snow leopards. Some species such as the lynx grow longer fur in winter. Spotted patterns can provide camouflage in many environments, allowing a predator to blend in with leafy plants, dappled shadows, and thick stands of grass. Many cats have coats that are mainly brown, yellow, or gray, often with white underbellies. The cubs of many species of cats have spotted coats, which helps hide them in grass and underbrush from predators. Adult cats that have mainly spotted patterns in their fur include cheetahs, leopards, clouded leopards, jaguars, ocelots, margays, Geoffroy's cat, and servals. Single color coats are found in lions, pumas, and jaguarundis. Some individuals among leopards and jaguars, and more rarely in other species, may have all black fur, a trait known as melanism. Tigers are the only cats with striped fur, a pattern their cubs show at birth. As a result of selective breeding by humans, the domestic cat has the widest range of fur colors of all cats. D Senses D1 Eyesight Members of the cat family have very large eyes that face forward to provide overlapping fields of vision. This arrangement gives cats the best binocular vision of any mammal carnivore, with excellent depth perception and ability to judge distances when leaping. Cats also have a wide field of peripheral vision, allowing them to see to the side as they stare forward. In smaller cats, the pupil of the eye is a slit, permitting rapid adjustments to many light conditions. Larger members of the cat family such as lions, leopards, and tigers have round pupils. All cats have excellent night vision, estimated to be six times more sensitive than in humans. Their eyes contain millions of rods (rod-shaped cells), which can detect shapes and details of objects--but not color--in low-light conditions. Cats also have a special light-reflecting structure beneath the retina called the tapetum lucidum, which makes objects appear brighter at night. This feature makes their eyes appear to glow when caught in a direct beam of light. Cats can also see colors in daylight with a patch of cone cells at the center of the retina. However, most cats are thought to see fewer colors than humans do, limited mainly to green and blue. Cats also have a special transparent "third eyelid" called a nictitating membrane to protect the eye from damage. D2 Hearing Members of the cat family have acute hearing that ranges into ultrasonic frequencies well beyond the human threshold. A number of cat species that mainly live in open rather than forest environments also have special middle-ear structures to help detect low frequency sounds. The outer ears of cats can move independently to pinpoint the direction of faint sounds. Servals have the largest ears of all cats in proportion to body size. D3 Whiskers Cats have special sense-organ hairs called whiskers or vibrissae. These long, thick, somewhat stiff hairs are extremely sensitive to touch and can even detect tiny air currents. They are found mainly on the muzzle, but are also present on the chin, the cheeks, around the eyes, and on the wrists of the forelegs. Members of the cat family use their whiskers to hunt at night and to help position captured prey for a death bite on the throat. D4 Smell Members of the cat family are thought to have a less acute sense of smell than do members of the dog family. Smell probably takes a minor role in hunting compared to hearing and vision. Nonetheless, smell plays a crucial role in social behavior among cats. Cats have scent glands on their cheeks, paws, and tails. They also have anal sacs and use their urine and feces to carry their personal scents as well. Cats mark claims to particular territories using their urine or feces, and by rubbing with their scent glands on trees, plants, or rocks. E Vocalizations Cats produce a wide variety of sounds that can communicate aggression, threats, or fear. Other vocal sounds occur in social contact or invitations to mating, or are used to announce territory. All cats can spit, hiss, growl, snarl, and produce a mewing sound, sometimes as a loud call. Most cats can purr, including cheetahs and pumas. Whether the big cats such as lions, tigers, leopards, and jaguars purr is not known for certain, however. Cats purr by moving muscles in the voice box and the diaphragm as the animal breathes in and out. Most of the big cats can roar. In roaring cats, the hyoid bone that supports the tongue is not completely made of bone as in other cats. Instead, the hyoid is partly cartilage and attaches to flexible ligaments, an arrangement thought to allow deep vibrations to be generated in the throat. Roaring is common in lions, leopards, and jaguars. Tigers can also roar but do