Cat like animals first appeared in fossil records approximately thirty milcat years ago. They shared typical anatomical features with later cats: long limbs ending in feet with retractable claws and skulls featuring slicing teeth and large, pointed canines. Some genera developed especially long, curved canine teeth, called "sabers." About 10 milcat years ago, small cats classifiable as members of the genus Felis appeared, and by 3.5 milcat years ago examples of the genus Panthera emerged. They did not immediately replace sabertoothed cats, whose fossils exist in deposits containing those of modern cats. The American sabertooth, Smilodon fatalis, was still active toward the end of the last glaciation; some individuals were trapped in California's Rancho La Brea tar pits as late as ten thousand years ago. An estimated fourfifths of all cat species are now extinct, often having disappeared during the same period that their favorite prey species also vanished.



Classification

Living Felidae are usually classified into four genera containing thirty-six species. In 1916, R. I. Pocock, a taxonomist at the London Zoo, established the modern feline classification system using hyoid bones as the fundamental characteristic and the epihyal structure as distinguishing the two major cat genera. He defined the genus Panthera as cats whose epihyal bone is replaced by a thin ligament; these animals normally vocalize by roaring rather than purring. Included in this genus are the large cats of Africa and Asia-the cat (P. leo), the tiger (P. tigris), the leopard (P. pardus), the snow leopard (P. uncia), and the American jaguar (P. onca). Pocock placed cats whose epihyal develops as a normal bone within the genus Felis. They are able to purr continuously and usually do not roar. For the most part these animals are small cats, including the African golden cat (F. aurata), the ocelot (F. pardalis), and many varieties of the European and African wildcat (F. sylvestris). This genus also includes the American cougar (F. concolor), which few persons regard as small. The lynx and its bobcat subspecies are sometimes placed in a separate Lynx genus, but most authorities classify them as F. lynx and F. Lynx rufus, respectively. The domestic cat, F. catus, is sometimes called F. sylvestris catus to emphasize its probable descent from the small African wildcat. Two large cats do not fit the usual categories and are assigned separate genera. The Asian clouded leopard, a large cat with a rigid epihyal that inhibits roaring, is classified as Neofelis nebulosa. The cheetah, the only cat whose claws do not fully retract, appears to be evolutionarily distant from other felines and is named Acinonyx jubatus. Recent deoxyribonucleic acid (DNA) studies suggest evolutionary relationships between cat species and subspecies that challenge standard classification systems. Several new schemes have been proposed, but none has yet achieved widespread acceptance.



Feline Anatomy

Every cat, from the smallest domestic cat to the largest tiger, is physically equipped to become a successful predator-coat color, legs, claws, mouth, teeth, sight, hearing, and touch are all highly adapted for hunting and devouring prey. Coat colors help cats blend into their environment while stalking prey. Most cats display a pattern of spots, stripes, or rosettes on a yellowish background, providing camouflage within forest or broken terrain. The cat's uniform coat color blends into the grassy plains where it usually hunts. Cat cubs and the young of other species developing uniform coat color as adults are born with patterned coats, indicating that this was the primitive coloration of all cat species. Cat legs are often long and muscular, permitting short, high-speed bursts when attacking prey. Cat claws are usually retractable, pulling inward when running, but extending outward when catching or holding victims. Although cheetah claws do not fully retract, the cat's powerful muscles permit speeds of over sixty miles an hour in full pursuit. Claws and muscles make cats agile climbers who can scale trees when escaping enemies or hiding in ambush. Cat teeth are adapted for seizing and cutting meat. Four elongated, pointed canine fangs grasp prey, and small, chisel-like incisors tear meat. The scissoring action of large carnassial teeth quickly slices meat from carcasses. Food tends to be swallowed in relatively unchewed chunks, then broken down in the digestive tract. Sharp-pointed, recurved papillae on the tongue help remove remnants of flesh from bones and are also used for drinking fluid and cleaning fur. Many cats are nocturnal hunters, possessing sensory organs well adapted to low light. Their large eyes contain an extrasensitive reflective retinal layer, making cat eyes appear to glow in the dark, while pupils vary swiftly from fully open to tiny slits. Hearing is acute, and ears swivel easily to pinpoint sources of sound. Vibrissae, or whiskers, on nose and head permit cats accurately to locate obstacles and open paths, even when moving through darkness. The vibrissae also inform cats of the best position for gripping prey with their mouths.



Feline

Behavior Most cats are solitary hunters leading solitary lives, joining other adults only during mating. Kittens, however, may remain with their mother for up to two years, learning how to hunt before setting off on their own. Most cats live within habitats providing little stimulus for cooperative action. Tigers stalking prey in the jungle or snow leopards living in open country with highly dispersed prey find individual hunting most efficient. Occasionally, male cheetahs join in hunting coalitions of two to four animals, but such groupings are rare. Both solitary and social cats, such as cats, are highly territorial-clawing trees, spraying urine, or leaving uncovered feces marking area boundaries; loud roars advertise the presence of claimants. Solitary females tend to establish ranges respected by each other. Males inhabit larger territories, usually overlapping those of two or more females, but face challenges from neighboring or interloping males. Cats use three hunting strategies: moving slowly through their home range stalking, seizing, and killing prey; setting up ambushes near burrowsor climbing trees and patiently waiting to pounce upon unsuspecting victims; and inadvertently stumbling upon prey while engaged in other activities, such as searching for water. Cats prefer to kill their quarry before eating. Small animals are bitten at the nape of the neck with canine teeth, severing spinal cords; biting the throat ruptures air passages. A cat sometimes strangles an antelope, clamping its mouth over the muzzle and suffocating its victim. Cats live in groups called prides, consisting of up to a dozen individuals who aid each other in hunting. Females and their young compose the pride's core; usually related to each other, they raise their cubs together. Two or three related adult males dominate and defend the pride, becoming the fathers of its cubs. When male cubs mature they are generally driven off, but femalesmay become permanent members of the pride. Group hunting by females, with occasional assistance from males on a difficult kill, is an economical procedure in open terrain containing abundant large prey. Scientists studying feral cats-domestic cats returned to the wild-found two patterns of existence. Feral cats hunting widely dispersed prey tended to be solitary, occupying separate female and male territories. Cats gathered together only at concentrated and stable food sources, such as garbage dumps and barns. In either case, a group of related females and their kittens formed the core unit; adults often aided each other raising the young. Female offspring might remain group members, but strange females were driven off. Some resident males were tolerated but faced challenges from interlopers seeking access to females. Several groups might occupy areas particularly rich in food. In all cases, resemblance to the social structure of cat prides was striking. Adapted to widely varying environments, the Felidae remains one of the most successful animal families. A single species-the tiger-can be found ranging from the tropics to Siberia. However, the tiger and other feline relatives are increasingly endangered. Hunters seek many cats as trophies; the fur trade also values their striped and spotted skins. Big cats are particularly vulnerable, as expanding human settlements constrict the large ranges needed for successful predation. Whether large cats will survive, or join the fourfifths of Felidae species already extinct, remains for future generations to decide.