not use grunts along with roars to produce a roaring sequence the way the other big cats do. The snow leopard is not reported to roar, although it has the same type of hyoid bone as the roaring cats. The clouded leopard and the cheetah have solid or ossified hyoid bones that cannot generate a roar. Pumas also cannot roar but females sometimes produce a loud scream, which may help attract a mate. IV HUNTING AND DIET Cats are often called hypercarnivores, meaning they eat meat protein to the near exclusion of other foods. Protein sources include meat from mammals, birds, reptiles, amphibians, and fish, but also insects and other invertebrates. Unlike dogs and bears, the molar teeth of cats are not designed to grind plant material. Nonetheless, lions and leopards reportedly eat melons and cucumbers to obtain water. Domestic cats eat grass, which may contain needed vitamins. The margay is said to eat fruit on occasion. Studies suggest cats lack taste buds specialized for detecting sweetness. However, their taste receptors for amino acids are very complex, meaning they likely detect qualities in meat that humans cannot. Cats are superbly designed for hunting, and generally hunt alone. Most cats hunt in dim light, but they may also hunt in the dark and in the daylight. Most commonly, cats rely on stealth to approach intended prey, often using foliage or grass for cover, followed by a rush or leap from ambush. Other tactics used by lions and other large cats include causing panic in a herd of animals, then singling out a young individual or an adult that appears slower or weaker. Cats typically need to overpower or injure the prey before they can kill it. Lions can use their claws and bites on the hindquarters of prey such as a zebra or large antelope. Cheetahs may trip running prey with a paw swipe to a hind leg. Cats typically kill smaller prey by snapping the animal's neck, often with a bite to the top of the neck. Larger prey is subdued and killed by a bite to the underside of the neck that apparently pinches off the blood flow to the brain or strangles the windpipe. The extinct saber-toothed cats may have used their huge canines to slash through neck arteries or to slice the windpipe of victims. Cats are also opportunistic meat-eaters. Large cats often steal the kill of smaller predators, including other types of cats. A pride of lions can chase off a pack of hyenas from a kill and will also take a kill from a leopard or cheetah. Cats also scavenge, but cannot easily crack open heavy bones to obtain marrow. Other predators not in the cat family such as hyenas and, to a lesser degree, wolves, can use strong crushing teeth to break up bones. Cats are often thought of as animals that avoid water, but many species willingly wade into water to catch fish and invertebrate prey. Jaguars, leopards, and tigers often swim to cross bodies of water when hunting. Some smaller cats such as the fishing cat and jaguarundi commonly enter water. V SOCIAL BEHAVIOR Most members of the cat family are solitary and establish home territories after they leave their mothers. This behavior helps to spread the range of cats. Cats typically avoid other members of their species except during courtship and mating. Except in lions, females raise their young alone. The age at which cubs leave their mother depends on the size of the cat. In the larger species, the young stay with their mothers for many months after weaning to learn hunting skills. They typically remain in their mother's territory for a time afterward even if they begin to hunt alone. For example, a young tiger may share its mother's territory until it reaches the age of 18 to 30 months, or until its mother has a new cub. The striking exception to this pattern is the lion, which lives in groups called prides. A pride consists of a group of closely related females--often mothers, sisters, and daughters--who hunt and raise cubs together. One or more male lions protect the pride and have mating rights. Other males may drive off or kill the ruling male and take over the pride. Two or more male lions may live and hunt together as a coalition, sometimes as heads of a pride. Two or three male cheetahs sometimes form coalitions and hunt together, but female cheetahs remain solitary, only accompanied by their own cubs. VI REPRODUCTION Members of the cat family are territorial, and males and females typically maintain their own home ranges in the wild. In some species, a number of females maintain separate territories within the larger territory of a single male. Before a female enters estrus and becomes fertile, she makes her desire to mate known with scent marks and calls. Males attracted to the female enter her territory but are not allowed to mate immediately, and typically have to wait a few days for the female to be ready. If more than one male arrives, the males may fight for mating rights. Courtship requires persistence from the male, who is usually met at first with resistance from the female. Playful, ritualized fighting often occurs between a male and a female, which helps stimulate the partners. Females may even bite or attack a male, but the male suitor does not retaliate. In many cats, the receptive female lies with her belly flat on the ground and is mounted by the male. During mating, a male may bite the loose fur on the back of the female's neck. Copulation is usually repeated many times, which appears to help stimulate the female to ovulate. The gestation period after fertilization varies according to the size of the cat, with about 100 days being average for the largest cats, 80 days for the medium-size ocelot, and 65 days for the domestic cat. The number of young born also varies, sometimes based on availability of food. The ocelot and closely related cats usually have one kitten. Other smaller cats may have two or three young in a litter. The wildcat and its descendant the domestic cat typically have three or four kittens at a time. The big cats such as lions, tigers, leopards, and jaguars may have one to four cubs. Cheetahs may have from four to eight cubs. Kittens and cubs are born blind. They feed on milk for an extended period until their mothers introduce them to meat. Mother cats often supply stunned or slightly injured prey to their offspring to help them learn to kill and to hunt. VII EVOLUTION OF CATS A Origin and Early Forms of Cats The cat family is part of the Carnivora, a group of meat-eating mammals that originated during the Eocene Epoch. The earliest members of the Carnivora were small animals such as Miacis, a primitive predator that may have resembled a weasel or a civet. Miacis is thought to be a common ancestor to cats, dogs, bears, and other carnivores. During the Eocene carnivores evolved into two separate branches, with one branch being more closely related to cats and another branch more closely related to dogs. As a result, cats are genetically closer to hyenas and civets than they are to dogs, bears, raccoons, and weasels. The first ancestors identifiable as cats appeared about 35 million years ago during the Oligocene Epoch as relatively small animals with more teeth than modern felids. About 20 million years ago during the Miocene Epoch the cat family split into to two distinct groups--one that led to the modern cats and another that led to the now extinct saber-toothed cats. B Modern Cat Groups Until recently, zoologists often classified the smaller species of modern cats together in the single genus Felis, with the big cats usually kept separate as species of the genus Panthera and the cheetah in its own genus, Acinonyx. Much of this classification system has been changed based on DNA work and other genetic studies that suggest a complex history that separates living members of the cat family into eight distinct lineages. Many cats formerly classified as species of Felis do not have the same common ancestors and so are not grouped together. Nonetheless, hybrids between different species of cats are often fertile and can produce fertile offspring. The eight cat lineages branched from each other at different times over the past 11 million years as the ancestors of modern cats spread from Asia to different parts of the world. Ancient changes in sea level created temporary land links that allowed cats to cross between continents and regions now separated by water. In other cases, sea levels that were as high, or higher, than today separated groups of cats. Both migration and separation affected cat evolution. Most notably, some types of cats that evolved in the Americas from Asian ancestors later migrated back into Asia. Examples include the cheetah--which spread from North America to Asia, and then to Africa--and the lynx--which spread from North America into Asia and into Europe. The different types of living cats belong to the following groups: o The big cats (lions, tigers, leopards, jaguars, and snow leopards) along with clouded leopards form a genetic group that originated in Asia. o The puma, the jaguarundi, and the cheetah form a genetic group whose earliest ancestor entered the Americas from Asia about nine million years ago. o The lynx and the bobcat also originated in North America from Asian ancestors. o The ocelot, the margay, and other small- to medium-size cats that inhabit Central and South America form a genetic group whose cells have 36 chromosomes instead of 38, the number in all other cats. o The caracal, found in Africa and eastern Asia, and the serval, found only in Africa, form a distinct lineage. o Wildcats make up the Felis group and include the direct ancestor of the domestic cat. o The Asian leopard cat group includes the fishing cat, Pallas's cat, and the rusty spotted cat. o The bay cats are a separate genetic group of small cats now found in southeast Asia. VIII CAT FAMILY MEMBERS AND HUMANS A Ancient Relations with Cats The ancestors of humans lived alongside big cats and saber-tooths for millions of years. Early hominids were likely prey for big cats and other large predators. However, hominid species may have scavenged kills made by big cats and their saber-toothed relatives. Hominids could use stones to crack open large bones for marrow, a rich food source not easily available to cats. According to some theories, scavenging of predator kills may have provided a food source that helped early forms of humans spread out of Africa into Asia and Europe around 1.8 million years ago. The earliest direct evidence of how modern humans (Homo sapiens) viewed members of the cat family comes from cave art. Drawings of lions dating to 32,000 years ago were found in 1994 in a cave in Chauvet, France. Lion images carved from mammoth tusk ivory that were found in Vogelherd caves in Germany may be even older. Curiously, no lions shown in ice age art from Europe have manes, suggesting ancient European lions lacked this feature. Images of these formidable predators may have had some spiritual or religious significance for early humans since lions were likely not hunted for food. Later cultures worshipped cats as powerful spirits or representatives of gods. The domestic cat and the lion represented the gods Bast and Sekhmet in ancient Egypt. The jaguar was an important deity or spirit to many Pre-Columbian peoples in the Americas, as was the lion among African peoples, and the tiger in parts of Asia. B Domestication, Hunting, and Captivity of Cats The most important event in relations between humans and cats occurred around 12,000 to 10,000 years ago when a small wildcat began to associate with early human settlements in the Fertile Crescent region of the Middle East. As humans adopted agriculture, stored grain and other food products attracted rodents and other pests that became ready prey for the local wildcat Felis silvestris libyca. Over time some of the wildcats gave up their more aggressive wild behavior to adapt to life alongside people. Humans found the cat a useful animal to control vermin and an enjoyable companion as a pet. DNA from living cats shows that all modern domestic cats around the world are descendants of five females of this wild Middle Eastern subspecies according to research published in 2007. Prior to this DNA study, many experts thought that cats were first domesticated in ancient Egypt around 2500 BC. Other wild members of the cat family have been adopted as pets or kept in captivity for thousands of years. Royalty in Egypt, Persia, and India used cheetahs for hunting as a sport. In ancient Rome, gladiators fought lions and tigers in arena games. The Romans also used big cats and other wild animals to kill condemned prisoners in public spectacles. During the Middle Ages, royalty in Europe sometimes kept captive lions. Big cats have been symbols of royalty in many cultures: lions in Europe and in Africa, tigers in Asia, and jaguars in Central and South America. Members of the cat family have long been hunted to protect livestock or human populations. Cats have also been hunted for sport and for the fur trade. The pelts of spotted cats such as leopards and ocelots have been particularly valued. Body parts from tigers, leopards, and other cats have been used in traditional medicine and in magic. In the modern world, many types of cats are displayed at zoos or at wildlife farms. Trained lions and tigers perform in circuses or in stage shows. Some people keep wild cat species as exotic pets, often raising them from the cub stage. However, owners are sometimes forced to give up their pets when the animals are fully grown and become difficult to control or maintain. Special ranches have been established as sanctuaries to care for big cats once kept as pets or retired from zoos or circuses. More controversial are ranches where exotic cats can be hunted and killed for a fee. Also controversial are tiger farms in Asia that raise tigers to be slaughtered for body parts used in traditional medicine. C Scientific Study Scientific study of cats in the wild has made major progress since the 1960s. At one time, cats had to be monitored visually in daylight, or they were captured and tagged, then recaptured. Radio-tracking of pumas, lions, leopards, and other large cats became widespread in the 1970s. An animal was usually darted with tranquillizers then fitted with a battery-powered radio-collar that would send out signals that could be used to track the cat's movements remotely. Recently, links to global positioning system (GPS) satellites have provided much more precise information about the locations of radio-collared cats. Other methods of studying cats in the wild include installing still-cameras on trails or paths used by cats. The camera photographs any passing animals. Lightintensifying and infrared motion-picture cameras allow researchers to study and record the night-time activities of cats without using spotlights. Some cats have even been fitted with special cameras called "crittercams" to record behavior from the cat's point of view. Cells isolated from droppings (called scat) and shed hair can provide DNA and other genetic information, including how cats in a given area may be related to each other. IX CONSERVATION ISSUES Some members of the cat family are at a high risk of extinction in the wild and are listed as endangered by the World Conservation Union (IUCN). The most endangered cats include subspecies that have very small populations such as the Spanish lynx, the snow leopard, the Amur leopard, the Arabian leopard, the Asiatic cheetah, and the Asiatic lion. The puma subspecies in Florida known as the Florida panther is also highly endangered. Tigers are endangered in nearly all areas where they are found. Other members of the cat family are listed as vulnerable by the IUCN, meaning they could be threatened with extinction in the future if conditions change. Leopards over much of their range, cheetahs in Africa, clouded leopards, and jaguars fall into this group, along with some species of smaller cats. The International Convention on Trade in Endangered Species (CITES) lists cats and cat-derived products that cannot be exported or require special permits. Major threats to cats include loss of habitat from deforestation, and from expansion of farm lands and urban areas. Cats may lose their natural prey and be forced into smaller and smaller territories to find food and shelter, bringing them into contact with humans. Lions, leopards, and cheetahs that attack domestic animals can be shot legally in many African countries. Diseases such as distemper have been spread from domestic dogs living near parks in Africa to lions and other wild predators. As populations fall, inbreeding and lack of genetic diversity can become a problem, making affected cat populations more susceptible to disease, infertility, and physical abnormalities. Illegal hunting or poaching for pelts, meat, and body parts also takes a heavy toll on some cats such as tigers and snow leopards. Conservation groups devoted to saving cats include the Cat Specialist Group (CSG), the Small Cat Conservation Alliance, and the Cat Action Treasury (CAT), as well as the Cat Survival Trust, Project Tiger, and the International Snow Leopard Trust. Activities include establishing parks, reserves, and other protected areas for cats in the wild. Additional approaches include zoos and special facilities where endangered cats can be protected and bred in captivity. Conservationists and biologists have reintroduced some cat species such as the cheetah, the ocelot, and the lynx back into areas where they previously lived but had disappeared. Scientific classification: Cats make up the family Felidae, of the order Carnivora. The tiger is classified as Panthera tigris, the lion as Panthera leo, the jaguar as Panthera onca, and the leopard as Panthera pardus. The mainland clouded leopard is classified as Neofelis nebulosa, and the cheetah as Acinonyx jubatus. The Canada lynx is classified as Lynx canadensis (formerly Felis lynx), and the bobcat as Lynx rufus. The ocelot is classified as Leopardus pardalis (formerly Felis pardalis), the pampas cat as Leopardus colocolo (formerly Felis colocolo), Geoffroy's cat as Leopardus geoffroyi or Oncifelis geoffroyi (formerly Felis geoffroyi), the kodkod as Leopardus guigna (formerly Felis guigna), the little spotted cat or tigrina as Leopardus tigrinus (formerly Felis tigrina), the margay as Leopardus wiedii (formerly Felis wiedii), and the Andes mountain cat as Leopardus jacobita (formerly Felis jacobita). The puma is classified as Puma concolor (formerly Felis concolor) and the jaguarundi as Puma yaguarondi or Herpailurus yaguarondi (formerly Felis yaguarondi). The wildcat is classified as Felis silvestris and the domestic cat as Felis silvestris catus. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.